{"version":"1.0.0","segments":[{"startTime":5.565,"endTime":10.625,"body":"I wanna talk about what it actually means, um, to limit the temperature increase, uh,"},{"startTime":10.625,"endTime":13.325,"body":"above, uh, to 1.5 degrees above pre-industrial levels."},{"startTime":13.945,"endTime":18.966,"body":"Um, I'll talk about some of the implications of allowing warming to go above 1.5"},{"startTime":18.966,"endTime":19.301,"body":"degrees that we considered in the, uh, IPCC reports, the intergovernmental panel on climate change"},{"startTime":19.301,"endTime":19.635,"body":"reports on 1.5 degrees, uh, which really catapulted me into this, uh, debate, uh, when"},{"startTime":19.635,"endTime":19.97,"body":"I, I was one of the, uh, coordinating lead authors of that report back in"},{"startTime":19.97,"endTime":34.365,"body":"2018."},{"startTime":35.065,"endTime":42.035,"body":"Um, and, you know, I'll come back to this narrative of deadlines and how deadlines"},{"startTime":42.035,"endTime":42.965,"body":"are important."},{"startTime":42.965,"endTime":46.527,"body":"They're quite, they can be useful for people, uh, but they can also be quite"},{"startTime":46.527,"endTime":46.765,"body":"dangerous."},{"startTime":46.985,"endTime":49.778,"body":"Um, and we need, so we need to understand what's happening and what it all"},{"startTime":49.778,"endTime":49.965,"body":"means."},{"startTime":50.785,"endTime":53.605,"body":"Um, but first of all, you know, we live in interesting times."},{"startTime":53.625,"endTime":58.043,"body":"And, and thanks to John for help with getting the data read in last night"},{"startTime":58.043,"endTime":58.338,"body":"for this plot, um, I gave the last Gresham lecture, the, the seventh in the"},{"startTime":58.338,"endTime":64.525,"body":"series, uh, in September of this year."},{"startTime":64.944,"endTime":68.409,"body":"You probably heard September was a pretty, well, you probably noticed it was a pretty"},{"startTime":68.409,"endTime":69.565,"body":"warm month in the uk."},{"startTime":69.565,"endTime":71.285,"body":"It was also a very warm month globally."},{"startTime":71.865,"endTime":75.005,"body":"Um, there it is at the end of that, um, series."},{"startTime":76.225,"endTime":82.24,"body":"It was the hottest month recorded, um, relative to the average for that month over"},{"startTime":82.24,"endTime":84.245,"body":"the past, um, 150 years."},{"startTime":85.065,"endTime":88.654,"body":"And, um, but you can see, and there was a lot of talk at the"},{"startTime":88.654,"endTime":92.005,"body":"time of, you know, does this mean climate has cost a threshold or something?"},{"startTime":92.025,"endTime":96.131,"body":"But we have a big El Nino going on in the Pacific, uh, at the"},{"startTime":96.131,"endTime":96.405,"body":"moment."},{"startTime":97.225,"endTime":101.125,"body":"And, um, the last time we had a big El Nino in the Pacific was"},{"startTime":101.125,"endTime":101.645,"body":"in 2016."},{"startTime":102.505,"endTime":107.143,"body":"And you can see that we had a big spike in global temperatures back then,"},{"startTime":107.143,"endTime":107.452,"body":"and that what happened in September was more or less what we'd have expected to"},{"startTime":107.452,"endTime":114.565,"body":"be when the next big El Nino came along."},{"startTime":114.585,"endTime":118.92,"body":"Now, what was different was that in the last El Nino, the really high temperatures"},{"startTime":118.92,"endTime":120.365,"body":"didn't happen until January, February."},{"startTime":120.865,"endTime":125.823,"body":"So we're watching what happens in this El Nino, um, and we may see higher"},{"startTime":125.823,"endTime":126.485,"body":"temperatures yet."},{"startTime":126.905,"endTime":131.617,"body":"Um, but what is striking about it is that, you know, in many ways what's"},{"startTime":131.617,"endTime":134.445,"body":"perhaps slightly disheartening about it is quite high predictable."},{"startTime":134.445,"endTime":138.266,"body":"What's going on is, I mean, we kind of knew the next big El Nino"},{"startTime":138.266,"endTime":138.52,"body":"was gonna be if it happened, um, eight years after the last storm, which is"},{"startTime":138.52,"endTime":138.775,"body":"what, what's happened, uh, was gonna be a couple of tenths of degree warmer, because"},{"startTime":138.775,"endTime":148.965,"body":"that's the speed with which the world is warming at the moment."},{"startTime":149.425,"endTime":150.725,"body":"And that's exactly what we've seen."},{"startTime":152.305,"endTime":157.576,"body":"And of course, when we, uh, um, and, and, and what's happening in the world"},{"startTime":157.576,"endTime":159.685,"body":"has not gone un gone unnoticed."},{"startTime":160.185,"endTime":164.435,"body":"And if we look back to 2019, I, I love this picture because it's such"},{"startTime":164.435,"endTime":165.285,"body":"a inspiring picture."},{"startTime":165.785,"endTime":170.549,"body":"And I dunno if anybody, um, here in the room was out on these demonstrations"},{"startTime":170.549,"endTime":170.866,"body":"in 2019, the, the, uh, the school strikes, um, where, and one of the big"},{"startTime":170.866,"endTime":179.125,"body":"headlines of the school strike movement was we got 12 years left."},{"startTime":179.585,"endTime":185.685,"body":"And that came directly from the IPCC 1.5 Degrees report, which I was involved in."},{"startTime":186.185,"endTime":190.539,"body":"And I'll talk a little bit about where that narrative, you can see this, you"},{"startTime":190.539,"endTime":190.829,"body":"know, the banner 12 years, um, was, was very prominent in that, uh, in, in"},{"startTime":190.829,"endTime":195.765,"body":"those school strikes."},{"startTime":196.265,"endTime":200.332,"body":"And I spent a lot of time during 2019 that, that, that summer, um, going,"},{"startTime":200.332,"endTime":200.603,"body":"going to the school strikes, actually, I was wearing, we, we, um, a colleague had"},{"startTime":200.603,"endTime":205.485,"body":"some T-shirts printed up."},{"startTime":205.945,"endTime":207.645,"body":"I'm a climate scientist asked me a question."},{"startTime":207.705,"endTime":210.645,"body":"So we wore these T-shirts and went down to the school strikes."},{"startTime":210.865,"endTime":215.018,"body":"And one of the best interactions I had was I was, I was sitting on,"},{"startTime":215.018,"endTime":215.295,"body":"on the tube on my way to the strike, uh, to the school strikes in"},{"startTime":215.295,"endTime":219.725,"body":"Trafalgar Square."},{"startTime":220.505,"endTime":226.04,"body":"And a, uh, a a a sort of elderly gentleman was sort of looking at"},{"startTime":226.04,"endTime":227.885,"body":"me slightly quizzically, sitting opposite."},{"startTime":227.905,"endTime":229.885,"body":"And I was wearing, I, I, I had had a jacket on."},{"startTime":229.885,"endTime":230.525,"body":"I thought it was quite hot."},{"startTime":230.525,"endTime":232.165,"body":"And I took my jacket off, and I thought, okay, here we go."},{"startTime":232.165,"endTime":232.565,"body":"What's gonna happen?"},{"startTime":233.145,"endTime":236.595,"body":"And, uh, and he said, do you mind if I, I I'm gonna ask you"},{"startTime":236.595,"endTime":240.045,"body":"a question in a very sort of like, and I thought, okay, here we go."},{"startTime":240.185,"endTime":244.815,"body":"But it turned out, actually he was a, um, he was, uh, heavily involved in"},{"startTime":244.815,"endTime":247.285,"body":"sustainability himself, and this is what he did."},{"startTime":247.285,"endTime":251.565,"body":"And he actually asked me quite a technical question about, um, about climate change solutions."},{"startTime":251.625,"endTime":253.605,"body":"So you should never judge a book by its cover."},{"startTime":254.025,"endTime":259.274,"body":"Um, but, uh, anyway, back to, um, uh, 2019 and the 12 year, uh, deadline,"},{"startTime":259.274,"endTime":261.725,"body":"uh, which was all over the place."},{"startTime":262.024,"endTime":266.205,"body":"Um, we had school strikes all over the world led by Greta Thunberg."},{"startTime":266.465,"endTime":270.325,"body":"And I love that picture of Greta Thunberg giving to death, stare to Donald Trump."},{"startTime":271.185,"endTime":278.067,"body":"Um, and you know, the origin of this was, um, just, you know, a few"},{"startTime":278.067,"endTime":278.525,"body":"years earlier, we had, um, the Article two of the Paris Agreement, which introduced much"},{"startTime":278.525,"endTime":278.984,"body":"to everybody's surprise, this target of holding the increase of green, the holding the, uh,"},{"startTime":278.984,"endTime":279.443,"body":"increase of global mean temperature above pre-industrial to well below two degrees, and pursuing efforts"},{"startTime":279.443,"endTime":301.925,"body":"to limit the warming to 1.5 degrees."},{"startTime":301.995,"endTime":304.205,"body":"That was the, the wording they agreed on in Paris."},{"startTime":304.505,"endTime":308.57,"body":"And I say, much to everybody surprised it, it definitely took me and most of"},{"startTime":308.57,"endTime":309.925,"body":"the academic community by surprise."},{"startTime":310.165,"endTime":313.965,"body":"'cause up until that time, the, the target was basically two degrees."},{"startTime":314.025,"endTime":315.605,"body":"Two degrees was considered a good result."},{"startTime":316.385,"endTime":320.045,"body":"Um, and that was what they agreed back in."},{"startTime":320.875,"endTime":325.432,"body":"Well, they sort of started to agree it in Copenhagen in 2009, but then Copenhagen"},{"startTime":325.432,"endTime":325.736,"body":"rather felt bits, and then they, they reconvened in Durban the following year, and they"},{"startTime":325.736,"endTime":332.725,"body":"managed to agree on two degrees as the goal."},{"startTime":333.105,"endTime":336.445,"body":"And a lot of countries were very unhappy with two degrees being the goal."},{"startTime":336.445,"endTime":341.202,"body":"They, they saw, you know, that they were gonna suffer a lot from a two"},{"startTime":341.202,"endTime":341.519,"body":"degree of warming, and were pursuing this, uh, and consistently pursuing an agenda, um, to"},{"startTime":341.519,"endTime":349.765,"body":"make ratchet up the ambition of the UN process to 1.5 degrees."},{"startTime":349.765,"endTime":351.285,"body":"And they secured this in Paris."},{"startTime":351.945,"endTime":355.085,"body":"And, um, as I say, it caught the academic community vice price."},{"startTime":355.085,"endTime":358.781,"body":"Perhaps it, it shouldn't have done, because if we'd have been sort of more engaged"},{"startTime":358.781,"endTime":361.245,"body":"with the negotiations, we'd have known what was going on."},{"startTime":361.305,"endTime":362.805,"body":"But, but we, we didn't."},{"startTime":363.065,"endTime":368.094,"body":"Um, and, uh, it also, um, you know, put us, uh, on, on our metal"},{"startTime":368.094,"endTime":368.765,"body":"straight away."},{"startTime":369.305,"endTime":375.766,"body":"Um, because, uh, one of the first things that, um, happened, um, was that the,"},{"startTime":375.766,"endTime":376.196,"body":"as, as a condition I believe, of agreeing to the 1.5 degree goal going into"},{"startTime":376.196,"endTime":376.627,"body":"the Paris Agreement, the countries who were rather skeptical about 1.5 degrees insisted that they"},{"startTime":376.627,"endTime":377.058,"body":"commission a report from the governmental pan, uh, governmental panel on climate change on 1.5"},{"startTime":377.058,"endTime":398.165,"body":"degrees to answer, to answer two questions."},{"startTime":398.865,"endTime":403.378,"body":"Um, what would, what was, what difference would it make limiting warming to 1.5 degrees"},{"startTime":403.378,"endTime":405.485,"body":"versus allowing it to go to two?"},{"startTime":406.065,"endTime":407.285,"body":"And was it even possible?"},{"startTime":407.535,"endTime":409.645,"body":"Those are the sort of two key questions for this report."},{"startTime":410.265,"endTime":413.591,"body":"And as I say, I was one of the authors dragged in to do this,"},{"startTime":413.591,"endTime":413.813,"body":"and we had to do this, the rules of the intergovernmental panel on climate change"},{"startTime":413.813,"endTime":420.245,"body":"is you don't do research that the Intermental Panel on Climate Change doesn't do research."},{"startTime":421.465,"endTime":426.062,"body":"It assesses the academic literature, um, which was a challenge at the time in, in"},{"startTime":426.062,"endTime":426.369,"body":"sort of early 2016 when we, it was announced they were going to require this"},{"startTime":426.369,"endTime":426.675,"body":"report done in a couple of years, because there was no academic literature on 1.5"},{"startTime":426.675,"endTime":435.565,"body":"degrees."},{"startTime":435.565,"endTime":440.44,"body":"Nobody had ever bothered to consider the possibility that we might limit warming to 1.5"},{"startTime":440.44,"endTime":440.765,"body":"degrees."},{"startTime":440.925,"endTime":442.845,"body":"I mean, it makes us sound very bad and callous."},{"startTime":442.845,"endTime":445.525,"body":"But that was just what, that's what the academic community had done."},{"startTime":445.525,"endTime":449.377,"body":"And so we all worked pretty hard, actually, um, to, and it was a pretty"},{"startTime":449.377,"endTime":450.405,"body":"frenetic couple of years."},{"startTime":451.065,"endTime":455.41,"body":"The Gresham College lecture that you're listening to right now is giving you knowledge and"},{"startTime":455.41,"endTime":455.699,"body":"insight from one of the world's leading academic experts, making it takes a lot of"},{"startTime":455.699,"endTime":460.045,"body":"time."},{"startTime":460.585,"endTime":463.678,"body":"But because we want to encourage a love of learning, we think it's well worth"},{"startTime":463.678,"endTime":463.885,"body":"it."},{"startTime":464.745,"endTime":467.965,"body":"We never make you pay for lectures, although donations are needed."},{"startTime":468.505,"endTime":471.899,"body":"All we ask in return is this, send a link to this lecture to someone"},{"startTime":471.899,"endTime":472.805,"body":"you think would benefit."},{"startTime":473.145,"endTime":477.061,"body":"And if you haven't already, click the follow or subscribe button from wherever you are"},{"startTime":477.061,"endTime":477.845,"body":"listening right now."},{"startTime":478.905,"endTime":480.485,"body":"Now, let's get back to the lecture."},{"startTime":482.525,"endTime":484.585,"body":"Um, Oxford actually played quite a big role in this."},{"startTime":484.585,"endTime":485.625,"body":"We convened a conference."},{"startTime":485.885,"endTime":491.378,"body":"Um, it, it's so happened we had a conference booked, um, for September the following"},{"startTime":491.378,"endTime":491.745,"body":"year."},{"startTime":491.765,"endTime":496.067,"body":"And we just sort of, as soon as the Paris result landed, we just, I"},{"startTime":496.067,"endTime":496.354,"body":"ran into the, the, my unit director and said, look, we're just gonna rebrand the"},{"startTime":496.354,"endTime":502.665,"body":"conference, um, and make it about 1.5 degrees."},{"startTime":502.685,"endTime":505.345,"body":"And it was actually, it was a very, it was a very successful conference."},{"startTime":505.345,"endTime":510.303,"body":"We got a lot of people together, and we got a lot of academic journals"},{"startTime":510.303,"endTime":510.634,"body":"involved as well to help, uh, produce special issues to, to get peer reviewed, lit,"},{"startTime":510.634,"endTime":510.965,"body":"uh, you know, literature, um, out there so that people can understand what the implications"},{"startTime":510.965,"endTime":521.544,"body":"were of 1.5 degrees."},{"startTime":521.565,"endTime":525.745,"body":"And so anyway, we, we got the report done, um, in, in 2018."},{"startTime":526.605,"endTime":531.548,"body":"And, uh, the headline and The Guardian when it came out, we got 12 years"},{"startTime":531.548,"endTime":534.185,"body":"to limit, uh, climate change catastrophe, warms un."},{"startTime":534.185,"endTime":537.365,"body":"And that was really the origin of the 12 year deadline."},{"startTime":537.365,"endTime":540.645,"body":"And the deadline narrative continues, you know, the Guardian loves it."},{"startTime":540.985,"endTime":542.845,"body":"Um, this was five, four years later."},{"startTime":543.705,"endTime":546.645,"body":"Um, world closed, irreversible climate breakdown."},{"startTime":546.865,"endTime":549.525,"body":"Uh, five years later, climate, this is this year."},{"startTime":549.865,"endTime":556.486,"body":"Um, climate crisis, carbon emissions budget is now tiny scientists say, um, the unip, the"},{"startTime":556.486,"endTime":556.928,"body":"United Nations Environment Program releases an annual emission gap report where they look at how"},{"startTime":556.928,"endTime":567.965,"body":"well or badly we're doing, um, at achieving, uh, climate goals."},{"startTime":568.105,"endTime":570.845,"body":"It landed this morning, and this was the cover."},{"startTime":571.625,"endTime":577.889,"body":"Um, I think it's, it's a pretty unfortunate, um, title, really, they've chosen for it"},{"startTime":577.889,"endTime":578.725,"body":"this year."},{"startTime":579.405,"endTime":582.965,"body":"'cause, you know, broken record, yes, lots of weather records are being broken."},{"startTime":582.965,"endTime":586.587,"body":"That's the sort of, you know, but it's, it's, it's also the whole deadline narrative"},{"startTime":586.587,"endTime":589.485,"body":"is starting to sound a bit like a broken record as well."},{"startTime":589.845,"endTime":593.605,"body":"I mean, we're keeping on saying the same thing and the same thing's happening."},{"startTime":593.865,"endTime":601.506,"body":"And, and, uh, um, I, I worry about whether this deadline narrative is really working"},{"startTime":601.506,"endTime":602.525,"body":"for people."},{"startTime":602.745,"endTime":607.285,"body":"It doesn't seem to be, um, and, and is it potentially doing some harm?"},{"startTime":607.545,"endTime":610.245,"body":"And I think maybe we'll come onto that in the questions."},{"startTime":610.985,"endTime":615.565,"body":"So, um, you know, how people reacted back in 2019 was very interesting."},{"startTime":616.225,"endTime":618.885,"body":"Um, we kicked off the school strikes, of course."},{"startTime":619.665,"endTime":623.848,"body":"Um, here's a tweet, uh, from a a, a millennial, um, saying, uh, uh, if"},{"startTime":623.848,"endTime":624.126,"body":"you can't read it from the back, uh, uh, Tom Elliot, um, is saying, um,"},{"startTime":624.126,"endTime":624.405,"body":"we're like, you know, millennials are saying, we're like, the world is gonna end in"},{"startTime":624.405,"endTime":634.445,"body":"12 years if we don't address climate change."},{"startTime":635.185,"endTime":640.236,"body":"And Alexandria Ocasio-Cortez, who's a, uh, uh, progressive Democrat, uh, in the US Congress, um,"},{"startTime":640.236,"endTime":640.572,"body":"picked up on this and, you know, pointed out, you know, the UN says, we've"},{"startTime":640.572,"endTime":640.909,"body":"got 12 years left to fix climate change and, and gave a link to the"},{"startTime":640.909,"endTime":651.685,"body":"Guardian, um, article there."},{"startTime":653.225,"endTime":654.365,"body":"So that was the reaction."},{"startTime":654.705,"endTime":657.565,"body":"And of course, there was inevitably a backlash."},{"startTime":658.505,"endTime":663.86,"body":"Um, of course, I'm, you know, the backlash was strongest in the US because, well,"},{"startTime":663.86,"endTime":665.645,"body":"everything's bigger in the us."},{"startTime":666.465,"endTime":672.321,"body":"Um, and, uh, um, so here's some energy website saying, uh, let's break down the"},{"startTime":672.321,"endTime":675.445,"body":"alarmist talking points, fueling these kids' climate strikes."},{"startTime":675.825,"endTime":681.887,"body":"Um, more specifically, uh, a chap called Bjorn Lomborg, uh, who's quite prominent in these"},{"startTime":681.887,"endTime":685.525,"body":"arguments popped up, um, to say, wait a minute."},{"startTime":685.865,"endTime":690.542,"body":"Um, the UN estimates, um, that climate change by the end of the century will"},{"startTime":690.542,"endTime":694.285,"body":"be equivalent to an income loss of two to 4% of GDP."},{"startTime":694.945,"endTime":697.87,"body":"Um, he loves saying this and loves pointing out, well, that would only be like"},{"startTime":697.87,"endTime":698.845,"body":"a couple of years growth."},{"startTime":699.065,"endTime":705.147,"body":"So we're sort of deferring the, the wealth will be at, um, in 2100 to"},{"startTime":705.147,"endTime":705.553,"body":"2102, you know, so what, um, and these are the estimates he quotes, um, for"},{"startTime":705.553,"endTime":715.285,"body":"those, uh, in support of this, um, from various studies."},{"startTime":715.385,"endTime":716.285,"body":"And we'll come back to that."},{"startTime":716.505,"endTime":721.041,"body":"Um, because I think this, this whole question of, um, you know, what difference does"},{"startTime":721.041,"endTime":721.343,"body":"it make allowing warming to go beyond 1.5 degrees is really the, the, the crux"},{"startTime":721.343,"endTime":726.485,"body":"of this lecture."},{"startTime":727.225,"endTime":731.398,"body":"But I would like to spend a little bit time, 'cause it was my job"},{"startTime":731.398,"endTime":731.676,"body":"on that 1.5 degrees report, to talk to you a little bit about what reaching"},{"startTime":731.676,"endTime":736.685,"body":"1.5 degrees actually means."},{"startTime":737.505,"endTime":743.075,"body":"Um, it, I, I should have pointed out that squiggly line that I plotted last"},{"startTime":743.075,"endTime":748.645,"body":"night, but John's help, um, um, we've already had a month, well over 1.5 degrees."},{"startTime":748.905,"endTime":753.555,"body":"Uh, in fact, I believe yesterday or two days ago, there was a daily temperature,"},{"startTime":753.555,"endTime":755.725,"body":"which was close up to two degrees."},{"startTime":755.885,"endTime":760.057,"body":"I mean, you know, we're getting, if you take it short enough timescale, um, we're"},{"startTime":760.057,"endTime":762.005,"body":"seeing fluctuations that are well up there."},{"startTime":762.305,"endTime":767.06,"body":"But that's not what we meant, uh, or not what the Paris Agreement meant, either"},{"startTime":767.06,"endTime":768.645,"body":"by temperatures reaching 1.5 degrees."},{"startTime":769.105,"endTime":774.117,"body":"Um, it's the warming, um, the, the underlying warming that we're talking about, which is"},{"startTime":774.117,"endTime":777.125,"body":"shown in, in this figure by that orange line."},{"startTime":777.665,"endTime":782.085,"body":"The orange line here shows you the, um, human induced warming."},{"startTime":782.085,"endTime":785.46,"body":"We spent some time in the last lecture talking about how we estimate the human-induced"},{"startTime":785.46,"endTime":785.685,"body":"warming."},{"startTime":785.685,"endTime":788.405,"body":"That's a human contribution to the warming."},{"startTime":789.545,"endTime":795.877,"body":"Um, and if we carry on that warming at the current rate, then uh, we"},{"startTime":795.877,"endTime":796.299,"body":"would, uh, reach one point we estimated back in 2018 that we'd reach 1.5 degrees"},{"startTime":796.299,"endTime":796.721,"body":"sometime around 2040 with a range of uncertainty, sometime between 2030 and early in the"},{"startTime":796.721,"endTime":808.965,"body":"2050s."},{"startTime":810.465,"endTime":816.74,"body":"Um, so the Guardian looked and others, of course, took that range, um, looked at,"},{"startTime":816.74,"endTime":817.158,"body":"okay, we might get to 1.5 degrees as early as 2030, and that was the"},{"startTime":817.158,"endTime":817.577,"body":"origin of the sort of 2030, um, uh, headline, uh, that was fed on into"},{"startTime":817.577,"endTime":830.965,"body":"the 12 year narrative."},{"startTime":831.035,"endTime":837.66,"body":"Well, you can immediately see, you know, okay, um, there's, it's looking at that graph,"},{"startTime":837.66,"endTime":843.845,"body":"you wouldn't say we were only 12 years away from, from, uh, climate disaster."},{"startTime":844.545,"endTime":850.885,"body":"Um, but, um, clearly the impacts are getting worse as the world warms."},{"startTime":850.885,"endTime":852.005,"body":"And we'll come back to that in a minute."},{"startTime":852.545,"endTime":855.873,"body":"But first of all, we've gotta talk a little bit about, you know, what it"},{"startTime":855.873,"endTime":857.205,"body":"actually means to reach 1.5 degrees."},{"startTime":857.555,"endTime":858.165,"body":"What does it mean?"},{"startTime":858.235,"endTime":861.885,"body":"What does it mean for the climate to reach 1.5 degrees?"},{"startTime":862.885,"endTime":867.896,"body":"'cause when you're in a warming world, the traditional definition of climate that we used"},{"startTime":867.896,"endTime":868.23,"body":"to use when I was a graduate student, um, in the, the nineties, it sort"},{"startTime":868.23,"endTime":874.245,"body":"of worked back then."},{"startTime":874.985,"endTime":880.85,"body":"Um, it was, um, the, the World Meteorological Organization defines the climate as the average"},{"startTime":880.85,"endTime":882.805,"body":"over a 30 year period."},{"startTime":883.545,"endTime":889.005,"body":"That's the sort of standard definition of weather, you know, stand of, of average weather."},{"startTime":889.825,"endTime":893.458,"body":"And they insist on a 30 year appearance so that you can average out all"},{"startTime":893.458,"endTime":896.365,"body":"the fluctuations and get a handle on what the weather's normally like."},{"startTime":897.065,"endTime":901.96,"body":"But of course, if the world's warming, if you think about the, if the average"},{"startTime":901.96,"endTime":902.287,"body":"over the most recent available 30 years is always going to be misleading, it'll always"},{"startTime":902.287,"endTime":902.613,"body":"be the world's warming at 0.2 degrees per decade, then it would be 0.3 degrees"},{"startTime":902.613,"endTime":912.405,"body":"two cold."},{"startTime":912.905,"endTime":913.645,"body":"Did I get that right?"},{"startTime":913.675,"endTime":914.125,"body":"More or less?"},{"startTime":914.665,"endTime":915.525,"body":"Um, I think so."},{"startTime":915.925,"endTime":916.845,"body":"Somebody will correct me at the end."},{"startTime":917.235,"endTime":917.525,"body":"Okay."},{"startTime":917.825,"endTime":922.445,"body":"So, um, oh, well, um, it's not warming at that over that period."},{"startTime":922.445,"endTime":925.205,"body":"It wasn't warming at quite, uh, 0.2 degrees per decade."},{"startTime":925.305,"endTime":930.341,"body":"So it's, um, uh, at the, at the rates, the world has been warming or"},{"startTime":930.341,"endTime":930.677,"body":"had been warming up to, uh, 20, uh, 18, um, if you'd just taken the"},{"startTime":930.677,"endTime":931.013,"body":"average over the past 30 years, um, we'd have said that the world was, you"},{"startTime":931.013,"endTime":942.765,"body":"know, quarterly cooler than it actually was."},{"startTime":943.545,"endTime":946.765,"body":"And that's sort of fairly obvious from this graph."},{"startTime":947.425,"endTime":953.56,"body":"Um, but of course, this, you know, when you're talking about, um, something like temperatures"},{"startTime":953.56,"endTime":953.969,"body":"reaching 1.5 degrees in the Paris Agreement, um, this all starts to get quite loaded"},{"startTime":953.969,"endTime":964.605,"body":"because it's not just a, a scientific exercise to work it out."},{"startTime":964.945,"endTime":970.725,"body":"It actually has political and even legal, even financial ramifications."},{"startTime":971.875,"endTime":979.489,"body":"Lots of countries, um, argue that the trigger for what they refer to as loss"},{"startTime":979.489,"endTime":984.565,"body":"and damage payments should be when temperatures cross 1.5 degrees."},{"startTime":984.565,"endTime":986.405,"body":"Other countries strongly disagree."},{"startTime":986.505,"endTime":988.165,"body":"You can imagine which countries are which."},{"startTime":988.705,"endTime":995.71,"body":"But the point is, this has become a, a legal question, um, when we reach"},{"startTime":995.71,"endTime":996.645,"body":"1.5 degrees."},{"startTime":997.345,"endTime":1002.396,"body":"And so, actually, I spent a lot of my time with the inter intergovernmental panel"},{"startTime":1002.396,"endTime":1002.733,"body":"on climate change report on, on this kind of rather ArcHa argument about what is"},{"startTime":1002.733,"endTime":1009.805,"body":"the present day climate, do you think?"},{"startTime":1010.475,"endTime":1011.765,"body":"What a completely stupid question."},{"startTime":1011.825,"endTime":1016.977,"body":"But it's not, it, it becomes quite complicated because the standard world meteorological organization definition"},{"startTime":1016.977,"endTime":1019.725,"body":"would've always been 15 years out of date."},{"startTime":1021.225,"endTime":1026.474,"body":"And, um, as a physicist, uh, I was per, i, I would much prefer to"},{"startTime":1026.474,"endTime":1031.723,"body":"say, well, the climate is the, uh, the moments of the attractor of the weather."},{"startTime":1031.723,"endTime":1032.685,"body":"Everybody knows that."},{"startTime":1032.785,"endTime":1035.005,"body":"And if you're a physicist, that statement means something."},{"startTime":1035.005,"endTime":1036.845,"body":"And if you're not, it probably doesn't mean a huge amount."},{"startTime":1036.845,"endTime":1039.365,"body":"And certainly I just go, if you're a lawyer, it means nothing at all."},{"startTime":1040.145,"endTime":1046.051,"body":"So, um, what I mean is, um, that if you, if you allowed the weather"},{"startTime":1046.051,"endTime":1046.444,"body":"to evolve many, many times, uh, with the same drivers and then took, took the,"},{"startTime":1046.444,"endTime":1046.838,"body":"uh, distribution over the possible states that you found and took the average, that would"},{"startTime":1046.838,"endTime":1059.045,"body":"be the climate."},{"startTime":1060.465,"endTime":1068.622,"body":"Um, but that's too, that was regarded as too esoteric a, um, definition of present"},{"startTime":1068.622,"endTime":1071.885,"body":"day climate for the UN purposes."},{"startTime":1072.665,"endTime":1079.143,"body":"So, um, we, we ended up with a definition of the temperature this year as"},{"startTime":1079.143,"endTime":1079.575,"body":"the temperature we would find if we were able to take a 30 year average"},{"startTime":1079.575,"endTime":1080.006,"body":"with the middle of the 30 years in this year, assuming whatever trend that's happening"},{"startTime":1080.006,"endTime":1093.395,"body":"were to continue."},{"startTime":1095.495,"endTime":1095.785,"body":"Okay?"},{"startTime":1096.005,"endTime":1100.625,"body":"So that's, that's where we landed eventually as a sort of bit of a compromise."},{"startTime":1100.845,"endTime":1104.481,"body":"And, and actually one of the reasons I was, I spent a lot of time"},{"startTime":1104.481,"endTime":1106.905,"body":"worrying about this is, is illustrated by this next figure."},{"startTime":1107.805,"endTime":1110.865,"body":"Um, so we, we talked about these in the previous lecture."},{"startTime":1110.895,"endTime":1117.505,"body":"There's sort of multiple things driving climate on, um, inter-annual timescales."},{"startTime":1118.125,"endTime":1125.065,"body":"The trend is overwhelmingly driven by anthropogenic human induced, uh, increases in greenhouse gases."},{"startTime":1125.405,"endTime":1130.762,"body":"But every now and then, you can see here this blue lines, that's the contribution"},{"startTime":1130.762,"endTime":1132.905,"body":"of natural variability to global temperatures."},{"startTime":1133.525,"endTime":1136.265,"body":"And those dips are associated."},{"startTime":1136.355,"endTime":1137.745,"body":"Those are, those are volcanoes."},{"startTime":1137.805,"endTime":1139.825,"body":"Um, they're the cooling effect of volcanoes."},{"startTime":1139.825,"endTime":1145.803,"body":"We'll, we'll come back to them in a minute, but, um, there was, during 2018,"},{"startTime":1145.803,"endTime":1150.985,"body":"we, we had this very tight deadline for producing this, uh, IPCC report."},{"startTime":1151.365,"endTime":1153.745,"body":"We knew that, um, there was no slip."},{"startTime":1153.765,"endTime":1158.07,"body":"We, there was no opportunity of a slippage because it was sort of fitted into"},{"startTime":1158.07,"endTime":1159.505,"body":"the whole U-N-F-C-C-C negotiation process."},{"startTime":1160.245,"endTime":1164.785,"body":"And all the meantime, there were rumors of a volcano rumbling on in Java, and"},{"startTime":1164.785,"endTime":1166.905,"body":"everybody was saying, oh, it's gonna blow."},{"startTime":1166.975,"endTime":1168.185,"body":"It's gonna be another big one."},{"startTime":1168.365,"endTime":1169.385,"body":"You know, just like that one."},{"startTime":1169.405,"endTime":1174.816,"body":"And I was completely convinced that a matter of months before our final report landed,"},{"startTime":1174.816,"endTime":1179.145,"body":"and by, by the way, these reports are reviewed in painstaking details."},{"startTime":1179.245,"endTime":1185.207,"body":"So once you've, once it's sort of rolling, you know, it, it really is set"},{"startTime":1185.207,"endTime":1188.785,"body":"in stone several months before the final acceptance date."},{"startTime":1189.245,"endTime":1193.538,"body":"And so if this volcano had gone off and then cooled the whole planet down"},{"startTime":1193.538,"endTime":1193.825,"body":"by, you know, a couple of tenths of a degree, it would've been a total"},{"startTime":1193.825,"endTime":1194.111,"body":"nightmare if we hadn't landed the point that the present day temperature is not what"},{"startTime":1194.111,"endTime":1202.985,"body":"we're talking about."},{"startTime":1203.415,"endTime":1209.65,"body":"It's this, you know, background 30 year, this background trend with the 30, 30 year"},{"startTime":1209.65,"endTime":1212.145,"body":"average accounting for the underlying trend."},{"startTime":1212.885,"endTime":1218.443,"body":"So, um, that's what, um, we, we, we, we established, we managed to get that"},{"startTime":1218.443,"endTime":1219.185,"body":"nailed down."},{"startTime":1219.725,"endTime":1226.387,"body":"Um, and, uh, we in fact use the apparatus that I described to you in"},{"startTime":1226.387,"endTime":1226.831,"body":"the previous lecture of attributing temperature changes to different drivers to work out not just"},{"startTime":1226.831,"endTime":1238.825,"body":"a trend, but how much of the trend is due to human influence."},{"startTime":1238.825,"endTime":1244.562,"body":"And that allows us to pull out that orange line, which is the expected response"},{"startTime":1244.562,"endTime":1244.945,"body":"to anthropogenic, to human, uh, factors, um, which allows us to, and we with some"},{"startTime":1244.945,"endTime":1254.125,"body":"uncertainty on that to say where warming had got to."},{"startTime":1254.625,"endTime":1260.007,"body":"So the formal definition of where the warming has got to is where human induced"},{"startTime":1260.007,"endTime":1260.365,"body":"warming has got to, or where this average over a 30 year timescale has got"},{"startTime":1260.365,"endTime":1260.724,"body":"to accounting for the human induced trend, and also removing the impact of any volcano"},{"startTime":1260.724,"endTime":1272.565,"body":"if it had gone off."},{"startTime":1272.585,"endTime":1275.925,"body":"And as it happened, we were lucky and the volcano didn't go off."},{"startTime":1276.205,"endTime":1279.62,"body":"I was, in a sense, I was a little disappointed 'cause I was kind of,"},{"startTime":1279.62,"endTime":1279.848,"body":"we'd done all this prep so that, so that if the volcano had gone off,"},{"startTime":1279.848,"endTime":1285.085,"body":"um, it wouldn't have scuppered the report, but yeah."},{"startTime":1285.085,"endTime":1289.775,"body":"Anyway, it didn't, so, so, so it was all, you know, various colleagues thought I"},{"startTime":1289.775,"endTime":1291.965,"body":"was being completely unnecessary pedantic throughout anyway."},{"startTime":1292.445,"endTime":1296.231,"body":"I, you know, they would've been grateful if it had gone off, you know, that"},{"startTime":1296.231,"endTime":1299.765,"body":"was what I, anyway, so, so, um, so this is how we work out."},{"startTime":1300.185,"endTime":1304.52,"body":"Um, this is how we work out the current level of warming, and that's what"},{"startTime":1304.52,"endTime":1305.965,"body":"we're sort of heading towards."},{"startTime":1307.505,"endTime":1312.651,"body":"Um, as we, um, and if you compare that to the, uh, those decal averages"},{"startTime":1312.651,"endTime":1312.995,"body":"that I showed you earlier on, the sort of WMO definition of average is over"},{"startTime":1312.995,"endTime":1318.485,"body":"30 years."},{"startTime":1319.145,"endTime":1323.9,"body":"Um, you can see that since the 1960s or so, um, most of the warming"},{"startTime":1323.9,"endTime":1325.485,"body":"we've seen is, is intel."},{"startTime":1325.485,"endTime":1329.557,"body":"Well, all of the warming you've seen really is due to human influence, which was"},{"startTime":1329.557,"endTime":1329.828,"body":"the conclusion we talked about in the previous lecture about how it's extremely likely that,"},{"startTime":1329.828,"endTime":1330.1,"body":"um, human influence has been the dominant cause of the observed warming since the mid"},{"startTime":1330.1,"endTime":1338.245,"body":"20th century."},{"startTime":1338.245,"endTime":1340.525,"body":"That's just to connect up this with the previous lecture."},{"startTime":1341.545,"endTime":1349.477,"body":"Um, and, you know, on this basis, we reached one degree in 2017 and, um,"},{"startTime":1349.477,"endTime":1350.006,"body":"uh, on that, that rate, um, we also, um, reached, um, in, you know, on"},{"startTime":1350.006,"endTime":1364.285,"body":"the basis of this record, we reached one degree in 20, uh, 2017."},{"startTime":1364.985,"endTime":1369.672,"body":"Um, also on the basis of this record, this was the record that was available"},{"startTime":1369.672,"endTime":1372.485,"body":"to us at the time, back in, um, 2017."},{"startTime":1374.985,"endTime":1381.63,"body":"Um, the, the, the record was also consistent with the statement that at the time"},{"startTime":1381.63,"endTime":1382.073,"body":"they were negotiating the Paris Agreement, the negotiators were told the world had reached 0.85"},{"startTime":1382.073,"endTime":1389.605,"body":"degrees of warming."},{"startTime":1389.665,"endTime":1394.943,"body":"So that was the, the information that was provided to the negotiators when they were,"},{"startTime":1394.943,"endTime":1395.295,"body":"um, when, when they, when they were arguing over what they were going to agree"},{"startTime":1395.295,"endTime":1395.647,"body":"in Paris, um, they had a very formal system called a structured Expert dialogue, where"},{"startTime":1395.647,"endTime":1409.725,"body":"experts from the environmental panel on climate change gave presentations to governments."},{"startTime":1409.725,"endTime":1412.405,"body":"And this was the number that they, that they gave them."},{"startTime":1413.065,"endTime":1418.821,"body":"Um, and the current level of warming was deemed to be 0.85 degrees above pre-industrial"},{"startTime":1418.821,"endTime":1419.205,"body":"levels."},{"startTime":1419.505,"endTime":1425.042,"body":"And that is indeed roughly the temperature of the decade or decade and a half"},{"startTime":1425.042,"endTime":1425.411,"body":"or so prior to 2015, um, by coincidence, um, conveniently that happened to be a"},{"startTime":1425.411,"endTime":1425.78,"body":"period where global temperatures were quite stable, that you probably can remember the Daily Telegraph"},{"startTime":1425.78,"endTime":1441.285,"body":"would publish a headline saying Global warming stopped in 2000, you know, quite frequently."},{"startTime":1441.865,"endTime":1443.885,"body":"Um, they, they stopped doing that."},{"startTime":1443.945,"endTime":1449.045,"body":"In fact, there was a, there's a, there's a, there's an outfit called the Global"},{"startTime":1449.045,"endTime":1449.385,"body":"Warming Policy Foundation, um, which are various, um, uh, it keeps being revealed, different conservative"},{"startTime":1449.385,"endTime":1455.845,"body":"politicians are members of it."},{"startTime":1456.265,"endTime":1461.443,"body":"Um, but they, um, they, they used to have as their logo, global temperature, um,"},{"startTime":1461.443,"endTime":1464.205,"body":"over the 20th century, over the 21st century."},{"startTime":1464.885,"endTime":1466.005,"body":"'cause it was impressively flat."},{"startTime":1466.785,"endTime":1471.285,"body":"Um, but they've, they've actually abandoned that logo and moved to a, uh, a much"},{"startTime":1471.285,"endTime":1473.085,"body":"more neutral logo I noticed recently."},{"startTime":1473.505,"endTime":1476.085,"body":"Um, because obviously it's sort of, doesn't really work for them anymore."},{"startTime":1476.345,"endTime":1481.125,"body":"Anyway, interesting that, um, I be, I'll get some emails about that afterwards."},{"startTime":1481.125,"endTime":1481.605,"body":"There we are."},{"startTime":1481.605,"endTime":1482.045,"body":"Nevermind."},{"startTime":1482.045,"endTime":1482.685,"body":"Hello everybody."},{"startTime":1483.225,"endTime":1489.551,"body":"Um, but, uh, um, so, um, what that means, you know, with that record, at"},{"startTime":1489.551,"endTime":1489.973,"body":"that rate, it implies we'll reach 1.5 degrees around 2040, um, however, um, and there's"},{"startTime":1489.973,"endTime":1502.205,"body":"of course a range of uncertainty around that, but the record, of course, is uncertain."},{"startTime":1503.085,"endTime":1505.845,"body":"H how, you know, what has actually happened in the past."},{"startTime":1506.785,"endTime":1511.957,"body":"And here's a bunch of estimates, different estimates, you'll notice they are slightly different from"},{"startTime":1511.957,"endTime":1515.405,"body":"each other, um, of global temperatures over the past century."},{"startTime":1516.425,"endTime":1519.405,"body":"And we haven't talked very much about observations in these lectures so far."},{"startTime":1519.505,"endTime":1524.015,"body":"So it's important to recognize that this, you know, I, if I show you a"},{"startTime":1524.015,"endTime":1527.925,"body":"plot of global temperature, there's a lot, a lot has gone into it."},{"startTime":1527.945,"endTime":1532.575,"body":"If you stop and think about, you know, how how on earth do people know"},{"startTime":1532.575,"endTime":1535.045,"body":"what's happened to climate over the past century?"},{"startTime":1535.745,"endTime":1541.1,"body":"And, and the fact is that it's, it's, you know, there's a huge science in"},{"startTime":1541.1,"endTime":1541.457,"body":"this, in, in gathering together observations from all over the world, and particularly when you"},{"startTime":1541.457,"endTime":1541.814,"body":"go back to the 19th century to get that, that baseline that we're measuring against,"},{"startTime":1541.814,"endTime":1557.165,"body":"um, a lot large parts of the world like the Pacific are, are badly observed."},{"startTime":1557.825,"endTime":1563.605,"body":"Um, because the only observing network they had back then was, um, merchant ships."},{"startTime":1564.465,"endTime":1566.885,"body":"Um, and the Royal Navy, in fact played a big role in this."},{"startTime":1566.885,"endTime":1570.485,"body":"They, they, I think it was part of ruling the waves, was you measured their"},{"startTime":1570.485,"endTime":1570.725,"body":"temperature."},{"startTime":1570.785,"endTime":1573.525,"body":"Uh, it seemed to be a sort of fairly standard thing they did."},{"startTime":1573.945,"endTime":1578.909,"body":"Um, but they did it using, um, uh, and this is, this is a, there's"},{"startTime":1578.909,"endTime":1579.239,"body":"an interesting sort of, sort of digression here, but, um, there, there's a remarkable role"},{"startTime":1579.239,"endTime":1579.57,"body":"of this wooden bucket, um, in the history of climate science or these buckets like"},{"startTime":1579.57,"endTime":1579.901,"body":"it because, um, Royal Navy ships used to use these standard wooden buckets, chuck 'em"},{"startTime":1579.901,"endTime":1598.765,"body":"over the side, pull it up, dip a thermometer in, and then record the temperature."},{"startTime":1599.905,"endTime":1601.445,"body":"Um, and then they switched."},{"startTime":1601.705,"endTime":1603.325,"body":"Um, but that was very heavy wooden bucket."},{"startTime":1603.945,"endTime":1609.739,"body":"And so they switched, um, in the sort of nine, they modernized the system, um,"},{"startTime":1609.739,"endTime":1611.285,"body":"to that canvas bucket."},{"startTime":1611.995,"endTime":1612.285,"body":"Okay?"},{"startTime":1613.105,"endTime":1617.749,"body":"But the problem with the canvas bucket is that it's canvas, wet canvas being dragged"},{"startTime":1617.749,"endTime":1622.085,"body":"up the side of a ship in a howlin gale is gonna cool off."},{"startTime":1623.185,"endTime":1624.845,"body":"And that's exactly what you see happening."},{"startTime":1624.845,"endTime":1629.445,"body":"Wooden buckets, suddenly they introduced canvas buckets, and it got a whole lot colder."},{"startTime":1629.785,"endTime":1631.325,"body":"The world got colder, apparently."},{"startTime":1631.785,"endTime":1635.066,"body":"Um, and then they, and then they realized that was the canvas buckets weren't very"},{"startTime":1635.066,"endTime":1635.285,"body":"reliable."},{"startTime":1635.285,"endTime":1639.165,"body":"So they introduced these modern insulated rubber buckets, okay?"},{"startTime":1639.465,"endTime":1640.885,"body":"And the world warmed by half a degree."},{"startTime":1640.995,"endTime":1641.285,"body":"Boom."},{"startTime":1641.595,"endTime":1641.885,"body":"Okay?"},{"startTime":1642.185,"endTime":1646.91,"body":"So now fortunately they've kept all these gadgets and, you know, people like David Parker"},{"startTime":1646.91,"endTime":1647.225,"body":"spent a admirable amount of time chucking 'em over the sides of ships in various"},{"startTime":1647.225,"endTime":1653.525,"body":"different weather conditions to work out."},{"startTime":1653.785,"endTime":1657.547,"body":"So it's not, this is not this, fortunately because we've kept all the how, not"},{"startTime":1657.547,"endTime":1659.805,"body":"just the records, but how the records were made."},{"startTime":1660.235,"endTime":1666.145,"body":"It's possible to make, to correct for these things and, um, to gather the stage"},{"startTime":1666.145,"endTime":1670.085,"body":"together and, and, and, and establish, um, what actually happened."},{"startTime":1670.345,"endTime":1675.928,"body":"But as you might imagine, these corrections, and in particular, the method you use to"},{"startTime":1675.928,"endTime":1676.301,"body":"fill in the gaps in a record going back over a century, do affect the"},{"startTime":1676.301,"endTime":1681.885,"body":"outcome."},{"startTime":1681.885,"endTime":1682.325,"body":"They do."},{"startTime":1682.325,"endTime":1686.086,"body":"They do, they do, they do affect the, the estimate you end up with a"},{"startTime":1686.086,"endTime":1688.845,"body":"little bit, not, not, not, you know, massively so, but enough."},{"startTime":1689.305,"endTime":1691.565,"body":"And, uh, as the record gets updated."},{"startTime":1691.905,"endTime":1697.765,"body":"So here was the record that we were using, it's now been updated in 2021."},{"startTime":1698.145,"endTime":1703.597,"body":"And you'll notice the impact of the update is to make it a little bit"},{"startTime":1703.597,"endTime":1704.325,"body":"warmer today."},{"startTime":1705.145,"endTime":1706.805,"body":"But of course, if you stop and think about it, wait a minute."},{"startTime":1706.945,"endTime":1708.325,"body":"Now, today didn't change."},{"startTime":1708.995,"endTime":1714.074,"body":"What changed was the estimate of what temperatures were back in the 19th century, because"},{"startTime":1714.074,"endTime":1714.413,"body":"we concluded that the global temperature in the 19th century was about a 10th of"},{"startTime":1714.413,"endTime":1721.525,"body":"a degree cooler than we thought previously."},{"startTime":1722.535,"endTime":1730.22,"body":"Which of course means that, um, you know, 2017 was over 1.1 degree warmer than,"},{"startTime":1730.22,"endTime":1731.245,"body":"uh, pre-industrial."},{"startTime":1731.945,"endTime":1738.31,"body":"Um, and, um, you know, the 2006 to 2015 period, which was 0.85 degrees warmer"},{"startTime":1738.31,"endTime":1738.735,"body":"than pre-industrial, according to the people informing the Paris Agreement, was actually closer to one"},{"startTime":1738.735,"endTime":1745.525,"body":"degree warmer."},{"startTime":1746.705,"endTime":1749.365,"body":"So what do we do with all this information?"},{"startTime":1749.635,"endTime":1754.412,"body":"Because, you know, what that implies is that we'll reach 1.5 degrees, not in 2040,"},{"startTime":1754.412,"endTime":1756.005,"body":"but in the early 2030s."},{"startTime":1757.505,"endTime":1760.485,"body":"Um, and that's where you get to with a certain range of uncertainty."},{"startTime":1761.265,"endTime":1766.223,"body":"And of course, cue more headlines from the Guardian about how close we are to,"},{"startTime":1766.223,"endTime":1766.885,"body":"um, disaster."},{"startTime":1767.865,"endTime":1772.717,"body":"But what's actually changed here, we've changed what we think the temperature was in the"},{"startTime":1772.717,"endTime":1773.365,"body":"19th century."},{"startTime":1773.365,"endTime":1775.805,"body":"That doesn't make any difference whatsoever to what's happening today."},{"startTime":1777.065,"endTime":1782.504,"body":"Um, so, but of course it matters because the governments have agreed that they want"},{"startTime":1782.504,"endTime":1785.405,"body":"to limit warming to 1.5 degrees above pre-industrial."},{"startTime":1785.905,"endTime":1788.125,"body":"And, you know, if we got it wrong, we got it wrong."},{"startTime":1788.225,"endTime":1792.005,"body":"And, you know, that's, that means that we're gonna get to 1.5 degrees earlier."},{"startTime":1792.545,"endTime":1793.205,"body":"But it doesn't."},{"startTime":1793.265,"endTime":1797.755,"body":"But what this should tell you is sometimes when you read the headlines, you might"},{"startTime":1797.755,"endTime":1802.245,"body":"think that something very dramatic is going to happen exactly when we reach 1.5 degrees."},{"startTime":1802.585,"endTime":1807.203,"body":"And I'm telling you this little anecdote because it shows that, you know, it's, it's"},{"startTime":1807.203,"endTime":1807.511,"body":"even what 1.5 degrees means is vague to within a tent or two of a"},{"startTime":1807.511,"endTime":1807.819,"body":"degree, because, you know, what we thought 1.5 degrees meant back when we were negotiating"},{"startTime":1807.819,"endTime":1820.445,"body":"the Paris Agreement is slightly different from what we think it means now."},{"startTime":1821.265,"endTime":1824.325,"body":"And of course, you know, what does pre-industrial mean even?"},{"startTime":1825.145,"endTime":1827.845,"body":"And again, I I'm not trying to send the message Oh, we dunno, anything."},{"startTime":1827.865,"endTime":1832.128,"body":"No, but I'm just pointing out that at, at the sort of 10th of a"},{"startTime":1832.128,"endTime":1832.412,"body":"degree level, you know, there is a certain amount of conventionality, should we say, at"},{"startTime":1832.412,"endTime":1837.245,"body":"least about this."},{"startTime":1837.305,"endTime":1841.576,"body":"You gotta kind of agree what pre-industrial means, because you could argue as long as"},{"startTime":1841.576,"endTime":1843.285,"body":"you liked about what is pre-industrial."},{"startTime":1843.425,"endTime":1847.28,"body":"And this is a, this is an estimate of global temperature going all the way"},{"startTime":1847.28,"endTime":1850.365,"body":"back to, um, you know, the, uh, naught of the common era."},{"startTime":1850.785,"endTime":1854.165,"body":"Um, and you can see that, you know, there was a gentle decline."},{"startTime":1854.305,"endTime":1858.715,"body":"And again, it's important to stress, you know, if buckets were an issue for this"},{"startTime":1858.715,"endTime":1859.01,"body":"part, when you go back beyond the, even the invention of the thermometer, you can"},{"startTime":1859.01,"endTime":1859.304,"body":"imagine the uncertainties in constructing a record of global temperature all the way back there"},{"startTime":1859.304,"endTime":1859.598,"body":"is, is, you know, there's all sorts of things get used, pollen, tree ring, ice"},{"startTime":1859.598,"endTime":1873.125,"body":"cores, and so on."},{"startTime":1873.305,"endTime":1875.485,"body":"But it's, it's a, it's a, it's an art."},{"startTime":1875.555,"endTime":1876.525,"body":"It's detective work."},{"startTime":1876.555,"endTime":1879.005,"body":"It's, it's, it's not something you've gone and actually measured."},{"startTime":1879.625,"endTime":1884.683,"body":"So, but it is believed that there's been this very gradual decline of a couple"},{"startTime":1884.683,"endTime":1889.405,"body":"of tenths of degree over the past thousand years, um, and indeed in this."},{"startTime":1889.625,"endTime":1895.011,"body":"So, so, you know, when you're choosing a period to regard as pre-industrial to measure"},{"startTime":1895.011,"endTime":1897.885,"body":"1.5 degrees against, you've gotta make a decision."},{"startTime":1898.065,"endTime":1904.125,"body":"Um, and they used this period in the late 19th century, um, 1850 to 1900."},{"startTime":1905.545,"endTime":1911.714,"body":"We actually had quite a lot of argument about that then, because, um, uh, the"},{"startTime":1911.714,"endTime":1912.125,"body":"physical climate scientists, um, people like myself, uh, preferred a a 20 year period, 1860"},{"startTime":1912.125,"endTime":1912.536,"body":"to 80, um, because it excluded, um, something very dramatic that happened in, uh, uh,"},{"startTime":1912.536,"endTime":1912.948,"body":"1883, which was the eruption of Mount Pin, uh, mount, sorry, Mount was, was the"},{"startTime":1912.948,"endTime":1931.045,"body":"recent one."},{"startTime":1931.385,"endTime":1936.925,"body":"Um, KRA tour was an even bigger eruption, which occurred, um, in, uh, 1883."},{"startTime":1937.265,"endTime":1943.585,"body":"Um, and an island in, in, uh, uh, uh, Indonesia blew up, um, and, um,"},{"startTime":1943.585,"endTime":1944.006,"body":"it's, uh, put so much, um, uh, material into the stratosphere, cooled the planet significantly,"},{"startTime":1944.006,"endTime":1955.805,"body":"and, uh, gave him lots of, um, material to Turner to paint his sunsets."},{"startTime":1955.805,"endTime":1959.885,"body":"These were the origins of the turner, those very dramatic sunsets, the turn us saw,"},{"startTime":1959.885,"endTime":1960.157,"body":"because this material passed all the way around the world and, and, and produced these"},{"startTime":1960.157,"endTime":1968.045,"body":"several years of very, very dramatic red sunsets, but also, you know, cool the planet."},{"startTime":1968.465,"endTime":1973.96,"body":"Um, and, um, uh, of course that, you know, should we include, um, uh, kra"},{"startTime":1973.96,"endTime":1976.525,"body":"guitar in the period that defined pre-industrial?"},{"startTime":1976.705,"endTime":1978.685,"body":"And we had a long, long arguments about this."},{"startTime":1979.005,"endTime":1979.805,"body":"I lost that argument."},{"startTime":1979.825,"endTime":1985.005,"body":"So it was included, um, and, uh, it, it didn't make that much difference."},{"startTime":1985.105,"endTime":1988.656,"body":"Um, but you, you can, you can see the sort of, you know, decisions that"},{"startTime":1988.656,"endTime":1988.893,"body":"have to be made here, uh, in, in, in, in defining where, where we're starting"},{"startTime":1988.893,"endTime":1992.445,"body":"from."},{"startTime":1993.265,"endTime":1996.93,"body":"But more importantly, you know, I promised, uh, I, I I promise we'd come back"},{"startTime":1996.93,"endTime":1997.175,"body":"to this about how, how, how it matters, how much it, how it matters, not"},{"startTime":1997.175,"endTime":2001.085,"body":"so much."},{"startTime":2002.545,"endTime":2006.832,"body":"Yes, it matters to lawyers when exactly we reach a 1.5 degrees, 'cause they're, you"},{"startTime":2006.832,"endTime":2009.405,"body":"know, they love to be pedantic about these things."},{"startTime":2009.625,"endTime":2015.49,"body":"But for the rest of us, um, what matters is, um, you know, how much"},{"startTime":2015.49,"endTime":2020.965,"body":"every incremental amount of warming we see is what, how much harm it's doing."},{"startTime":2021.545,"endTime":2026.896,"body":"And, and I, I talked about this, this backlash, um, that happened after the original,"},{"startTime":2026.896,"endTime":2027.253,"body":"uh, 1.5 degrees report landed, and we, we had all these headlines about 12 year"},{"startTime":2027.253,"endTime":2032.605,"body":"deadline."},{"startTime":2033.385,"endTime":2038.772,"body":"And, and Bjorn MBO indeed was tweeting this, um, with a, a figure showing, um,"},{"startTime":2038.772,"endTime":2042.005,"body":"estimates of damage as a function of global temperature."},{"startTime":2042.505,"endTime":2046.186,"body":"And one thing you'll notice is that, you know, he claims that, you know, three"},{"startTime":2046.186,"endTime":2046.432,"body":"degrees of warming is an income loss of about 3% of GDP, a couple of"},{"startTime":2046.432,"endTime":2050.605,"body":"years of growth."},{"startTime":2051.304,"endTime":2055.125,"body":"Um, now those numbers are highly contestable, and I'm gonna contest them in a minute."},{"startTime":2055.505,"endTime":2058.284,"body":"Um, but at least we can agree on the overall shape."},{"startTime":2058.665,"endTime":2062.945,"body":"So Bjorn  and I agree that the shape of this, of the damage function"},{"startTime":2062.945,"endTime":2066.085,"body":"is, you know, starts off really flat and then gets steeper."},{"startTime":2067.385,"endTime":2072.901,"body":"And that sort of makes sense because, um, as we move away from the familiar"},{"startTime":2072.901,"endTime":2073.269,"body":"climate that our ecosystems and our economy and so on have been adapted to, we"},{"startTime":2073.269,"endTime":2073.636,"body":"expect the impact of every additional 10th of a degree of warming to be worse"},{"startTime":2073.636,"endTime":2085.405,"body":"than the last one."},{"startTime":2086.145,"endTime":2087.125,"body":"Why do we expect that?"},{"startTime":2087.514,"endTime":2092.292,"body":"Because just ask yourself what would happen if we went away in the other direction"},{"startTime":2092.292,"endTime":2093.885,"body":"that would also cause harm?"},{"startTime":2094.225,"endTime":2099.085,"body":"You know, cooling the planet would, would cause harm because we're adapted to that."},{"startTime":2099.705,"endTime":2106.14,"body":"Um, we're adapted to that, um, uh, point in the middle where, uh, where, uh,"},{"startTime":2106.14,"endTime":2108.285,"body":"civilization, if you like, developed."},{"startTime":2109.625,"endTime":2113.656,"body":"Um, and so the simplest shape we could adopt, um, is what we call a"},{"startTime":2113.656,"endTime":2113.925,"body":"quadratic."},{"startTime":2113.985,"endTime":2116.885,"body":"That's a sort of a, a, a temperature squared curve."},{"startTime":2117.475,"endTime":2117.765,"body":"Okay?"},{"startTime":2118.105,"endTime":2122.655,"body":"And, and, um, again, uh, physicists love to do this kind of thing on a"},{"startTime":2122.655,"endTime":2123.565,"body":"small enough scale."},{"startTime":2123.565,"endTime":2126.125,"body":"Everything's a quadratic if it's not a straight line."},{"startTime":2126.275,"endTime":2131.353,"body":"Yeah, I mean, uh, so, and, uh, uh, if you, okay, sorry, in, in, in"},{"startTime":2131.353,"endTime":2131.691,"body":"jokes I suppose, but anyway, um, but the point is therefore, you know, for small"},{"startTime":2131.691,"endTime":2132.03,"body":"enough warming, um, you are, you are sort of ex you should expect to see"},{"startTime":2132.03,"endTime":2132.368,"body":"this kind of shape, which means that if, you know, according to lomborg, beyond Lomborg,"},{"startTime":2132.368,"endTime":2132.707,"body":"um, a three degrees of warming costs two to 4% of GDP, then six degrees"},{"startTime":2132.707,"endTime":2156.405,"body":"of warming would cause, uh, a loss of, you know, around 10% of GDP."},{"startTime":2157.025,"endTime":2162.315,"body":"And of course, you know, con con, conversely, as you go to the other side,"},{"startTime":2162.315,"endTime":2167.605,"body":"um, uh, six degrees of cooling should cost sort of eight to 10% of GDP."},{"startTime":2168.275,"endTime":2171.756,"body":"Well, I don't know, but I think six degrees of cooling would probably cost a"},{"startTime":2171.756,"endTime":2173.845,"body":"little bit more than 10% of gross domestic products."},{"startTime":2173.845,"endTime":2177.895,"body":"You know, we, we have experienced that in the past and, um, it sucked, um,"},{"startTime":2177.895,"endTime":2180.325,"body":"for the humans that were around at the time."},{"startTime":2180.785,"endTime":2182.165,"body":"So in fact, we've done quite a lot of work."},{"startTime":2182.165,"endTime":2187.722,"body":"One of the things we did for the 1.5 degrees report was in fact, um,"},{"startTime":2187.722,"endTime":2188.093,"body":"a, a study of the economic impact of, uh, 1.5 degrees of warming versus two"},{"startTime":2188.093,"endTime":2188.463,"body":"degrees, uh, versus the present day and versus two degrees, um, using not the kind"},{"startTime":2188.463,"endTime":2188.834,"body":"of back of the envelope on the estimates that Bjorn MBO was using, but actually"},{"startTime":2188.834,"endTime":2189.204,"body":"using data of how growth, uh, observed growth in the economies of different countries responds"},{"startTime":2189.204,"endTime":2211.805,"body":"to variations in global temperature."},{"startTime":2211.805,"endTime":2213.765,"body":"And Felix Preiss led this study."},{"startTime":2213.945,"endTime":2217.666,"body":"Um, it was a very elaborate, uh, statistical study because of course he had to"},{"startTime":2217.666,"endTime":2217.914,"body":"take into account all the other things that were going on, like wars and, you"},{"startTime":2217.914,"endTime":2223.125,"body":"know, global economic growth and so on."},{"startTime":2223.385,"endTime":2226.554,"body":"Um, and, um, but he, you know, he was able to tease out a temperature"},{"startTime":2226.554,"endTime":2228.245,"body":"impact with a lot of uncertainty in it."},{"startTime":2228.315,"endTime":2229.405,"body":"It's important distress."},{"startTime":2229.705,"endTime":2235.187,"body":"So there's large uncertainty bars there, but he was able to identify not just, um,"},{"startTime":2235.187,"endTime":2235.553,"body":"the global impact of, uh, a further, uh, half a degree of warming above where"},{"startTime":2235.553,"endTime":2235.919,"body":"we'd reached, but also, um, the impact on different, how, how this affects different countries,"},{"startTime":2235.919,"endTime":2246.885,"body":"uh, individually."},{"startTime":2247.545,"endTime":2251.372,"body":"Um, and as we go to two degrees, you can see all the purple countries"},{"startTime":2251.372,"endTime":2251.627,"body":"here are the ones that are being adversely affected by two degrees of warming relative"},{"startTime":2251.627,"endTime":2255.965,"body":"to the present."},{"startTime":2256.305,"endTime":2257.605,"body":"And you can see where they all are."},{"startTime":2257.675,"endTime":2258.645,"body":"Predictably enough."},{"startTime":2258.645,"endTime":2260.885,"body":"These are the big countries in the tro."},{"startTime":2261.055,"endTime":2265.245,"body":"These are countries in the tropics that are vulnerable to a little bit more additional"},{"startTime":2265.245,"endTime":2265.525,"body":"warming."},{"startTime":2265.685,"endTime":2269.782,"body":"'cause a lot of, you know, they're, they're, they're, they're sensitive to, um, uh, uh,"},{"startTime":2269.782,"endTime":2270.055,"body":"uh, uh, the, the heat stress, the, the, the and, and the additional, um, in"},{"startTime":2270.055,"endTime":2276.885,"body":"burden on their economies that will result from, from any warming."},{"startTime":2276.885,"endTime":2279.205,"body":"You'll notice a couple of green countries are appearing here."},{"startTime":2279.335,"endTime":2283.263,"body":"These are countries who, according to the data, this was just a purely data driven"},{"startTime":2283.263,"endTime":2283.525,"body":"study."},{"startTime":2284.185,"endTime":2286.325,"body":"And, you know, there's a bit of squeamishness about this."},{"startTime":2286.325,"endTime":2287.805,"body":"We said, no, no, we published the results."},{"startTime":2288.025,"endTime":2293.234,"body":"And these are countries where, um, according to the data, there would be a small"},{"startTime":2293.234,"endTime":2293.581,"body":"benefit, um, from a, a, uh, a, uh, a further, um, uh, degree of warming"},{"startTime":2293.581,"endTime":2299.485,"body":"above the present."},{"startTime":2299.945,"endTime":2305.741,"body":"Um, and we could also show who benefited and who lost out from limiting warming"},{"startTime":2305.741,"endTime":2309.605,"body":"to 1.5 degrees versus allowing it to go to two."},{"startTime":2309.945,"endTime":2315.762,"body":"And the key point here was that nobody benefited significantly from allowing temperatures to go"},{"startTime":2315.762,"endTime":2320.805,"body":"above 1.5, uh, to two, but several countries significantly lost out from that."},{"startTime":2320.945,"endTime":2323.765,"body":"And we could, you know, able to sort of identify these countries."},{"startTime":2323.765,"endTime":2324.765,"body":"And there's a big table of them."},{"startTime":2324.945,"endTime":2328.967,"body":"And the ones at the bottom of the table, just to sort of illustrate the"},{"startTime":2328.967,"endTime":2329.235,"body":"countries that are most vulnerable to this additional warming are, you know, Saudi Arabia, Mauritania,"},{"startTime":2329.235,"endTime":2329.504,"body":"Djibouti, Bangladesh, Saudi, you may be slightly surprised to see Saudi Arabia on that list,"},{"startTime":2329.504,"endTime":2329.772,"body":"but of course, this is about the impacts of the warming, not the impacts of"},{"startTime":2329.772,"endTime":2342.645,"body":"the process that causes the warming."},{"startTime":2342.745,"endTime":2346.985,"body":"So, you know, um, and, uh, and up at the top, you know, cold countries"},{"startTime":2346.985,"endTime":2348.965,"body":"like Russia, Canada, Mongolia, and so on."},{"startTime":2349.065,"endTime":2353.984,"body":"So, so the, one of the key things which comes outta this of course, is"},{"startTime":2353.984,"endTime":2354.311,"body":"that the impacts of warming are very, very different depending on, um, which, uh, uh,"},{"startTime":2354.311,"endTime":2354.639,"body":"which, uh, country you're in or sort of what your, what your position is, you"},{"startTime":2354.639,"endTime":2354.967,"body":"know, and how much warming costs you depends very much on who you are and"},{"startTime":2354.967,"endTime":2369.725,"body":"where you live."},{"startTime":2370.585,"endTime":2375.995,"body":"Um, which is why in 2018, we said very firmly that one of the questions"},{"startTime":2375.995,"endTime":2380.685,"body":"that we were being asked by the governments, we refused to answer it."},{"startTime":2380.685,"endTime":2384.845,"body":"They were basically asking us, is it worth it limiting warming to 1.5 degrees?"},{"startTime":2384.865,"endTime":2389.597,"body":"And we said, any comparison between one and a half and higher levels of warming"},{"startTime":2389.597,"endTime":2389.912,"body":"implies a risk assessment and value judgements that we can't reduce to a cost benefit"},{"startTime":2389.912,"endTime":2394.645,"body":"analysis."},{"startTime":2394.645,"endTime":2398.025,"body":"This is the kind of kind of thing that the treasury loves to do, comparing"},{"startTime":2398.025,"endTime":2401.405,"body":"cost of a policy with benefits of it and working out if it's worth it."},{"startTime":2401.945,"endTime":2406.498,"body":"Um, interestingly, in 2023, the intergovernmental panel on climate change really stuck its neck out"},{"startTime":2406.498,"endTime":2406.801,"body":"on this, um, and actually said the global economic and social benefits of limiting global"},{"startTime":2406.801,"endTime":2415.605,"body":"warming to two degrees exceed the cost of mitigation in most of the assessed literature."},{"startTime":2416.345,"endTime":2421.279,"body":"Um, but um, they, uh, they, so they, they, um, and the, the reason I,"},{"startTime":2421.279,"endTime":2421.608,"body":"I was very surprised to see that statement, um, in the, the, um, sixth assessment"},{"startTime":2421.608,"endTime":2421.937,"body":"report, which came out a couple of years ago, was they don't make the same"},{"startTime":2421.937,"endTime":2422.266,"body":"statement about 1.5 degrees, um, because they, and, and so, so they were implicitly acknowledging,"},{"startTime":2422.266,"endTime":2422.595,"body":"they actually have a footnote that explicitly acknowledges that they can't make the same claim"},{"startTime":2422.595,"endTime":2442.005,"body":"about 1.5 degrees."},{"startTime":2442.065,"endTime":2445.41,"body":"So, so does that mean, and it sort of, someone could read this, oh, well,"},{"startTime":2445.41,"endTime":2446.525,"body":"it's not even worth it."},{"startTime":2446.635,"endTime":2452.485,"body":"It's, it's economically, it's, it's not worth even trying to limit warming to 1.5 degrees."},{"startTime":2453.865,"endTime":2461.093,"body":"So, but I mean, the, the, the, the crucial issue that, that you, that, that"},{"startTime":2461.093,"endTime":2461.575,"body":"I, you know, that that emerges here, is that how much globally you regard a"},{"startTime":2461.575,"endTime":2462.057,"body":"warming of two degrees versus 1.5 degrees to cost depends critically on how much you"},{"startTime":2462.057,"endTime":2479.405,"body":"weight impacts on Congo to impacts on Canada."},{"startTime":2480.825,"endTime":2486.562,"body":"And if you just add up dollar impacts, you often find the impacts on Canada"},{"startTime":2486.562,"endTime":2490.005,"body":"are much more valuable than the impacts on Congo."},{"startTime":2490.125,"endTime":2491.405,"body":"'cause Congo didn't have much money in the first place."},{"startTime":2491.425,"endTime":2495.341,"body":"So, you know, you take 10% off their economy while it was wasn't great in"},{"startTime":2495.341,"endTime":2496.125,"body":"the first place."},{"startTime":2496.225,"endTime":2497.765,"body":"So it's not very much money in the end."},{"startTime":2497.795,"endTime":2502.251,"body":"Whereas, you know, a couple of percent benefit to Canada is, is a big impact"},{"startTime":2502.251,"endTime":2504.925,"body":"on global GDP, but clearly thank you very much."},{"startTime":2504.925,"endTime":2505.485,"body":"That's great."},{"startTime":2506.145,"endTime":2511.349,"body":"Um, and, uh, um, one of the, one of the crucial things which comes out"},{"startTime":2511.349,"endTime":2514.125,"body":"in this is that climate change costs lives."},{"startTime":2515.065,"endTime":2519.493,"body":"And if you, um, if you want to add up the cost of climate change"},{"startTime":2519.493,"endTime":2519.789,"body":"you need, you may, you may not be explicit about it, but you need implicitly"},{"startTime":2519.789,"endTime":2526.285,"body":"to assign a statistical value to a life."},{"startTime":2527.545,"endTime":2532.358,"body":"And back in 1995, the intergovernmental plan on plan on climate change actually did this"},{"startTime":2532.358,"endTime":2534.605,"body":"exercise, the sort of cost benefit analysis."},{"startTime":2534.985,"endTime":2539.055,"body":"And they did what was standard at the time, which was you assign a value"},{"startTime":2539.055,"endTime":2543.125,"body":"to a life according to what somebody is willing to pay to prolong their life."},{"startTime":2544.145,"endTime":2546.485,"body":"And you look at the statistics of different countries and work it out."},{"startTime":2547.705,"endTime":2549.805,"body":"But of course, that's not a function of what the life's worth."},{"startTime":2549.915,"endTime":2553.125,"body":"It's what it's, it's a function of what the person's able to pay."},{"startTime":2553.785,"endTime":2558.308,"body":"And as a result, it sort of emerged in the course of producing the 1995"},{"startTime":2558.308,"endTime":2558.61,"body":"report, that they were effectively waiting the life of a Bangladeshi at some tiny fraction"},{"startTime":2558.61,"endTime":2565.245,"body":"of the life of a resident of Florida."},{"startTime":2565.625,"endTime":2570.08,"body":"And there was a huge row, and that entire section of the report got ditched,"},{"startTime":2570.08,"endTime":2571.565,"body":"um, I think rightly so."},{"startTime":2571.985,"endTime":2577.097,"body":"Um, and the IPCC, the Intermental Panel on Climate Change has been, you know, very"},{"startTime":2577.097,"endTime":2580.165,"body":"squeamish about coming back into that arena ever since."},{"startTime":2580.185,"endTime":2584.026,"body":"And I think, I think correctly, so, so I was very surprised when they ventured"},{"startTime":2584.026,"endTime":2584.282,"body":"back into this in the, in the last report, you'll notice that their, their, their"},{"startTime":2584.282,"endTime":2584.538,"body":"comment is not about a judgment of the IPCC, it's just a comment about the"},{"startTime":2584.538,"endTime":2591.965,"body":"literature."},{"startTime":2592.385,"endTime":2596.945,"body":"And so it's, it's it, you know, it's appropriately cautious, but I, you know, it's,"},{"startTime":2596.945,"endTime":2597.25,"body":"it's, um, it's a, it's a problem, um, trying to assign value to different levels"},{"startTime":2597.25,"endTime":2597.554,"body":"of warming in the way that people like Gil Mbo and the sort of a"},{"startTime":2597.554,"endTime":2597.858,"body":"lot of the community saying, you know, it's not really worth it trying to do"},{"startTime":2597.858,"endTime":2611.845,"body":"anything about climate change."},{"startTime":2612.045,"endTime":2614.205,"body":"'cause let's face it, it's not gonna do very much harm anyway."},{"startTime":2614.705,"endTime":2619.996,"body":"The way in order to say how much harm climate change is doing, they have"},{"startTime":2619.996,"endTime":2620.349,"body":"to add up impacts in this way, and they have to make decisions about things"},{"startTime":2620.349,"endTime":2627.405,"body":"like the statistical value of life."},{"startTime":2627.505,"endTime":2629.685,"body":"Are poor lives worth less than rich ones."},{"startTime":2630.145,"endTime":2634.909,"body":"Um, you know, social impacts a mass movement of people from a part of the"},{"startTime":2634.909,"endTime":2635.226,"body":"world made uninhabitable by rising temperatures, which might be a poor part of the world"},{"startTime":2635.226,"endTime":2643.485,"body":"to a rich part of the world would probably increase global GDP."},{"startTime":2644.515,"endTime":2649.09,"body":"Yeah, once everybody moved, they then sort of get much closer to automatically get much"},{"startTime":2649.09,"endTime":2652.445,"body":"closer to the income levels of the country of their destination."},{"startTime":2653.145,"endTime":2656.965,"body":"Um, and o on average, the world would be richer."},{"startTime":2657.185,"endTime":2661.125,"body":"But you can just imagine the social disruption that might accompany that."},{"startTime":2661.905,"endTime":2665.245,"body":"Um, anybody listening who's worried about small boats?"},{"startTime":2665.245,"endTime":2665.805,"body":"There you go."},{"startTime":2666.285,"endTime":2671.045,"body":"I mean, it's, it's, it's, these are not cost-free disruptions."},{"startTime":2671.985,"endTime":2676.861,"body":"Um, and also there's, you know, for for, for, for the Stratham College of Stratham"},{"startTime":2676.861,"endTime":2677.186,"body":"School kids, there's a, a very important part of this, of course, is how do"},{"startTime":2677.186,"endTime":2685.965,"body":"we wait impacts on the present day generation to impact on future generations?"},{"startTime":2686.225,"endTime":2691.04,"body":"Um, and again, that's crucial element in, in, in deciding what the value is of"},{"startTime":2691.04,"endTime":2692.325,"body":"different levels of warming."},{"startTime":2692.865,"endTime":2698.786,"body":"So what I think we can't do this, um, assigning an an absolute value, um,"},{"startTime":2698.786,"endTime":2700.365,"body":"to global climate change."},{"startTime":2700.705,"endTime":2705.205,"body":"Um, what we can do is say that it's roughly that shape."},{"startTime":2706.085,"endTime":2709.005,"body":"I think that's pretty safe 'cause everybody agrees on that."},{"startTime":2709.665,"endTime":2714.496,"body":"And in a sense it sort of almost has to be if we just accept"},{"startTime":2714.496,"endTime":2714.819,"body":"that that was the climate we were adjusted to, we expect climate damage to get"},{"startTime":2714.819,"endTime":2715.141,"body":"worse and get worse faster as we move away from that, um, from that pre-industrial,"},{"startTime":2715.141,"endTime":2724.805,"body":"uh, condition."},{"startTime":2724.805,"endTime":2731.285,"body":"So whatever damage climate change is causing today, we could expect two degrees of warming."},{"startTime":2731.655,"endTime":2733.725,"body":"We're at one and a quarter degree now."},{"startTime":2733.825,"endTime":2737.608,"body":"So we, the damage we've experienced over the past decade is around sort of like"},{"startTime":2737.608,"endTime":2738.365,"body":"one degree damage."},{"startTime":2738.995,"endTime":2739.285,"body":"Okay?"},{"startTime":2739.465,"endTime":2744.635,"body":"So we could expect, um, at two degrees, four times as much damage just square"},{"startTime":2744.635,"endTime":2745.325,"body":"the temperature."},{"startTime":2745.595,"endTime":2750.181,"body":"Yeah, one and a one and a half degrees, two and a quarter times the"},{"startTime":2750.181,"endTime":2751.405,"body":"most damage, slightly harder."},{"startTime":2751.405,"endTime":2752.685,"body":"Some, you can probably still do it in your head."},{"startTime":2753.065,"endTime":2758.588,"body":"Um, one and a quarter degrees where we're at now, 1.6 times, uh, the, the,"},{"startTime":2758.588,"endTime":2759.325,"body":"the damage."},{"startTime":2759.905,"endTime":2764.978,"body":"So what this tells you is, you know, you don't have to agree with anybody"},{"startTime":2764.978,"endTime":2765.316,"body":"about the absolute value of the damage, but the difference between 1.5 degrees and two"},{"startTime":2765.316,"endTime":2765.654,"body":"degrees, that additional half a degree of warming is going to do as least as"},{"startTime":2765.654,"endTime":2778.845,"body":"much damage as all the climate changes has happened to date."},{"startTime":2780.525,"endTime":2785.1,"body":"Because we expect the damage to get steeper, the damage curve to get steeper as"},{"startTime":2785.1,"endTime":2786.015,"body":"we move ahead."},{"startTime":2786.595,"endTime":2789.895,"body":"So that allows you to put it into context."},{"startTime":2790.995,"endTime":2795.853,"body":"Um, and, you know, whatever you care about climate and what's happened already, you should"},{"startTime":2795.853,"endTime":2796.177,"body":"care just that much and more about avoiding that additional half a degree of warming"},{"startTime":2796.177,"endTime":2802.655,"body":"beyond one and a half degrees."},{"startTime":2803.955,"endTime":2808.474,"body":"So I just wanna wrap up by talking about briefly about how not to think"},{"startTime":2808.474,"endTime":2808.775,"body":"about warming, um, by 2100 because you're gonna hear lots of headlines about this during"},{"startTime":2808.775,"endTime":2813.295,"body":"cop."},{"startTime":2813.795,"endTime":2819.09,"body":"Um, this thermometer is a very, um, um, uh, beloved, uh, graphic that is flashed"},{"startTime":2819.09,"endTime":2820.855,"body":"around a lot at cop."},{"startTime":2821.235,"endTime":2827.789,"body":"Um, it's massively misleading, um, because it implies that, um, you know, it basically what"},{"startTime":2827.789,"endTime":2828.226,"body":"it's about is warming to 2100 and it tells you that, you know, if we,"},{"startTime":2828.226,"endTime":2840.025,"body":"uh, if we manage our 2030 targets, we'll limit warming to 2.4 degrees."},{"startTime":2841.005,"endTime":2845.355,"body":"Um, and if we go, you know, much beyond that and include all the long-term"},{"startTime":2845.355,"endTime":2847.385,"body":"pledges, we'll limit warming to two degrees."},{"startTime":2847.885,"endTime":2851.414,"body":"So you might think, well, that's a lot of work, work for 0.4 of a"},{"startTime":2851.414,"endTime":2851.885,"body":"degree, okay?"},{"startTime":2852.345,"endTime":2858.527,"body":"Um, and um, what this is doing is actually le leaving out the crucial points"},{"startTime":2858.527,"endTime":2863.885,"body":"that what the numbers here they're talking about are only warming by 2100."},{"startTime":2863.885,"endTime":2870.835,"body":"They're not actually differentiating between, you know, conditions where we've actually stopped the warming in"},{"startTime":2870.835,"endTime":2875.005,"body":"2100 or situations where it's still carrying on warming."},{"startTime":2875.905,"endTime":2881.574,"body":"And this, even this fixation on 2100 even started to creep into the negotiations in,"},{"startTime":2881.574,"endTime":2881.952,"body":"in Glasgow where, um, we, we, they, they started talking about limiting warming to 1.5"},{"startTime":2881.952,"endTime":2890.645,"body":"degrees by 2100 as if that was the goal."},{"startTime":2891.665,"endTime":2896.231,"body":"Um, and of course, if you, if that were the goal, and it certainly wasn't"},{"startTime":2896.231,"endTime":2896.535,"body":"the goal agreed in Paris, um, you would never, you then would never know whether"},{"startTime":2896.535,"endTime":2896.84,"body":"you'd met it or not until into 2020 second century as if the goal was"},{"startTime":2896.84,"endTime":2907.495,"body":"limiting warming to 1.5 degrees by 2100."},{"startTime":2907.795,"endTime":2911.175,"body":"You wouldn't know until 2010 whether you'd succeeded or not, 2110."},{"startTime":2911.515,"endTime":2913.815,"body":"And, and, and, and whether you, whether you succeeded or not."},{"startTime":2914.115,"endTime":2916.719,"body":"So, you know, this obviously would have huge ramifications for things like loss and damage"},{"startTime":2916.719,"endTime":2916.892,"body":"because then people would say, well, you know, we don't dunno if we made it"},{"startTime":2916.892,"endTime":2917.066,"body":"or not, you know, even though temperatures are at, might be at two and a"},{"startTime":2917.066,"endTime":2917.24,"body":"half degrees, but, you know, we may be, you know, on our way back down"},{"startTime":2917.24,"endTime":2926.615,"body":"to one and a half degrees by two nine or two nos."},{"startTime":2926.995,"endTime":2931.645,"body":"Um, so, so that's, you know, fortunately in, in that was got rid of very"},{"startTime":2931.645,"endTime":2933.815,"body":"quickly, um, from the draft decision text."},{"startTime":2934.035,"endTime":2939.452,"body":"Um, and, uh, um, but it, this, this way of thinking is, um, is hasn't"},{"startTime":2939.452,"endTime":2940.175,"body":"gone away."},{"startTime":2940.835,"endTime":2946.242,"body":"Um, in the press press release that accompanied the UNAP gap report, um, that landed"},{"startTime":2946.242,"endTime":2946.603,"body":"this morning, we see this, um, current targets basically would lead to temperatures not exceeding"},{"startTime":2946.603,"endTime":2954.535,"body":"two and a half degrees above pre-industrial levels."},{"startTime":2955.475,"endTime":2961.166,"body":"Now, current targets would return the current rate of warming from roughly quarter of a"},{"startTime":2961.166,"endTime":2961.545,"body":"degree per decade, which is at the moment to about one, uh, one point, uh,"},{"startTime":2961.545,"endTime":2968.375,"body":"0.17 degrees per decade."},{"startTime":2968.835,"endTime":2970.695,"body":"So reduce it by about a third or so."},{"startTime":2971.595,"endTime":2974.673,"body":"Um, and then if you work it out, that gets you to two and a"},{"startTime":2974.673,"endTime":2975.495,"body":"half degrees by 2100."},{"startTime":2975.515,"endTime":2980.225,"body":"So it lowers the rate of warming slightly, but it's still warming."},{"startTime":2981.125,"endTime":2983.865,"body":"So it doesn't limit warming to two and a half degrees at all."},{"startTime":2984.605,"endTime":2988.85,"body":"It just means, you know, instead of getting 2.7 degrees by carrying on the current"},{"startTime":2988.85,"endTime":2990.265,"body":"rate, you at 2.5 degrees."},{"startTime":2990.885,"endTime":2994.08,"body":"Um, so it's a, and, and, and, you know, they didn't, they in the press"},{"startTime":2994.08,"endTime":2995.785,"body":"release, they didn't even mention 2100 at all."},{"startTime":2995.805,"endTime":2998.145,"body":"So this is very dangerous rhetoric, okay?"},{"startTime":2998.935,"endTime":3000.985,"body":"Back to what 1.5 degrees actually means."},{"startTime":3001.645,"endTime":3005.948,"body":"Um, you know, the right way to think about it is there's a lot of"},{"startTime":3005.948,"endTime":3006.235,"body":"sort of bogus precision banded around at these cops, you know, 2.7 degrees versus 2.4"},{"startTime":3006.235,"endTime":3010.825,"body":"degrees, really?"},{"startTime":3010.895,"endTime":3011.985,"body":"Yeah, we, we don't know these."},{"startTime":3012.365,"endTime":3015.905,"body":"So you mustn't let yourself be distracted by this bogus precision."},{"startTime":3016.245,"endTime":3018.025,"body":"1.5 degrees is a milestone."},{"startTime":3018.525,"endTime":3021.737,"body":"Um, it's important when we pass a milestone to note that we, if we do"},{"startTime":3021.737,"endTime":3023.665,"body":"pass the milestone, we hope we won't pass it."},{"startTime":3024.005,"endTime":3028.09,"body":"Um, but if we do pass the milestone, you shouldn't expect anything dramatic to happen"},{"startTime":3028.09,"endTime":3029.725,"body":"just because you passed the milestone."},{"startTime":3030.265,"endTime":3032.365,"body":"Um, but it does tell you the direction of travel."},{"startTime":3032.905,"endTime":3035.982,"body":"Um, and indeed, you know, it's, it's actually quite a good analogy, the sort of"},{"startTime":3035.982,"endTime":3038.445,"body":"24 miles to London, what does it mean 24 miles to London?"},{"startTime":3038.605,"endTime":3042.645,"body":"I mean, London's, you know, however many miles across, so you have to choose rather"},{"startTime":3042.645,"endTime":3046.685,"body":"specifically one bit of London as you know, the place you're gonna measure stuff from."},{"startTime":3046.955,"endTime":3048.205,"body":"It's chaing cross or something, isn't it?"},{"startTime":3048.205,"endTime":3051.365,"body":"I I, I can't remember Anyway, but, but the point is, it's a convention."},{"startTime":3051.825,"endTime":3054.245,"body":"Um, and, and the same goes really for global temperature."},{"startTime":3054.245,"endTime":3059.763,"body":"We have to, we had to sort of agree what pre-industrial was, and so therefore,"},{"startTime":3059.763,"endTime":3060.131,"body":"you know, there's no sort of nothing absolute that's gonna happen, but just to, you"},{"startTime":3060.131,"endTime":3060.499,"body":"know, remember you, you know, as, as we approach, uh, this cop, remember this, uh,"},{"startTime":3060.499,"endTime":3060.867,"body":"analogy that I gave you early on in these lectures, um, if we hit the"},{"startTime":3060.867,"endTime":3061.235,"body":"brakes now, um, and managed to stop warming by mid-century, we would limit future warming,"},{"startTime":3061.235,"endTime":3085.885,"body":"all future warming to less than what's already happened this century."},{"startTime":3087.285,"endTime":3090.795,"body":"I think, you know, if you remember that, that's, you know, that's not, doesn't mean"},{"startTime":3090.795,"endTime":3091.965,"body":"it's not a big deal."},{"startTime":3092.385,"endTime":3095.88,"body":"Adding on the same amount of warming again that we've already had since 2000 will"},{"startTime":3095.88,"endTime":3097.045,"body":"cause a lot of harm."},{"startTime":3098.705,"endTime":3101.745,"body":"But if we manage to do that, we'll avoid a lot of harm as well,"},{"startTime":3101.745,"endTime":3103.165,"body":"and that would be a huge result."},{"startTime":3104.145,"endTime":3109.564,"body":"And, you know, I think we, um, need that, which is why this coming cop"},{"startTime":3109.564,"endTime":3109.925,"body":"in Dubai is so important because we are finally starting to talk about the kind"},{"startTime":3109.925,"endTime":3110.286,"body":"of things we need to do to actually stop fossil fuels from causing global warming"},{"startTime":3110.286,"endTime":3121.125,"body":"by mid-century."},{"startTime":3121.625,"endTime":3125.205,"body":"So things to look for in the outcome of Cop 28."},{"startTime":3125.745,"endTime":3130.788,"body":"Um, will we agree to phase out all unabated use of fossil fuels at this"},{"startTime":3130.788,"endTime":3131.125,"body":"cop?"},{"startTime":3131.635,"endTime":3135.445,"body":"What, you know, that's what, that's the phrase to look for in the findings."},{"startTime":3136.035,"endTime":3139.906,"body":"Then of course, we've gotta agree on what abated use means, and we better agree"},{"startTime":3139.906,"endTime":3140.164,"body":"that it means something that's compatible with the Paris Agreement, meaning permanent storage of all"},{"startTime":3140.164,"endTime":3140.422,"body":"the CO2 generated, and then of course, we've gotta get on with it and phase"},{"startTime":3140.422,"endTime":3151.005,"body":"up the fraction of carbon dioxide that is safely and permanently disposed of."},{"startTime":3151.465,"endTime":3155.885,"body":"Um, at the same time as we phase down total fossil fuel use."},{"startTime":3156.465,"endTime":3160.551,"body":"And this is one sort of good bit of news, um, coming out of this"},{"startTime":3160.551,"endTime":3164.365,"body":"cop because it's really important to emphasize the positives, uh, in the climate issue."},{"startTime":3164.785,"endTime":3170.948,"body":"Um, there is a little reported, um, development led by, um, uh, motley crew, including"},{"startTime":3170.948,"endTime":3171.358,"body":"the United States, Saudi Arabia, Canada, the United Kingdom even, um, which is committing to"},{"startTime":3171.358,"endTime":3171.769,"body":"store a million, a billion tons of carbon dioxide back into the Earth's crust by"},{"startTime":3171.769,"endTime":3183.685,"body":"2030."},{"startTime":3183.685,"endTime":3185.565,"body":"They're calling it the Carbon Management Challenge."},{"startTime":3186.265,"endTime":3191.756,"body":"And if you work out what this means, if they can maintain that rate of"},{"startTime":3191.756,"endTime":3192.122,"body":"acceleration in driving up the fraction of carbon dioxide generated by the fossil fuels we"},{"startTime":3192.122,"endTime":3199.445,"body":"use, um, that's re-injected back underground."},{"startTime":3199.505,"endTime":3203.394,"body":"If they can maintain that over the next 30 years, then we'll stop fossil fuels"},{"startTime":3203.394,"endTime":3206.765,"body":"from causing global warming by the 2050s, which would be a huge result."},{"startTime":3207.105,"endTime":3210.875,"body":"Um, and let's, so let's watch, watch for that language and watch for the Carbon"},{"startTime":3210.875,"endTime":3211.126,"body":"Management Challenge and watch for the countries that are joining in with it, where they're"},{"startTime":3211.126,"endTime":3216.405,"body":"actually putting action where their words are."},{"startTime":3216.585,"endTime":3221.432,"body":"Anyway, to sum up, y 1.5 degree map, every 10th of degree causes more harm"},{"startTime":3221.432,"endTime":3222.725,"body":"than the last one."},{"startTime":3223.425,"endTime":3227.7,"body":"Um, warming, remember this, you know, when people are saying warming from 1.5 degrees is,"},{"startTime":3227.7,"endTime":3229.125,"body":"is is not that harmful?"},{"startTime":3229.195,"endTime":3233.259,"body":"Well, warming from 1.5 degrees to two degrees is at least as harmful as the"},{"startTime":3233.259,"endTime":3234.885,"body":"warming we've already experienced to date."},{"startTime":3235.585,"endTime":3237.525,"body":"Um, but it is a milestone, not a cliff edge."},{"startTime":3237.945,"endTime":3242.088,"body":"Um, we, there's no reason to to believe that anything dramatic will happen when we"},{"startTime":3242.088,"endTime":3242.364,"body":"get to 1.5 degrees, but it is the point at which we have agreed collectively"},{"startTime":3242.364,"endTime":3248.165,"body":"that we're gonna try and limit warming."},{"startTime":3248.225,"endTime":3252.361,"body":"So let's hope for a good outcome at Cop, uh, 28, um, and get us"},{"startTime":3252.361,"endTime":3252.637,"body":"on the road to, um, achieving that m uh, to, to stopping before we get"},{"startTime":3252.637,"endTime":3257.325,"body":"to that milestone."},{"startTime":3257.325,"endTime":3257.685,"body":"Thank you."},{"startTime":3257.935,"endTime":3260.358,"body":"Sorry, I've got a bit close to time, but hopefully we've got enough time for"},{"startTime":3260.358,"endTime":3261.005,"body":"a couple of questions."},{"startTime":3261.215,"endTime":3261.645,"body":"Thank you,"},{"startTime":3269.635,"endTime":3270.405,"body":"Professor Allen."},{"startTime":3270.405,"endTime":3270.805,"body":"Thank you."},{"startTime":3270.805,"endTime":3272.285,"body":"That was a fascinating lecture."},{"startTime":3272.385,"endTime":3276.002,"body":"And yes, I think we will squeeze in a couple of questions if we, if"},{"startTime":3276.002,"endTime":3276.485,"body":"we can."},{"startTime":3276.705,"endTime":3280.48,"body":"Um, so the first one, uh, there's quite a few, um, 'cause a lot of"},{"startTime":3280.48,"endTime":3284.005,"body":"the lecture covered elements of methods like how you come to these, these decisions."},{"startTime":3284.465,"endTime":3288.325,"body":"And so there's a few, I'm gonna sort of bunch them into one another."},{"startTime":3288.355,"endTime":3288.925,"body":"I'll have a go."},{"startTime":3289.265,"endTime":3293.298,"body":"Um, so when you sort of, as you talked about with the economics, it was"},{"startTime":3293.298,"endTime":3296.525,"body":"striking how you use a different model, a different baseline for calculation."},{"startTime":3296.525,"endTime":3299.645,"body":"You get quite wildly different models, which then produces very different results."},{"startTime":3299.985,"endTime":3303.304,"body":"But thinking about the science, when you said, you know, you were the first sort"},{"startTime":3303.304,"endTime":3303.525,"body":"of group of people that sat down and taught about 1.5, how do you start"},{"startTime":3303.525,"endTime":3306.845,"body":"that?"},{"startTime":3306.905,"endTime":3310.223,"body":"How do you go about getting, because science by its nature, it's all committed to"},{"startTime":3310.223,"endTime":3310.445,"body":"truthfulness."},{"startTime":3310.665,"endTime":3312.365,"body":"We, we hope, um, we know."},{"startTime":3312.665,"endTime":3317.222,"body":"But, um, but so many different disparate sources, how do you bring them together into"},{"startTime":3317.222,"endTime":3320.565,"body":"any sort of a, a unity to, to, to calculate from?"},{"startTime":3320.675,"endTime":3320.965,"body":"Yeah,"},{"startTime":3320.965,"endTime":3324.332,"body":"There's a, there's a, there's a, there's a lot to it, a lot of discussion"},{"startTime":3324.332,"endTime":3324.557,"body":"and a lot of, and it's very important that the process is as inclusive as"},{"startTime":3324.557,"endTime":3327.925,"body":"possible."},{"startTime":3328.225,"endTime":3332.417,"body":"And one of the things, so, um, you know, just to big up physics on"},{"startTime":3332.417,"endTime":3332.696,"body":"this, yes, we have to make these decisions in the climate physics community, and they"},{"startTime":3332.696,"endTime":3339.125,"body":"make differences of like a 10th of a degree."},{"startTime":3339.545,"endTime":3344.008,"body":"The economists make decisions and they make differences of like factors of two or three,"},{"startTime":3344.008,"endTime":3344.306,"body":"you know, so, so, or, or more so, so, you know, let's be clear where"},{"startTime":3344.306,"endTime":3349.365,"body":"the uncertainties are."},{"startTime":3349.505,"endTime":3352.827,"body":"And it, you know, it's not the economist's fault, it's just that, you know, that's"},{"startTime":3352.827,"endTime":3355.485,"body":"where, um, that, that, that's where a lot of the uncertainties lie."},{"startTime":3355.925,"endTime":3361.941,"body":"I think it is very important in doing our science to be clear what is"},{"startTime":3361.941,"endTime":3362.342,"body":"sort of dictated by the world out there and what we're bringing to the problem"},{"startTime":3362.342,"endTime":3370.365,"body":"in terms of our own preconceptions."},{"startTime":3370.785,"endTime":3376.71,"body":"So, you know, when, and that, that for, um, for in, in, for the physical"},{"startTime":3376.71,"endTime":3381.845,"body":"science part, the argument about whether krato should count as representative of pre-industrial."},{"startTime":3382.395,"endTime":3382.685,"body":"Okay."},{"startTime":3382.685,"endTime":3385.748,"body":"Fortunately, it didn't make that much difference, you know, and, you know, as I said,"},{"startTime":3385.748,"endTime":3386.565,"body":"I lost that argument."},{"startTime":3386.565,"endTime":3387.685,"body":"It didn't, it didn't really matter."},{"startTime":3388.145,"endTime":3392.732,"body":"Um, and, uh, but the argument about whether we should assign equal weights to a"},{"startTime":3392.732,"endTime":3393.038,"body":"dollar lost to a Congolese, to a dollar lost to a Canadian, that makes a"},{"startTime":3393.038,"endTime":3393.343,"body":"huge amount of difference to the outcome of how much you, how you weight different"},{"startTime":3393.343,"endTime":3393.649,"body":"levels of warming or, or a dollar loss to, you know, a, a school child"},{"startTime":3393.649,"endTime":3393.955,"body":"today, um, in, you know, when they're in their eighties compared to a dollar loss"},{"startTime":3393.955,"endTime":3414.445,"body":"to a pensioner today who's already in their eighties, for example."},{"startTime":3414.565,"endTime":3417.485,"body":"I mean, you know, so, so, um, these are, sorry."},{"startTime":3417.485,"endTime":3420.525,"body":"It's, it's a feature of economics that everything's in dollars."},{"startTime":3420.725,"endTime":3421.885,"body":"I don't, uh, sorry about that."},{"startTime":3422.225,"endTime":3426.04,"body":"Um, but, um, uh, and so, so, so I, I do think one of the"},{"startTime":3426.04,"endTime":3426.295,"body":"things we have to do is be very clear what's our preconceptions versus what's come"},{"startTime":3426.295,"endTime":3430.365,"body":"from outside."},{"startTime":3430.505,"endTime":3434.749,"body":"The other thing we have to really work on is, and something that the whole"},{"startTime":3434.749,"endTime":3435.032,"body":"climate science community is, is working on, is being more inclusive of different perspectives in"},{"startTime":3435.032,"endTime":3440.125,"body":"the research process itself."},{"startTime":3440.625,"endTime":3445.077,"body":"Um, because, you know, for a long time, climate science was very heavily dominated by"},{"startTime":3445.077,"endTime":3448.045,"body":"people who looked like me, to be honest with you."},{"startTime":3448.425,"endTime":3452.056,"body":"Um, and, and that's, you know, and that's a problem, uh, because it's not really"},{"startTime":3452.056,"endTime":3455.445,"body":"up to us to, you know, pontificate to the world how they should behave,"},{"startTime":3456.155,"endTime":3458.205,"body":"Just, uh, just on the costs."},{"startTime":3458.545,"endTime":3462.538,"body":"You, you described them in a sort of quadratic as though there is a smooth"},{"startTime":3462.538,"endTime":3462.805,"body":"increment."},{"startTime":3463.305,"endTime":3469.366,"body":"And I'm just wondering, taking Krater as a example on the other side, whether, whether"},{"startTime":3469.366,"endTime":3469.77,"body":"you see these costs as mainly incremental, or are there some big costs that come"},{"startTime":3469.77,"endTime":3477.045,"body":"at various tipping points?"},{"startTime":3477.265,"endTime":3480.405,"body":"Yes, that need to be factored in."},{"startTime":3480.905,"endTime":3484.97,"body":"We have a whole lecture on tipping points later this year, so come back for"},{"startTime":3484.97,"endTime":3486.325,"body":"our lecture on tipping points."},{"startTime":3486.865,"endTime":3489.125,"body":"If that's, if that's a, if that's a reasonable answer."},{"startTime":3489.245,"endTime":3494.816,"body":"I mean, it's, um, but, but yes, but for these, at the moment in our"},{"startTime":3494.816,"endTime":3499.645,"body":"models for these small levels of warming, things seem to happen relatively smoothly."},{"startTime":3501.225,"endTime":3503.725,"body":"Um, that doesn't mean that's true of the real world."},{"startTime":3504.025,"endTime":3508.18,"body":"Um, and indeed in the real world, things in, when it comes down to impacts,"},{"startTime":3508.18,"endTime":3508.457,"body":"particularly impacts on extreme weather, which we will be talking about in the next lecture"},{"startTime":3508.457,"endTime":3513.445,"body":"coming up in January."},{"startTime":3514.065,"endTime":3516.765,"body":"Um, things do seem to be happening rather by fits and starts."},{"startTime":3516.985,"endTime":3520.805,"body":"Um, and perhaps not, not as smoothly as we would've liked."},{"startTime":3521.425,"endTime":3525.695,"body":"Um, so, so yeah, no, this is, this is a, this is a, a big,"},{"startTime":3525.695,"endTime":3525.979,"body":"a big issue, but, but the difficulty you, we have is that if you can't"},{"startTime":3525.979,"endTime":3526.264,"body":"predict when a jump will occur, it's almost like it, it's smooths the uncertainty smooths"},{"startTime":3526.264,"endTime":3534.805,"body":"it out."},{"startTime":3535.425,"endTime":3540.456,"body":"If you, yeah, I mean, it's still there, but it's sort of, it's smoothed by"},{"startTime":3540.456,"endTime":3542.805,"body":"uncertainty, if you see what I mean."},{"startTime":3543.515,"endTime":3543.805,"body":"Yeah."},{"startTime":3544.465,"endTime":3547.947,"body":"In, in, in the way, in our thinking, if not in our, in, not in"},{"startTime":3547.947,"endTime":3549.805,"body":"reality and not in the experience of it."},{"startTime":3550.435,"endTime":3550.725,"body":"Okay."},{"startTime":3550.975,"endTime":3555.015,"body":"We'll get onto this in the tipping points lecture, if that sounded very mysterious to"},{"startTime":3555.015,"endTime":3555.285,"body":"you."},{"startTime":3555.435,"endTime":3556.325,"body":"Okay, thank you very much."},{"startTime":3556.465,"endTime":3560.405,"body":"And in the meantime, please join me in thanking our guest speaker tonight, professor."}]}