1 00:00:00,120 --> 00:00:03,120 Thanks very much. I'm delighted. Honoured. 2 00:00:03,150 --> 00:00:09,600 So you'll come to. To hear this lecture? I, I very much hope you enjoy and gets me out of it. 3 00:00:10,890 --> 00:00:19,170 And, ah, of course, I'm very grateful to the the ECI and the Smith School in particular, for hosting this event. 4 00:00:20,220 --> 00:00:23,610 And crucially, that means providing free drink afterwards. 5 00:00:23,610 --> 00:00:28,740 So I know why most people are here to guarantee a good turnout and so on. 6 00:00:29,520 --> 00:00:36,060 But but I, of course, particularly should start off by thanking the school geography, 7 00:00:36,120 --> 00:00:41,670 environment and the Department of Physics School of Environment for giving me the opportunity 8 00:00:42,320 --> 00:00:48,150 to to talk to you today as the driver entrusting me with one of their statutory chairs. 9 00:00:48,480 --> 00:00:56,309 I have to try not to break it, I suppose, and and the Department of Physics for having shepherded me this far and also continue 10 00:00:56,310 --> 00:01:01,710 allowing me to continue my involvement in the department as as we go forwards. 11 00:01:03,420 --> 00:01:08,580 I am joining in a sort of inaugural lecture like this. 12 00:01:09,060 --> 00:01:17,220 I gather it's customary to start off with a sort of bit of an autobiographical spin on on why I got to where I am. 13 00:01:17,520 --> 00:01:22,710 And also a lot of people here looking around the room know me anyway, so I think I'll spare you that embarrassment. 14 00:01:24,030 --> 00:01:35,879 But I will make one little comment on along those lines, because I'm joining a department where I've discovered unnervingly that. 15 00:01:35,880 --> 00:01:44,460 So the researcher is often the subject of investigation as well as the thing the researcher is investigating. 16 00:01:45,480 --> 00:01:50,760 And I also wanted rather unnerving talking to Sarah Watt more than 9 a.m. 17 00:01:50,760 --> 00:01:55,110 I might really talk to her. Is she just analysing who I am, so to speak, or what I'm doing? 18 00:01:55,710 --> 00:02:00,300 And so I'm going to struggle with this anyway. 19 00:02:00,930 --> 00:02:12,360 So the, the, the reason I thought I should therefore start off with a declaration which I thought would prompt a theme for this lecture, 20 00:02:13,350 --> 00:02:18,570 is that, as many of you know, mines the second career in our family. 21 00:02:19,620 --> 00:02:24,480 My wife Irene got her statutory chair a few years ago, and partly as a result, 22 00:02:24,510 --> 00:02:30,780 I have the privilege of meeting our kids at 3:00 every afternoon at the primary school gates. 23 00:02:31,470 --> 00:02:39,420 And it's very striking how working on climate change and big planetary environmental 24 00:02:39,420 --> 00:02:48,990 problems doesn't fit in with my role as a parent in a North Oxford primary school. 25 00:02:49,740 --> 00:02:54,420 And that's kind of what the title of the lecture is all about. 26 00:02:55,170 --> 00:02:58,290 When I it's a it's a classic North Oxford Primary School. 27 00:02:58,290 --> 00:03:04,649 People are concerned about the environment. People several parents are here have seen and they sort of asked me plenty what I do. 28 00:03:04,650 --> 00:03:08,590 And they're interested. Oh, yes. Climate change and and and they're concerned about that. 29 00:03:08,620 --> 00:03:12,779 Several have solar panels on their roofs and so on. And we talk about them. 30 00:03:12,780 --> 00:03:17,340 We move on and talk about other things. And then I go to conferences and people talk about, you know, 31 00:03:17,640 --> 00:03:27,780 is it a 10% or 2% probability of a third headline shut down affecting the climate of Europe in 50 to 100 years time? 32 00:03:28,170 --> 00:03:30,750 And it just doesn't connect up at all. 33 00:03:31,770 --> 00:03:42,480 And it's this disconnect between what we do as climate scientists and indeed what politicians do without climate science. 34 00:03:43,110 --> 00:03:51,490 So it's this some sort of triangle we have to try and reconnect that I'm thinking about in this inaugural lecture. 35 00:03:52,380 --> 00:03:57,630 We've got the sort of stuff we do as climate scientists making these projections of the 36 00:03:57,630 --> 00:04:05,640 world which look disturbingly predictable and wander off into the future at some alien date, 37 00:04:05,760 --> 00:04:12,330 a long way away. We have politicians making, you know, 38 00:04:12,450 --> 00:04:19,530 pronouncements about their commitment to avoid more than two degrees of warming and so forth at these big international conferences. 39 00:04:20,460 --> 00:04:27,060 And then we have reality. We have actual people at the school gates getting on with their lives. 40 00:04:27,690 --> 00:04:31,280 And there's very little connection between between these three. 41 00:04:31,500 --> 00:04:36,060 The lack of connection between climate science and climate policy has been very heavily discussed, 42 00:04:36,960 --> 00:04:42,150 and I've been engaged in some of those discussions and I'm enjoying continued discussions as we go forward. 43 00:04:42,960 --> 00:04:51,930 But it's this disconnect between what we do as scientists and the questions people are really interested in that I want to focus on in this lecture, 44 00:04:52,650 --> 00:05:00,510 because one of the things I one of the conclusions I guess I'll try and convince you of is that if as a scientific community, 45 00:05:00,660 --> 00:05:06,150 we've done a better job of focusing on the questions ordinary people really are interested in, 46 00:05:06,390 --> 00:05:16,770 we might not be in quite such a pickle as we're in as regards climate science and its role in them in policy. 47 00:05:18,240 --> 00:05:19,440 As you probably know, 48 00:05:19,440 --> 00:05:28,140 the rules of the lecture are that you're allowed to ask questions and it all has to proceed in complete silence until the privacy and myself file out. 49 00:05:28,980 --> 00:05:33,030 And so when when I heard these rules, I thought, this, this, this is never going to work. 50 00:05:33,030 --> 00:05:37,820 And it's going be very boring for everybody, which is why I'm also so. 51 00:05:37,910 --> 00:05:41,940 So that's why we sort of introduced this format and a panel discussion afterwards. 52 00:05:42,330 --> 00:05:46,470 And I'm, of course, very grateful to the panel for coming up. 53 00:05:47,010 --> 00:05:54,990 David, Bob, Sarah and Richard. And you'll be hearing from all of them after the lecture, and that'll be an opportunity for everybody. 54 00:05:55,260 --> 00:06:00,239 There'll be roving mikes and everybody can join in and discuss what we've been what we've been talking about. 55 00:06:00,240 --> 00:06:04,440 So to make notes of the things you wish to disagree with, because I hope there will be plenty. 56 00:06:06,090 --> 00:06:12,420 So this is the challenge we face and the situation we're in, 57 00:06:12,870 --> 00:06:18,450 sort of being realistic about climate and about the way the climate issues evolved over the past 20 years. 58 00:06:19,980 --> 00:06:21,660 What's been achieved? I said very little. 59 00:06:21,820 --> 00:06:27,780 What's been achieved in the sense of doing anything about climate change, in the context of the problem as a whole is very little. 60 00:06:27,960 --> 00:06:34,870 An enormous amount has been achieved over the past 20 years in terms of understanding the problem and to some extent how. 61 00:06:34,920 --> 00:06:39,780 I'll try and convince you in understanding how relatively simple it is, at least on the large scale. 62 00:06:40,110 --> 00:06:43,710 And then we can come on to how potentially complicated it might be on smaller scales. 63 00:06:44,280 --> 00:06:49,140 And then I'll talk about in the context of what has been achieved, in the context of what needs to be achieved. 64 00:06:50,040 --> 00:06:57,450 And that's the challenge we face of an eventual phaseout of anthropogenic greenhouse gas emissions. 65 00:06:57,990 --> 00:07:07,680 And the problem we have having facing that 50 to 100 year time scale challenge is facing where most people's priorities lie, 66 00:07:07,980 --> 00:07:13,110 which is essentially present day climate understanding, today's climate and current climate trends. 67 00:07:14,040 --> 00:07:21,869 And most people who I talk to at the school gates are not really that interested in forecasts of the 68 00:07:21,870 --> 00:07:28,740 climate in 2100 or estimates of the probability of events happening in their grandchildren's lifetimes, 69 00:07:29,370 --> 00:07:35,460 or even our ability to make marginally skilful, multi-decade climate predictions. 70 00:07:36,420 --> 00:07:42,420 So this is it's that it's that connection that we want to try and remake in this. 71 00:07:42,420 --> 00:07:46,889 And that's the sort of direction that I'm going in terms of making the link between 72 00:07:46,890 --> 00:07:51,930 the physics departments and the School of Geography as part of this research. 73 00:07:53,300 --> 00:07:57,800 Just in terms of giving you the context of where we're at, in terms of emissions. 74 00:07:57,950 --> 00:08:03,640 We've been doing some work with Corinne le Carré in the Tyndall Centre, UEA Tyndall, 75 00:08:04,010 --> 00:08:12,260 and she has a very nice way of framing the problem of understanding how emissions are evolving. 76 00:08:12,560 --> 00:08:22,400 Thinking from the top down in the big picture, how emissions per head emissions per person in different parts of the world are evolving. 77 00:08:22,820 --> 00:08:26,660 I find this very intriguing figure. So that's the UK there. 78 00:08:26,660 --> 00:08:31,130 So the black line is real data, that's emissions tonnes of carbon per person. 79 00:08:31,310 --> 00:08:36,110 Okay. So you can see in the UK and it starts in 1750 here and goes up to 2050. 80 00:08:36,500 --> 00:08:43,940 So the UK, we sort of peaked a few decades ago and it's now perhaps coming down in emissions per person. 81 00:08:44,630 --> 00:08:52,280 But you know, perhaps that's just noise. So we have to sort of consider the possibility that this might just be a noise about a stabilisation. 82 00:08:52,790 --> 00:08:56,840 The USA has shot up faster, may be coming down faster. 83 00:08:57,080 --> 00:09:00,170 Or is it just noise and it's about to stabilise. Okay. 84 00:09:00,560 --> 00:09:09,440 So so this is the sort of range of uncertainty in where emissions might go next given the amount of information we've got so far. 85 00:09:09,440 --> 00:09:13,309 But most of these mature countries, we're seeing at least some sort of inflation, 86 00:09:13,310 --> 00:09:17,420 which gives you a bit of a constraint on what might be happening next. 87 00:09:18,950 --> 00:09:25,050 Of course, somewhere like China, you're very much in a very different situation. 88 00:09:25,070 --> 00:09:32,840 You know, we've got emissions per head taking off. You can basically fit any function you like to this sort of curve. 89 00:09:33,200 --> 00:09:39,950 And you could go. So, so then of course, you've got to use more information to try and put some bounds on what might happen in the future. 90 00:09:40,280 --> 00:09:44,929 And so Koreans considering the possibility that China might tap out. 91 00:09:44,930 --> 00:09:55,830 It's an American style cap of six odd tonnes per person, per head or cap out of the European style maximum of two and a half. 92 00:09:56,210 --> 00:10:02,060 And these are sort of the point is here is to sort of use the sort of the overall shape 93 00:10:02,060 --> 00:10:07,220 of the way emissions are evolving as a way of giving bounds on emissions in the future. 94 00:10:07,370 --> 00:10:12,649 The normal way of doing this kind of thing, by the way, is very different, is to set up something called an integrated assessment model, 95 00:10:12,650 --> 00:10:19,430 which has a model of the transport sector, a model of the power sector and so forth, and and sort of try and model everything into the future. 96 00:10:19,640 --> 00:10:24,400 This is very much a much more sort of top down, data driven approach, which I like. 97 00:10:24,410 --> 00:10:28,760 I mean, certainly it's certainly much closer to the sort of things we've been trying to do with climate. 98 00:10:30,050 --> 00:10:35,840 But of course, because there's less information going in, you end up with a lot of uncertainty in what comes out. 99 00:10:36,110 --> 00:10:44,000 However, because of the properties of CO2, which will come back to a lot of these uncertainties, 100 00:10:44,620 --> 00:10:48,980 in effect integrate out because CO2 accumulates in the climate system. 101 00:10:49,520 --> 00:10:59,719 And what we find is the what matters really for the climate system is the total integrated amount of CO2 we dump in the atmosphere over all time, 102 00:10:59,720 --> 00:11:03,920 not the amount we dump in any given year. We'll be coming back to that theme fairly frequently. 103 00:11:04,520 --> 00:11:16,580 And so the process that even given these very large range of possible behaviour in emissions per head of population, 104 00:11:17,000 --> 00:11:20,090 when you multiply that by what we actually know, 105 00:11:20,090 --> 00:11:27,499 rather with considerable confidence, which is actually how the population is going to evolve between now and 2050, 106 00:11:27,500 --> 00:11:31,760 because those those trends, you know, there's a lot of inertia in population. 107 00:11:31,760 --> 00:11:35,600 You can actually make projections that far ahead with a reasonable amount of confidence. 108 00:11:36,260 --> 00:11:46,790 You end up with a relatively small range of uncertainty in accumulated carbon emissions from fossil sources out in 2050. 109 00:11:47,090 --> 00:11:57,150 And it's in the ballpark of the upper end of the ranges of onset, of the projections of the scenarios that are out there at the moment. 110 00:11:57,170 --> 00:12:10,070 So the this sort of approach points towards a future at least over the next 40 to 50 years where we're following the high end scenarios of emissions. 111 00:12:10,640 --> 00:12:16,010 And that is certainly consistent with the emissions data that's been released relatively recently, 112 00:12:16,010 --> 00:12:19,309 although of course, you shouldn't read too much into just one or two years. 113 00:12:19,310 --> 00:12:27,440 But certainly the bounce back from the recession in emissions was such that most people are saying that does appear to be the sort of path we're on. 114 00:12:27,710 --> 00:12:38,060 So on the sort of area of what's happening to global emissions, there's absolutely no sign of a slowdown in fossil carbon emissions at the moment. 115 00:12:38,570 --> 00:12:45,830 If anything, we're seeing a modest acceleration in the rate of CO2 emission into the atmosphere. 116 00:12:47,510 --> 00:12:52,340 What what a lot of people are reporting as having slowed down is the climate. 117 00:12:52,410 --> 00:12:57,780 Response. You'll read a lot in particularly in certain newspapers, 118 00:12:57,780 --> 00:13:03,540 but also on the Internet and blog sites and so forth, about how global warming stopped in 1998. 119 00:13:04,500 --> 00:13:16,830 If it if if it were true that more than we more than we thought of the warming that occurred prior to the year 2000 was a natural fluctuation. 120 00:13:17,490 --> 00:13:27,410 And if the current shorts relatively short period of relatively stable temperatures were to continue, that would, of course, be reassuring. 121 00:13:27,420 --> 00:13:30,660 It wouldn't mean that everything we've done so far is wrong, 122 00:13:30,870 --> 00:13:39,480 but it would mean we'd start to be able to rule out some of the upper end of the possible responses of the climate system to these rising emissions. 123 00:13:40,080 --> 00:13:50,520 At the moment, however, there isn't that much reassurance in what we've seen so far because we can, in fact explain what's happened since 1998. 124 00:13:50,860 --> 00:14:01,919 That's 1998 here, the spike in temperatures. The grey here is the data and the various colours are different authors attempts at explaining what's 125 00:14:01,920 --> 00:14:09,810 happened in the data due to different factors affecting global temperatures over the past 50 to 100 years. 126 00:14:10,110 --> 00:14:20,220 This is a figure that trembles here in maths and physics has been putting together as part of the preparation for the next IPCC assessment. 127 00:14:21,120 --> 00:14:29,639 And what it shows is, is that it's possible to explain, not necessarily this is the correct explanation, 128 00:14:29,640 --> 00:14:35,520 but this is a possible explanation of what's happened to global temperatures over the past 50 years. 129 00:14:35,850 --> 00:14:45,629 And these explanations typically involve, from 1998 onwards, quite a bit of cooling due to the non-recurrence, 130 00:14:45,630 --> 00:14:50,260 if you like, of an extreme El Nino event such as the one we had in 1998. 131 00:14:50,280 --> 00:14:57,060 So we've we haven't seen another El Nino like the one in 1998 or indeed the one in 1982. 132 00:14:57,750 --> 00:15:03,510 Those were those are very strong El Nino events. They give a big upward spike into the global temperature series. 133 00:15:03,720 --> 00:15:08,250 We haven't seen another one. So that record is for that reason yet to be broken. 134 00:15:08,970 --> 00:15:18,150 We've also seen the El Nino occurred at a time when there wasn't the cooling due to the early nineties 135 00:15:18,150 --> 00:15:27,810 volcano had largely dissipated and it also occurred at a time when solar activity was relatively high. 136 00:15:27,990 --> 00:15:34,990 And we've seen a little downturn in temperature due to solar activity over the past ten years. 137 00:15:35,010 --> 00:15:41,820 So we're now at a relatively weak part of the solar cycle, whereas ten years ago it was a little bit stronger. 138 00:15:42,030 --> 00:15:47,130 You're pretty finding it irritating if you're at the bank. Why have I got one of these scales so big and these lines so small? 139 00:15:47,250 --> 00:15:50,820 Well, that's kind of the point here, is these are not big wiggles. 140 00:15:51,390 --> 00:15:55,709 And they're not particularly they're not in terms of at the school gates. 141 00:15:55,710 --> 00:15:57,510 These are not particularly important wiggles. 142 00:15:57,720 --> 00:16:05,250 They matter for scientists because, of course, if we couldn't explain what was happening since that time, 143 00:16:05,250 --> 00:16:11,910 if there was a genuine evidence of a problem with our understanding of the way the climate system was responding to those emissions, 144 00:16:12,240 --> 00:16:19,530 then, you know, we'd perhaps be backing off the whole projections we're making about further warming in the future, but there isn't such a problem. 145 00:16:19,710 --> 00:16:25,800 We can see that. We can explain what's going on as a combination of these natural factors affecting 146 00:16:25,800 --> 00:16:31,050 climate and the anthropogenic influence estimated from these different studies. 147 00:16:31,080 --> 00:16:39,450 And you can see all of them agree we're seeing a substantial anthropogenic warming over the past over the past few decades. 148 00:16:40,430 --> 00:16:44,310 And one one question is which which comes out of this, of course, 149 00:16:44,760 --> 00:16:50,100 is there is an element this is sort of explaining after the event things have happened. 150 00:16:50,100 --> 00:16:52,500 So we go out and look for reasons why they've happened. 151 00:16:52,740 --> 00:17:01,590 Scientists are disturbingly good at this, as Sara will point out, and we were very often brilliant with hindsight. 152 00:17:02,370 --> 00:17:06,899 And we do need to be careful about the possibility or indeed the sort of formal statistical 153 00:17:06,900 --> 00:17:11,240 danger of overfitting when we're trying to explain every wiggle in the Time series like that. 154 00:17:11,250 --> 00:17:15,540 And I wouldn't suggest that we should expect to be able to explain all the wiggles 155 00:17:15,540 --> 00:17:19,830 in global temperature and the sort of detail that those studies have demonstrated. 156 00:17:20,160 --> 00:17:23,940 So just to convince you, though, that it isn't all just being wise after the event, 157 00:17:24,240 --> 00:17:34,830 I thought I'd show you one genuine prediction of global mean temperature of global climate made in a paper submitted in the last millennium. 158 00:17:36,000 --> 00:17:40,440 And this is a prediction of global temperature based on data. 159 00:17:40,800 --> 00:17:45,990 Banks in the data available was only available up until 1996. 160 00:17:45,990 --> 00:17:52,049 Although we submitted the paper in 1999, we weren't quite as good in those days, that sort of gathering data together. 161 00:17:52,050 --> 00:18:00,050 And so. And so we are now in a position more than 14 years later to look at how good that 162 00:18:00,050 --> 00:18:05,810 forecast was of the decade following the point at which the forecast was made. 163 00:18:06,320 --> 00:18:13,310 I and the reason I like the number 14 is there's a precedent for 14 year climate forecasts. 164 00:18:14,330 --> 00:18:18,940 And you'll notice how seriously in those days people took the climate scientist. 165 00:18:20,190 --> 00:18:24,170 And if only the same were true today. 166 00:18:24,740 --> 00:18:29,320 So the crucial point here, this was the article in question. 167 00:18:29,330 --> 00:18:34,310 And if I just zoom in, you'll notice they did receive it in the last millennium. 168 00:18:35,720 --> 00:18:40,700 And I'd just like to publicly apologise to Irene for submitting a paper, 169 00:18:40,700 --> 00:18:46,400 and thank you for giving me the opportunity of doing so and rather just spoiling our Christmas that year, as I recall. 170 00:18:46,970 --> 00:18:53,629 But I was kind of obsessed with getting this thing in. And it is satisfying that it went in just with one view. 171 00:18:53,630 --> 00:19:00,590 This is we can we can stand up and say hand on heart. The forecast of the next decade was completely out of sample. 172 00:19:00,770 --> 00:19:04,050 Okay. Yes, the paper was published in 2000. We didn't fiddle with the figures. 173 00:19:04,070 --> 00:19:08,090 Okay. So everything. And so this is what happened. That was 14 years later. 174 00:19:08,450 --> 00:19:14,350 That's the validation, I think. Now, of course, there's an element of luck in this. 175 00:19:14,360 --> 00:19:18,440 It could have. It could have been basically, we were saying could have been anywhere inside that great curve. 176 00:19:18,710 --> 00:19:27,020 But the point is that the actual average temperature over the past decade was exactly 177 00:19:27,320 --> 00:19:31,910 what we expected it to be based on the information we had back in the 1990s. 178 00:19:32,240 --> 00:19:36,680 It's not that we can explain it after the event. It was it was explained before the event. 179 00:19:37,100 --> 00:19:40,640 And this is one demonstration, of course, which I'm fond of because I played a role in it. 180 00:19:40,850 --> 00:19:42,409 But there's other papers out there. 181 00:19:42,410 --> 00:19:49,910 You can go back to what the IPCC was saying in the 1990s and say, you know, what would they have forecast for where we would be today? 182 00:19:50,120 --> 00:19:54,290 And it is remarkable how close we are to where we were predicted to be. 183 00:19:55,700 --> 00:20:00,560 So that's sort of telling you that there's certainly no evidence that global warming is stopped. 184 00:20:01,340 --> 00:20:04,760 We do understand why the 1998 record is yet to be broken. 185 00:20:05,480 --> 00:20:17,120 And we shall. And some people, in fact, argue that it, in fact, has been broken, or at least is a statistical tie and emissions continue, if anything. 186 00:20:17,630 --> 00:20:24,470 So they the the trends are pointing towards an acceleration and the climate is responding much as expected. 187 00:20:24,650 --> 00:20:30,710 One of the questions I get often, often get asked is, is it true that it's sort of turning out worse than we thought? 188 00:20:31,040 --> 00:20:35,750 My impression is the evidence is coming in, some of it worse than we thought, some of it. 189 00:20:36,230 --> 00:20:42,740 But it's sort of you know, it's not obvious that in many ways what's remarkable is the evidence is coming in so 190 00:20:42,740 --> 00:20:49,130 close to what we expected that the system is evolving and in some ways surprising, 191 00:20:49,160 --> 00:20:53,240 surprisingly simply compared to us at a global level. 192 00:20:54,050 --> 00:21:03,709 Tim. Tim is frowning there. There's any suggestion this is a simple system at a global level on in response to changing greenhouse gases. 193 00:21:03,710 --> 00:21:08,300 And we're not seeing any imminent reductions in fossil CO2 emissions. 194 00:21:08,630 --> 00:21:10,850 So in that sort of rather depressing context, 195 00:21:11,600 --> 00:21:21,229 could we make more progress perhaps on alternatives to CO2 and other drivers of carbon dioxide of climate than than CO2, 196 00:21:21,230 --> 00:21:27,920 which is something which has been proposed and is will, I'm sure, receive a lot of coverage in the next couple of years. 197 00:21:28,400 --> 00:21:31,730 There's a lot of because we're basically not making any progress on CO2. 198 00:21:32,300 --> 00:21:39,170 This has led to a lot of enthusiasm for trying to do something about climate change by reducing emissions of black carbon. 199 00:21:39,170 --> 00:21:43,220 So soot from a lot of it from burning biomass in developing countries. 200 00:21:43,670 --> 00:21:54,469 Tropospheric ozone generated by photochemical pollutants and and and many other many other kinds of blue pollution and methane, 201 00:21:54,470 --> 00:22:03,740 of course, from agriculture and natural gas reductions. I promise to members of the audience at least one reference to trans fats in this election. 202 00:22:03,740 --> 00:22:06,770 So that is one gratuitous reference to the farting cow. 203 00:22:07,430 --> 00:22:10,190 These are we want to emphasise bad things. 204 00:22:10,880 --> 00:22:18,830 We agree with the unit report's assessment completely that it would be very good for the world and good for women 205 00:22:18,830 --> 00:22:23,810 in developing countries in particular to do something about the things that cause emissions of black carbon. 206 00:22:24,470 --> 00:22:33,320 These things poison a lot of people in developing countries, a lot of very good reasons for cutting them, unfortunately for political reasons. 207 00:22:34,070 --> 00:22:41,299 A lot of people want to say that meeting the target of avoiding more than two degrees of warming is one of these reasons, 208 00:22:41,300 --> 00:22:45,030 because they've made this commitment. They made a commitment to avoid more than two degrees of warming. 209 00:22:45,050 --> 00:22:48,230 They want to be seen to be doing something about it. 210 00:22:48,230 --> 00:22:51,770 And this appears to be something easy they can do. However. 211 00:22:52,550 --> 00:22:56,000 And the you know, the early drafts of the unit report. 212 00:22:56,000 --> 00:22:59,810 I don't know what they're going to say in the version of the report which is released tomorrow. 213 00:23:00,770 --> 00:23:03,830 In fact, I didn't even know it was going to be released tomorrow until which you told me earlier on today. 214 00:23:04,430 --> 00:23:08,300 But in the executive summary of this report, which they released earlier this year, 215 00:23:08,540 --> 00:23:15,740 it contained the statement reducing short lived climate forcings will help keep global temperature rise below two degrees. 216 00:23:16,340 --> 00:23:18,829 And that's a politically very convenient thing to be able to say, 217 00:23:18,830 --> 00:23:23,180 because we're trying to do that and we want to reduce these short lived climate forcings. 218 00:23:23,390 --> 00:23:27,530 So you put the two together and it all looks very good. The only problem is it's not true. 219 00:23:29,120 --> 00:23:33,420 Okay. The reason it's not true is that these things are short lived. 220 00:23:33,440 --> 00:23:36,320 They don't live. They don't survive in the atmosphere for very long. 221 00:23:36,530 --> 00:23:44,540 Which means that emissions we make of these short lived forcing agents today make very little difference to the risk of going over two degrees. 222 00:23:44,750 --> 00:23:52,610 It's a relatively obvious point, but one which we've been in prompted by this unit document to look into. 223 00:23:53,060 --> 00:24:01,730 And Neil Bauman, one of one of my graduate students, has been working with Steve Smith of the UK Climate Change Committee on this problem. 224 00:24:02,480 --> 00:24:16,190 And what this plot, which Neil's produced, shows how in one particular little model the emissions in different decades impact on peak warming. 225 00:24:16,550 --> 00:24:26,150 Okay. So what you're seeing here is the emissions we make in the 2000 in the in the 20 tens. 226 00:24:26,150 --> 00:24:29,580 Would that column be. No, that would be the 20 tens again. 227 00:24:29,840 --> 00:24:36,709 So in this decade, the the the emissions we pump into the atmosphere under this scenario, 228 00:24:36,710 --> 00:24:41,750 which is a scenario in which temperatures are expected to peak around two degrees, 229 00:24:42,470 --> 00:24:49,670 the emissions we make in this decade contributes about 2/10 of a degree to that two degrees. 230 00:24:50,210 --> 00:24:50,690 Okay. 231 00:24:51,350 --> 00:24:59,600 And so if somehow magically we followed this scenario, but we just didn't emit anything this decade, okay, then the peak would be 0.2 degrees lower. 232 00:25:00,350 --> 00:25:03,140 Yeah. These sort of with more or less what we're talking about. 233 00:25:03,320 --> 00:25:09,290 So so what we're saying here, this gives you an idea of which gases are most important when for peak temperatures. 234 00:25:09,800 --> 00:25:18,260 And notice, plain carbon, tropospheric ozone and methane are these quite small bars up at the top here, entirely dominated by CO2. 235 00:25:18,730 --> 00:25:24,450 I think they become important out in the future as you approach the peak. 236 00:25:24,620 --> 00:25:27,920 And at a time when you virtually eliminate your CO2 emissions anyway. 237 00:25:28,730 --> 00:25:34,219 But the bottom line is cuts in these other gases make very little difference to your risk 238 00:25:34,220 --> 00:25:38,510 of dangerous climate change in the future unless you've already got CO2 under control. 239 00:25:39,020 --> 00:25:42,740 And I hope I convinced you with Corinne's work, we haven't got CO2 under control. 240 00:25:42,770 --> 00:25:48,650 We shouldn't pretend that we have. So it's a convenient fiction, but sadly not true. 241 00:25:49,580 --> 00:25:56,670 The reason carbon dioxide is so important, of course, is that it's the one which builds up in the system. 242 00:25:56,690 --> 00:25:59,870 It's like a heavy metal toxin, so to speak. 243 00:26:00,470 --> 00:26:10,130 The dose of CO2 accumulates in the climate system, unlike the others, where if you cut emissions of methane within 10 to 20 years, 244 00:26:10,310 --> 00:26:15,950 the methane you've released into the atmosphere has oxidised into CO2 and 245 00:26:15,950 --> 00:26:20,510 therefore has much less impact on the planet than it would do as methane alone. 246 00:26:22,040 --> 00:26:27,409 The sort of demonstration of this point about the fact that it's the total amount of 247 00:26:27,410 --> 00:26:32,960 CO2 you dump in the atmosphere that matters is just illustrated by this figure here, 248 00:26:33,290 --> 00:26:42,950 which shows three different scenarios for future CO2 emissions on the left and the temperature response on the right. 249 00:26:43,580 --> 00:26:50,650 And so you've got a blue scenario which has emissions rising rapidly and then peaking suddenly in the early 2020s. 250 00:26:50,660 --> 00:26:54,680 Nobody is pretending these scenarios are plausible. They're just you know, we're physicists here. 251 00:26:54,680 --> 00:27:03,320 We're just sort of trying out to see what happens and then plummets at 8% per year and end up at a very low level by 2100. 252 00:27:03,590 --> 00:27:09,620 Again, alternate scenario here, the green one where they start falling soon and go down is only 3% per year. 253 00:27:10,010 --> 00:27:13,520 But crucially, the area, this green area is the same as that one. 254 00:27:13,820 --> 00:27:19,580 That blue area is the same as that one. So all of these curves have the same integral does the same area under the curve. 255 00:27:20,070 --> 00:27:23,360 Okay. So the same total amount of carbons released into the atmosphere. 256 00:27:23,660 --> 00:27:29,540 And by the time you get on to the 22nd century, the climate response is identical. 257 00:27:30,510 --> 00:27:35,840 Okay. And certainly, considering the uncertainty in the climate response, 258 00:27:36,050 --> 00:27:43,000 there's no there's no perceivable there's no perceptible difference between emitting carbon early and emitting carbon later. 259 00:27:44,180 --> 00:27:48,350 And there's more. It's the total amount of carbon. It's the carbon. 260 00:27:48,350 --> 00:27:51,920 It's the total carbon. Sorry, missing word. That's the total carbon that matters. 261 00:27:52,640 --> 00:28:02,090 And the other important point to make is there's plenty more where that came from in the sense that if we put past emissions here I'm sorry, 262 00:28:02,090 --> 00:28:08,720 this is slipped slightly, that should come to about half a trillion tonnes if we include conventional oil and gas reserves. 263 00:28:09,110 --> 00:28:13,700 That takes us up to a trillion tonnes. Oil, gas and coal. 264 00:28:13,850 --> 00:28:20,930 And so you can read off from this figure basically what temperature you would expect to peak at from the total amount of carbon you put in. 265 00:28:21,470 --> 00:28:28,550 So you release a trillion tons, you'd expect to peak around two degrees, which is what governments are aiming to try and keep the total figure to. 266 00:28:28,790 --> 00:28:35,719 If you burn all conventional oil, gas and coal, you've got plenty of carbon down that to take you up towards the four degree mark. 267 00:28:35,720 --> 00:28:40,990 And if you include all the shale gas reserves and so forth that people are now creatively uncovering, 268 00:28:41,210 --> 00:28:47,510 there's plenty of carbon there to take us into well territory we wouldn't want to explore with the simple climate model, 269 00:28:47,510 --> 00:28:54,830 at least possibly not with the real world either. So that's that's the situation we're in. 270 00:28:55,580 --> 00:29:00,649 And so the sort of brutal reality we're facing is that, yes, 271 00:29:00,650 --> 00:29:05,840 emissions over the next few decades will determine the risk of dangerous climate change because it's all building up in the system, 272 00:29:05,840 --> 00:29:13,790 it's emission and it's CO2 emissions that are doing that. But frustratingly, for politicians who really want a statement from the scientists saying, 273 00:29:14,780 --> 00:29:21,200 tell us what to do now, its emissions next year don't determine the risk of dangerous climate change. 274 00:29:21,860 --> 00:29:25,640 And so this is again, this is the tension we face. 275 00:29:25,880 --> 00:29:31,190 Is that the kind of statement politicians want scientists to be able to make, which is, you know, 276 00:29:31,190 --> 00:29:36,230 you have to peak by this state, simply can't be made because it's not the way the system works. 277 00:29:36,860 --> 00:29:37,820 You know, you could take. 278 00:29:40,520 --> 00:29:49,370 Either of any of those three trajectories and end up with the same climate outcome, probably a very different economic outcome, but some. 279 00:29:50,750 --> 00:29:54,620 So it's it's simply not true to stand up and say. 280 00:29:55,160 --> 00:30:01,850 From the point of view of as a as an ecological imperative, emissions have to peak by a certain date. 281 00:30:03,940 --> 00:30:14,740 Um, how can how can we, as climate scientists in this situation, how can we help us towards a sort of a lower regrets future? 282 00:30:15,760 --> 00:30:26,260 And this brings me back to the point about these very abstract projections of climate over the next century, 283 00:30:26,500 --> 00:30:31,720 following these idealised curves of emissions and temperature responses and so forth. 284 00:30:33,280 --> 00:30:38,950 There are an awful long way away from anything any normal person cares about, if you like. 285 00:30:39,760 --> 00:30:48,040 And one one question we need to ask ourselves is perhaps climate science could help more if we were to focus more on what people really care about, 286 00:30:48,040 --> 00:30:58,840 what what most people get most exercised about. When they're talking to me about climate, then the long term projections for 2100 and beyond. 287 00:30:59,950 --> 00:31:08,650 And those things are are not what's going to happen in 100 years time, but they're overwhelmingly what is happening now and why. 288 00:31:09,100 --> 00:31:22,570 So here's one example. The 2010 heat wave in Russia estimated to have caused around 50,000 deaths and around 15 billion loss to the Russian economy. 289 00:31:23,140 --> 00:31:28,180 The event in question was this massive heat wave where temperatures were up to 12 290 00:31:28,180 --> 00:31:35,050 degrees above normal over an extended period of weeks in western central Russia. 291 00:31:36,810 --> 00:31:43,200 And Moscow is clouded in data for weeks on end in this grey haze. 292 00:31:45,210 --> 00:31:49,920 Another event which goes very much in the public mind, the 2010 Pakistan floods. 293 00:31:50,970 --> 00:31:53,610 A really interesting question. Was it part of the same event? 294 00:31:53,640 --> 00:31:58,350 We don't really know that the answer to that question yet, but it's an interesting one to consider. 295 00:31:58,560 --> 00:32:07,980 This one caused fewer deaths, although and happening in the poorer country, probably fewer billions in terms of economic losses. 296 00:32:07,980 --> 00:32:13,920 But as a fraction of the wealth of that country was equally serious and of course, was followed up with further floods in 2011. 297 00:32:14,730 --> 00:32:23,700 And to get really serious, the 2003 floods of the I mean, the road, which may in fact, have had an impact on house prices, this. 298 00:32:24,420 --> 00:32:26,070 All of these are weather events. 299 00:32:26,280 --> 00:32:38,490 And to address this, the problem people the concerns people have about whether we have to understand how climate and weather are linked. 300 00:32:39,240 --> 00:32:47,620 And so the crucial. Little rhyme to take away with you to remember how this link works. 301 00:32:48,850 --> 00:32:54,639 Climate is what we expect. That's in the physicist or the statisticians sense of expectation. 302 00:32:54,640 --> 00:32:59,800 So it's the the average you would get from many, many realisations of the system you're studying. 303 00:33:00,310 --> 00:33:03,370 Weather is what we get and this particular realisation that we live in. 304 00:33:04,750 --> 00:33:12,489 And then of course when we're studying how external factors affect climate and whether it's climate that we affect and weather is what gets us, 305 00:33:12,490 --> 00:33:15,610 it's weather that actually does damage and affects people. 306 00:33:16,510 --> 00:33:19,360 And in making the link between climate and weather, 307 00:33:19,360 --> 00:33:24,730 we're perennially we're perpetually faced with the challenge illustrated beautifully by this cartoon, 308 00:33:25,510 --> 00:33:28,780 which I'll just read to me, because you can't visit the banks and the guy on the left saying he's very hot today, 309 00:33:29,020 --> 00:33:33,070 and the guy on the right says, yes, global warming. And the chances are, but it'll be cold next week. 310 00:33:33,220 --> 00:33:38,350 That's due to the unpredictable weather patterns caused by global warming. And then he says, if it's hot, it's global warming. 311 00:33:38,350 --> 00:33:42,730 If it's cold, it's proven global warming, too. And he says, yes, modern climatology is an easy science. 312 00:33:43,690 --> 00:33:48,399 So this is the challenge we face is that people definitely have a feeling that absolutely 313 00:33:48,400 --> 00:33:52,870 every weather event that happens around the world gets blamed on human influence, 314 00:33:52,870 --> 00:33:58,210 on climate, well, gets blamed on climate change. And of course, that's not justified. 315 00:33:58,780 --> 00:34:03,759 That's and the science that we're really interested in, 316 00:34:03,760 --> 00:34:09,159 in building on and through this link between the School of Geography and the Department of Physics 317 00:34:09,160 --> 00:34:17,080 here is actually making that link objective and robust so that we can say in quantitative, 318 00:34:17,080 --> 00:34:20,200 quantitatively, how climate change is affecting people around the world. 319 00:34:21,220 --> 00:34:29,260 I'll just take you through quickly, through the example of the Russian heat wave of the kind of analysis we do, 320 00:34:29,770 --> 00:34:36,160 because it illustrates the sort of tools we use to address this kind of question whether when a weather event happens, 321 00:34:36,520 --> 00:34:44,830 how can we say what the role of external drivers was in making that event either larger or more or less probable? 322 00:34:46,300 --> 00:34:49,420 This is what happened in 2010. 323 00:34:49,720 --> 00:35:00,370 We had what's called a blocking anti cyclone. You can see the flow around this high pressure system over western Russia and that's that 324 00:35:00,370 --> 00:35:04,450 the arrows show the flow of wind around that and this high pressure in the centre there. 325 00:35:04,870 --> 00:35:15,370 And the temperate surface temperatures rose to on average over the month of July, an average of six degrees above normal for that time of year. 326 00:35:16,330 --> 00:35:24,490 That was the characteristics of the heat wave we were looking at. There've been a couple of papers published already this year on the 2010 heat wave, 327 00:35:24,730 --> 00:35:28,690 interestingly reaching apparently diametrically opposite conclusions. 328 00:35:29,200 --> 00:35:36,700 So there's a paper by a group of American authors which report concluded that the heat wave was mainly due to natural, 329 00:35:36,700 --> 00:35:38,560 internal atmospheric variability. 330 00:35:38,950 --> 00:35:47,439 And another paper by a couple of German authors, which appeared more recently and said with an approximate 80% probability, 331 00:35:47,440 --> 00:35:50,950 the heat wave would not have occurred without climate warming. 332 00:35:51,670 --> 00:35:59,710 These are both very heavily reported papers. What was interesting was there was almost no overlap in who reported which paper, as you might imagine, 333 00:36:00,610 --> 00:36:06,400 but some that sort of as long as you have those kind of completely contradictory signing statements appearing, 334 00:36:06,760 --> 00:36:11,860 you're left with a challenge as to what the winner where is the scientific community at on this? 335 00:36:12,430 --> 00:36:16,479 We've been working on this. Friedrich, also in my group, 336 00:36:16,480 --> 00:36:22,420 has been working in particular on this problem to try and to try and disentangle what these authors had really 337 00:36:22,420 --> 00:36:28,360 found and see whether or not their conclusions were quite as contradictory as they first appear or indeed, 338 00:36:28,360 --> 00:36:34,059 as the authors appear to have thought. This is what happened July. 339 00:36:34,060 --> 00:36:41,260 Temperatures in western Russia and these are the observations they're bouncing around. 340 00:36:41,470 --> 00:36:50,680 And this red curve here is following a suggestion of John Von Oldenburg and I came to in the Netherlands. 341 00:36:51,430 --> 00:36:58,809 It's an empirical way of seeing how much you can explain the in a statistical sense, 342 00:36:58,810 --> 00:37:05,170 explain what's happened to central Russia temperatures in terms of what's happened to large scale temperatures around the world. 343 00:37:05,740 --> 00:37:09,640 And you can see that this sort of explained estimates, 344 00:37:09,940 --> 00:37:18,700 explained components of the central Russian temperature involves a small warming about two degree or so. 345 00:37:19,000 --> 00:37:23,160 But the anomaly that happened in 2010 was way bigger than that. 346 00:37:23,380 --> 00:37:23,780 I guys, 347 00:37:23,800 --> 00:37:33,640 we had this big excursion on the against the background of what you might on the basis of this empirical analysis think was a small warming trend. 348 00:37:33,940 --> 00:37:42,580 If you just take this data alone, the Russian data alone, and then you just take the full century and fit a straight line to it, you. 349 00:37:42,610 --> 00:37:44,500 Don't see a warming trend so. 350 00:37:44,680 --> 00:37:54,820 So you it does the signal I should stress if all you do is look at the data the signal is relatively weak and and unconvincing. 351 00:37:56,020 --> 00:38:00,520 What we've been and that's not particularly surprising if you're looking at a hundred 352 00:38:00,520 --> 00:38:06,220 years of data and in an event which might only happen once every hundred years. 353 00:38:06,310 --> 00:38:10,090 You're not going to see very many of them in order to be able to work out what's going on. 354 00:38:10,480 --> 00:38:20,139 So what we've been doing as saw over the past year is as part of the sort of sequence of experiments we've been doing under the Climate Prediction 355 00:38:20,140 --> 00:38:35,020 Dot Nets initiative is simulating the year 2010 and indeed all of the years since 1960 with our weather models just to see simulating many, 356 00:38:35,020 --> 00:38:41,380 many times to see how in the models, the frequency of extreme events changes over time. 357 00:38:41,680 --> 00:38:42,069 Okay. 358 00:38:42,070 --> 00:38:48,309 So it's in a sense doing a little bit better than the real world because if we've got a model, we can actually run it many times as the real world. 359 00:38:48,310 --> 00:38:53,890 We only got to run it once. So you can't. It's hard to tell if the statistics of extreme events are changing. 360 00:38:54,910 --> 00:39:03,280 We're doing this using these. If you're trying to study changing statistics of rare events, you need to simulate the system so many times. 361 00:39:03,280 --> 00:39:08,980 We certainly can't afford to run it on our own computers. And so with the support of Environment Guardian, 362 00:39:09,490 --> 00:39:15,430 we're doing the only way we can do this experiment is actually by recruiting our members of the public to do these runs for us. 363 00:39:16,060 --> 00:39:18,100 And we're obviously grateful to Guardian of supporting this. 364 00:39:18,130 --> 00:39:26,260 I'd have to say Damian Carrington is here this evening and has been instrumental in helping get this experiment off the ground. 365 00:39:28,420 --> 00:39:29,530 I should, of course, 366 00:39:29,530 --> 00:39:37,540 stress that further back climate action on it also had a lot of support from the BBC when we were doing longer term climate prediction experiments. 367 00:39:38,590 --> 00:39:42,940 These this is all laboratory. These are the people around the world who are doing these runs for us and 368 00:39:42,940 --> 00:39:47,649 continue to provide a an extraordinary computing resource to climate science. 369 00:39:47,650 --> 00:39:48,880 And if any of them are here in this room, 370 00:39:49,090 --> 00:39:56,690 then I'm very much hoping that one of our heroic board moderators who keeps an eye on all the rest of the participants is here. 371 00:39:56,710 --> 00:39:59,770 So if Mo is here, thank you very much indeed for all your work. 372 00:40:00,430 --> 00:40:02,500 I nearly fell off the dice at that point. Okay. 373 00:40:02,620 --> 00:40:08,530 So this is just some evidence of the models working, but in view of the time, I can I ask you to take my word for it. 374 00:40:09,450 --> 00:40:13,540 And but some evidence, more interesting evidence of the models not working. 375 00:40:14,200 --> 00:40:26,920 If we look here at the sorry, the models models, simulated temperatures and observed temperatures over the same period in time. 376 00:40:27,190 --> 00:40:32,140 You'll notice we have many more models and observations because we are, of course, able to run the model many, many times. 377 00:40:32,650 --> 00:40:38,260 And there's an obvious bias between them. Even though we haven't got that many observations, we can see the models too warm. 378 00:40:38,470 --> 00:40:43,750 It's over. It's too too far to the left. I think that's typical for these kinds of models. 379 00:40:44,080 --> 00:40:49,900 And we have to in this particular study, we can't do anything else but just correct that bias. 380 00:40:50,290 --> 00:40:54,460 What we would rather do, of course, is use a better model which doesn't have that bias. 381 00:40:54,820 --> 00:41:02,350 And we're hoping working with collaborators here and also ECOWAS, to move on from the relatively crude models we're using here, 382 00:41:02,560 --> 00:41:07,090 to use the most sophisticated models available to redo this kind of analysis. 383 00:41:07,330 --> 00:41:17,620 But at this point, all we can do is correct for these biases and see what happens and use our models to assess how the risk of an extreme heat wave, 384 00:41:17,620 --> 00:41:22,000 such as happened in 2010 in Russia has changed over the years. 385 00:41:23,110 --> 00:41:29,769 And what we find is quite an interesting it's quite an interesting conclusion because we can kind of say that both of these papers, 386 00:41:29,770 --> 00:41:32,980 which appeared over this year, are, in a sense, right? 387 00:41:34,150 --> 00:41:40,510 It just depends on how you frame the question of how much of that event was anthropogenic 388 00:41:40,510 --> 00:41:45,490 or how much of it was externally driven versus how much was an internal fluctuation. 389 00:41:46,510 --> 00:41:53,979 This plant shows the return time of monthly temperatures as simulated by the model after bias, 390 00:41:53,980 --> 00:42:02,620 correction and so forth in the 1960s in green here and the 2000s in blue. 391 00:42:03,050 --> 00:42:06,520 Okay. So these are preliminary results. 392 00:42:06,730 --> 00:42:12,120 And, you know, there's still work to do to work out how uncertain we are in these curves. 393 00:42:12,280 --> 00:42:15,280 But they do serve to illustrate an important point. 394 00:42:16,060 --> 00:42:22,060 The heat wave was a big departure from average conditions whichever decade you were looking at. 395 00:42:22,450 --> 00:42:26,050 Okay, so six degrees above normal of which. 396 00:42:26,350 --> 00:42:34,150 So that's this big black arrow here, of which maybe only a degree was due to the background warming. 397 00:42:34,900 --> 00:42:40,450 Okay, so on that way of thinking about the problem, the heat wave was indeed mostly natural. 398 00:42:41,500 --> 00:42:44,809 Okay. So be careful. Now, watch. 399 00:42:44,810 --> 00:42:52,670 I'm not. This is the conjuring trick. Okay. On the other hand, if we think in terms of the probability of the heat wave occurring. 400 00:42:54,590 --> 00:43:04,820 This was the magnitude of the heat wave itself. This threshold here in the 1960s, it would have been a one in 100 year event. 401 00:43:05,810 --> 00:43:10,310 But by the 2000s, it was down to a one in 30 year event. 402 00:43:10,730 --> 00:43:18,230 So it had become three times more likely to occur in terms of its probability of occurring in 2000. 403 00:43:18,530 --> 00:43:24,770 Most of the risk of it occurring at the time it did was due to the external trends. 404 00:43:25,820 --> 00:43:30,620 So you got one event. If you think about it in terms of magnitude, it was mostly natural. 405 00:43:31,040 --> 00:43:35,270 If you think about it in terms of probability, it was mostly driven by the external forcing. 406 00:43:35,690 --> 00:43:45,050 Okay. Now, that's not a convenient conclusion for a reporter to take away, but it's just the way it is, I think. 407 00:43:45,620 --> 00:43:50,540 I don't think anybody saw me attempting to explain this to Emily Maitland on NEWSNIGHT last week. 408 00:43:51,380 --> 00:43:55,040 It did not go well, although actually in self-defence. 409 00:43:55,220 --> 00:43:59,120 The dice, it was it was my fault, not the dice for the dice. She did a very good job. 410 00:43:59,120 --> 00:44:05,330 It was the it was it was me fluffing my lines over what to say because the dice did actually roll six more often than she had done. 411 00:44:05,570 --> 00:44:09,110 But okay. Never mind. But she thought that she'd roll six every time. 412 00:44:09,110 --> 00:44:14,450 But that's that's the problem we always face. People think if it's global warming, we should get a heatwave every summer. 413 00:44:14,780 --> 00:44:19,310 So anyway. Never mind. I guess that's a feature of NEWSNIGHT, isn't it? 414 00:44:19,340 --> 00:44:24,530 You always realise what you should have said as soon as the microphone goes off. Anyway, so. 415 00:44:25,190 --> 00:44:29,030 But there we are. So, so. So this. I've got a little bit more time to explain this to you here. 416 00:44:29,240 --> 00:44:34,280 So that's that's the situation we're in, which is the question we're more interested in the magnitude. 417 00:44:34,460 --> 00:44:39,710 How much is human influence increased the risk of a heat wave of a given magnitude? 418 00:44:40,790 --> 00:44:42,800 So these are two ways of thinking about it. 419 00:44:44,780 --> 00:44:52,100 There's a sense in which it was mainly natural in terms of magnitude or a sense in which it was mainly caused by the external trend. 420 00:44:52,250 --> 00:45:00,710 If you think in terms of occurrence probability, I think it's not really a scientific question, which is the right way to think about it. 421 00:45:01,580 --> 00:45:05,960 I'm afraid Sam is nodding at this point because I'm you know, I'm aware that, you know, 422 00:45:06,260 --> 00:45:11,390 we scientists tend to tend to think that we know how to answer those kinds of questions, but we don't. 423 00:45:11,570 --> 00:45:17,550 It depends who's using the information, which which question they will they will be most interested in. 424 00:45:19,340 --> 00:45:28,680 We are able to do this using the weather at home approach, using these large ensemble simulations to large numbers of different events. 425 00:45:29,510 --> 00:45:37,610 And it's important to stress that as we're looking at the impacts of large scale warming on events in different parts of the world. 426 00:45:38,480 --> 00:45:41,960 Not all events are being made more likely you often will get. 427 00:45:42,320 --> 00:45:45,790 It's often said climate change is making the weather more extreme. 428 00:45:45,800 --> 00:45:47,230 I'm never quite sure what that means, 429 00:45:47,990 --> 00:45:55,250 but it's certainly not true that every kind of extreme weather event is being made more likely by more likely by climate change. 430 00:45:55,880 --> 00:46:05,990 Here's to the floods that occurred in North in 2000, which we reckon were made somewhat more likely as a result of past greenhouse gas emissions. 431 00:46:06,860 --> 00:46:12,739 And this is an interesting result from Alison K in C H Wallingford, where she looked at a a flood. 432 00:46:12,740 --> 00:46:16,400 That didn't happen in the spring of 2001. 433 00:46:17,000 --> 00:46:21,200 Okay. So this sound doesn't slightly academic, doesn't it? 434 00:46:21,200 --> 00:46:27,200 But it's an interesting question. We didn't have a flood in the spring of 2001, but we might have done. 435 00:46:28,190 --> 00:46:33,350 And the risk of having one was substantially reduced by human influence on climate. 436 00:46:33,920 --> 00:46:40,910 Because why in spring, the big floods that happen tend to result from accumulated snow melting fast. 437 00:46:41,210 --> 00:46:46,980 That doesn't happen anymore because we don't get those sorts of accumulations of snow again. 438 00:46:47,810 --> 00:46:51,740 So this kind of thought it was completely academic because this kind of part has happened in the past. 439 00:46:52,010 --> 00:46:57,440 Back in 1947 and 1963 and those kinds of flood, the floods are becoming less likely. 440 00:46:58,190 --> 00:47:04,790 So when you're making a statement about human influence on flood risk in the UK, 441 00:47:05,000 --> 00:47:08,899 I'm always careful to sort of preface this with a sort of British Rail style. 442 00:47:08,900 --> 00:47:16,190 It's got to be the right kind of flood. Okay, so this is why we've argued we need this sort of work. 443 00:47:16,190 --> 00:47:21,200 Probabilistic event attribution. Most present day impacts of climate change are related to extreme weather, 444 00:47:21,410 --> 00:47:26,930 and quantifying how risks are changing does allow us to better quantify and indeed insure against present day risk. 445 00:47:27,830 --> 00:47:32,719 It allows us to build resilience and also to justify that adaptation funds are really 446 00:47:32,720 --> 00:47:36,590 spent on adaptation to climate change and not just building resilience to bad weather. 447 00:47:37,700 --> 00:47:46,070 There's been some criticism of this idea that I'm going to skip over that to the just in view of the time, 448 00:47:47,030 --> 00:47:50,330 just to show where it gets it gets really interesting. 449 00:47:51,200 --> 00:47:55,970 And this is sort of tends to be the point where juices get. In this debate. 450 00:47:56,870 --> 00:48:03,830 And this is a quote not from a scientific paper, but from a paper in the Columbia Journal of Environmental Law by David Grossman in 2003. 451 00:48:04,370 --> 00:48:13,279 And he pointed out that for lawyers, it is the contribution to risk way of thinking about the problem that matters, 452 00:48:13,280 --> 00:48:22,970 not the magnitude and the threshold. For lawyers getting interested in the possibility of liability is an increase in risk of roughly a factor of two. 453 00:48:23,960 --> 00:48:31,280 Now, of the events we've been talking about, the European heatwave in 2003 exceeds that threshold. 454 00:48:31,820 --> 00:48:34,220 The UK floods of autumn 2000 probably don't. 455 00:48:34,580 --> 00:48:40,880 So if you're thinking of suing an oil company for your house being devalued, you probably well, you probably don't want to talk to me. 456 00:48:42,290 --> 00:48:47,840 You'll have to find another expert witness for that one. And we're still working on the 2010 heatwave. 457 00:48:49,400 --> 00:48:53,960 What does this mean and where might all this go? I'm at present, 458 00:48:55,040 --> 00:49:01,880 people have started raising the question of whether victims of climate change could secure compensation 459 00:49:02,120 --> 00:49:08,030 as a matter of legal rights rather than simply because they're poor and they're entitled to some help. 460 00:49:09,980 --> 00:49:15,020 And the main of the main obstacle in these cases, most of which have been filed in the states, 461 00:49:15,020 --> 00:49:18,320 of course, is the political crisis, the political question. 462 00:49:18,560 --> 00:49:24,620 The point is there is a political process going on. The courts are therefore reluctant to get involved in assigning liability. 463 00:49:25,670 --> 00:49:30,290 But what if and this you know, what if that process in the next couple of weeks, for example, 464 00:49:30,470 --> 00:49:40,250 were to collapse completely and we were to sort of emerge from Durban with sort of politicians 465 00:49:40,250 --> 00:49:44,900 simply giving up and saying that they were just not going to they couldn't reach agreement. 466 00:49:45,470 --> 00:49:52,340 As indeed, people have wondered if this might happen on a number of occasions through the process so far. 467 00:49:54,440 --> 00:50:00,530 The total cost vary. Lots of, you know, where how far might liability extend? 468 00:50:00,950 --> 00:50:02,960 What sort of numbers are we talking about? 469 00:50:03,230 --> 00:50:10,640 If fossil fuel producers and this is why it's good to have David home from Shell on the panel to talk about this. 470 00:50:10,850 --> 00:50:19,460 If fossil fuel prices were actually be to be held liable for the climatic consequences of the products they sell, how big might the bill become? 471 00:50:20,450 --> 00:50:21,020 Well, it's interesting. 472 00:50:21,170 --> 00:50:28,050 The estimates that are available suggest the bill, which is not that different from the size of carbon taxes people are talking about. 473 00:50:28,670 --> 00:50:37,010 So it might not in the end, it could wash out in a very similar way to an imposed carbon tax. 474 00:50:37,190 --> 00:50:41,100 But this is the kind of thing I would hope we will get talking about in the panel discussions. 475 00:50:41,120 --> 00:50:47,280 I won't dwell on that. Are those those numbers here? I'm a puzzle, though. 476 00:50:47,640 --> 00:50:53,460 Each time I just want to leave you with is that most environmentalists, I'm confident, 477 00:50:53,820 --> 00:51:01,530 would object strongly to the idea of resigning ourselves to a future where fossil fuel producers and and those who benefit 478 00:51:01,530 --> 00:51:08,250 from the use of fossil fuels simply pay their way and compensate people who are adversely affected by climate change. 479 00:51:09,210 --> 00:51:13,620 And yet, so so although environmentalists would typically say this would be a bad outcome, 480 00:51:14,970 --> 00:51:22,410 and yet ask yourself, which you think would have more impact on the share price of a major coal company? 481 00:51:22,710 --> 00:51:28,920 And remember, coal companies have on their books far more carbon than we can possibly afford to dump in the atmosphere. 482 00:51:29,070 --> 00:51:33,570 If we're actually going to meet the targets, the politicians say we're going to meet in avoiding dangerous climate change. 483 00:51:34,930 --> 00:51:40,360 If an an if a deal was announced in Durban that we were actually going to set up a global cap and trade system, 484 00:51:41,470 --> 00:51:44,530 would that actually affect the share price of a major co-producer? 485 00:51:45,340 --> 00:51:50,469 My guess is it would not. The share price wouldn't even flicker because people know that the politicians will 486 00:51:50,470 --> 00:51:55,360 never have the bottle to actually see it through and keep that carbon underground. 487 00:51:57,100 --> 00:52:02,860 On the other hand, if Durban works to collapse completely and it to be announced that as of now, 488 00:52:03,070 --> 00:52:09,700 anyone handling fossil fuels was fully liable for all the consequences that they have on the climate for the indefinite future, 489 00:52:10,000 --> 00:52:13,180 that actually might make a bit more of an impact on share prices. 490 00:52:13,960 --> 00:52:22,270 And that suggests we're revealing what we really believe about both the capability of the political process to deliver as it's going at the moment, 491 00:52:22,630 --> 00:52:28,450 and the potential of private sector remedies to have more impact in the future. 492 00:52:29,350 --> 00:52:34,990 The real the reason for this asymmetry is the point that under the second scenario, 493 00:52:35,440 --> 00:52:39,969 it's those who benefit from the production and use of fossil fuels today that 494 00:52:39,970 --> 00:52:43,960 bear the risk of climate change turning out to be worse than currently expected. 495 00:52:45,070 --> 00:52:53,649 So as of next week, the world's attention on this issue will be focussed on Durban and gathering of scientists 496 00:52:53,650 --> 00:53:00,280 and politicians to discuss how they're going to negotiate their way out of climate change. 497 00:53:00,520 --> 00:53:09,580 What many fewer people will know is that another event happens on Monday, which is all the testimony begins in the case of Kivalina versus ExxonMobil. 498 00:53:10,360 --> 00:53:17,589 Kivalina being an Arctic village that is suing Exxon Mobil for the products Exxon Mobil sells, 499 00:53:17,590 --> 00:53:24,280 causing global warming and resulting in the village essentially sliding into the sea. 500 00:53:25,960 --> 00:53:29,650 I have no idea what the outcome of Kivalina versus Exxon Mobil will be, 501 00:53:30,040 --> 00:53:36,429 but I suggest to you that the Ninth Circuit Court in California is where our attention 502 00:53:36,430 --> 00:53:41,080 should be focussed next week and not the intergovernmental negotiations in Durban. 503 00:53:41,530 --> 00:53:41,890 Thank you.