‘Climate Change: Science and Policy’ Lecture by Mario Molina, Nobel Prize in Chemistry

[Music] thank you very much for your kind introduction I'll be talking about climate change science and policy aspects of it but I will spend a few minutes first just talking about stratospheric ozone what led to the Nobel Prize that I was rewarded with it was of course a huge honour to to receive it I I should just say I gave a similar lecture yesterday I know there are just a couple of you that heard me already I thought I could give a different lecture today but the only way I could do that is if I give it in Spanish so I apologize but I'm actually going to use the same or similar view graphs so if what I want to do is to put in context the the research that I carried out with my colleague sherry Rowland we were at the University of California at Irvine this was in early 1970s and at that time I had just finished my PhD at the University of California Berkeley but I have met shell Roland already because we were both doing very fundamental research on chemical reactions trying to understand chemical reactions at the very fundamental level using quantum mechanics and so on and so forth but we both decided when I came to work with him to work on something that was a little bit closer to some societal problem to something that which we could apply these fundamental science understanding that we have developed and so we decided to learn about the atmosphere to the atmospheric chemistry which at that time it was not a very well-developed discipline we had a few colleagues that we had made that we're working on that but what we decided let's work on how do we do that let's work on a problem that we think it's interesting out of sheer curiosity see whether we can solve it and in that way learn about how the atmosphere functions particularly some of its chemical properties so that's how we started let me give you sort of a little bit of the background and this is going a little over the century ago how electric refrigeration became became to be of course very common very useful first in developed countries but then eventually everywhere and that's using electrical refrigerators now some of you might know before that how did people deal with refrigeration because that was already in use in the nineteenth century but it was typically only more wealthy people but there was a big industry that had been developed the way it worked is by importing large chunks of ice from frozen lakes at northern latitudes that's a way refrigeration work before the electric refrigerators came on board and so it was maybe easier to have refrigerators here at these latitudes and it was in Southern California or in Mexico okay but that's what nevertheless this worked very well how does a refrigerator work what you need a refrigerant which is a fluid that with medicinal electricity with an electric motor you can compress it as a liquid and then you make this liquid move through the freezer and evaporate as it evaporated cools and then the gas at is formed you compress again to form a liquid and so on so it's a very simple idea there are other ways to do that but this was a very effective way what it had a problem namely that the refrigerants that were in use originally were sort of nasty chemicals sold for dioxide and ammonia and so there were the number of accidents went home refrigerators broke down and leaked and people had to breed these gases that was of course it led to some accidents and so chemists developed new chemicals they were called at a time miracle chemicals that could be used as refrigerants but in some way not poisonous and so the chemical industry developed is so called chlorofluorocarbons you can see here the formulas but the important thing about this chemicals is that they are very inert very stable they also evaporate and so they can be used as refrigerants but you can breathe them they're so inert that they don't change you can breathe them and nothing happens as early as opposed to ammonia and because of that they could be used also as propellants in spray cans which you certainly cannot have something like sulphur dioxide yeah because it would be a little stinky ok but also very harmful and spray cans became very popular particularly in the United States because the Inglis many things were sprayed from toothpaste cleaners and so on and so that's how this problem arose because we had them a coalition Lovelock who had developed a very special instrument an electron capture gas chromatograph and he was able to measure the presence of this CFCs these refrigerants in the atmosphere I turns out not just in the northern hemisphere but even in the southern hemisphere for they were actually not produced but clearly these compounds were mixing all over the planets that's why we have a global issue with this with this compound well I'm not going to give you a lot more details other than Cheryl Rowland and I then decided to investigate what's the fate of these compounds in the environment and we realized they were very stable and they were going to eventually to diffuse into the stratosphere that's a layer above the troposphere the lowest layer that we have in the atmosphere at sufficient altitudes so that just like molecular oxygen or co2 that we all know at high altitudes solar radiation of very short wavelengths breaks the molecule apart and making oxygen atoms so the CFCs at sufficiently high altitudes would also break down and release chlorine atoms and what we then sort of postulated because we knew that from the elemental chemistry is that chlorine atoms react very fast with ozone and the product chlorine oxide reacts again so you recover the chlorine atom so the bottom line is that we have a catalytic cycle the single chlorine atom which is recovered deployed with this mechanism can destroy tens of thousands of ozone molecules and what Saul zone ozone is warned again by this breaking molecular oxygen but it makes this layer the ozone layer in the stratosphere 30 to 50 kilometers sort of above the surface mainly but it shields us from short wavelength radiation that comes from the Sun that is very harmful to a number of living creatures but among others ourselves humans if you get the short wavelength radiation your skin it breaks down DNA there are some repair mechanisms but sometimes they don't work well and you get skin cancer so that's one of the issues that that happened if you affect the ozone layer and so that was our theory but we based it our colleague Paul Crutzen with whom we shared the Nobel Prize he had earlier sort of discovered or or suggested how the natural ozone layer is controlled and that's with natural amounts of nitric oxide with a similar catalytic mechanism and so we were able to also work with him and with the other members of the scientific community that knew others were working on the stratosphere and essentially it appeared that the science was well understood and that's why we then published a paper in Nature suggesting that the release of chlorine atoms would eventually be pleat this ozone layer and that it's something we should try to avoid not together a large hell problem for humanity and for all the species as well but it turns out although we had not anticipated it early on but over Antarctica something very special was happening so something very spectacular namely only over Antarctica in the spring months which is September October at all in the southern hemisphere the ozone layer was beginning to be affected not in the first few years which was in the 1970s when we first came up with these theories but in the 1990s now we understand why because it's a very nonlinear effect I won't bother you with the details of the chemistry but it it's two chlorine monoxide molecules reacting with each other so the effect is proportional to the square of the chlorine concentration but what happens you can see here is an in a matter of weeks over Antarctica in the spring months and again only starting in the 1980s not before that also was disappearing but quite fast and in altitudes where it's not only most abundant more than 98 99 percent of the ozone was reacting away so that's what we now label the ozone hole and over the Arctic it something happens for not quite as dramatic we now understand why because Antarctica gets much colder because the topography of the planet works in such a way that the polar vortex is much more stable in the south where you have a continent of high-altitude was surrounded by flat oceans whereas in the North it's the other way around you have a flat ocean which is normally ice surrounded by continent so the vortex is not a stable and the bottom line is an Antarctic is a place for the stratosphere and in fact anywhere close to the surface is at the lowest temperature minus 80 degrees Celsius or so and we also now understand how the chemistry from ice particles formed that accelerate is the structure so the science became very well-established we had some measurements that indicated really with with with a lot of confidence that it was indeed indeed the CFCs that were causing this problem and not a natural effect but what was particularly encouraging is that we started even before the ozone hole was there we started to work with not just with the scientific community but trying to communicate this problem to society because I remember sherry and I sort of asking ourselves what should we do now that we face this global problem that might have some social consequences consequences for society if not us who if not now then when so we went all out and communicated that most importantly to decision makers in government to the public in general and eventually also to diplomats and fortunately we were able to convince heads of state and through the United Nations an agreement was reached the Montreal Protocol and which practically all the nations in the plan it's agreed to stop manufacturing these chemicals and by that time the chemical industry very much agreed with us as well and they were producing other chemicals that we now use as refrigerants you don't have to use CFCs anymore and because of the Montreal Protocol we now know that the ozone layer is recovering it's a slow process because the CFCs are still damaging this the stratosphere those that were emitted in the 20th century because they remain in the atmosphere for many decades but clearly measurements are indicating that the ozone layer is already recovering so we have a very big success story with this issue so let me now switch to climate change and I'm going to start the gate putting this in context with sustainable development which is as you can read it here it's it's development that meets the need of the present without compromising the ability of future generations to meet their own needs that was grown by the West Brundtland Commission is prominent in prime minister in in in Norway at that time and what I would just correct now is that sustainable development nowadays also means worrying about our own generation because we're already seeing happening not just problems for the future but problems that are affecting us nowadays and before I start with time a change give you some indication that there are many other problems as scientific community has identified at least eight or nine problems that they call parts of the planet boundary namely issues that affect the entire planet that we should be worrying about but what is interesting is that if you look at Industrial Development you look at the how particularly because technology advanced a lot it is in the second half of the 20th century that industry really suddenly began to develop very fast and one of these issues is the release of carbon dioxide which results from burning fossil fuels and but this is a consequence of all these changes in economic terms population GDP fertiliser consumption paper production what-have-you at least the all these issues there's something peculiar that you can see that these curves Bend and that's why this is called the great acceleration starting roughly 1950 okay and these are the changes that worry us why are we go into the environment where suddenly we were affecting the ozone layer that's one thing we have dealt with but many other problems we have not dealt with climate change being perhaps the main one but because of these changes our colleague Paul Crutzen in particular has sort of put on the table this issue that we are in a new geological era which is called the Anthropocene ok we're no longer live in a geological earrin like the past where the changes had to do with periodic changes perhaps in the Earth's orbit that causes ice ages or large volcanoes erupting or what have you the the big changes nowadays clearly come from human activities hence the name Anthropocene okay yeah and one suggestion is that this new era really starts around 1950 because of this acceleration that I just pointed out anyhow there are that issues besides climate change such as the nitrogen and current and forceful recycles one very worrisome one has to do with with with species disappearing okay from so we have a historically something like five big extinctions for many biological species disappeared because of some something big happening like a large meteor landing somewhere close to none to the Yucatan Peninsula in Mexico and that's what killed the dinosaurs so some huge events happened in the past but now we have the entropic scene and it's one important cause for this biological disappearance of many important species but I will not be talking about this other issues let me concentrate on just climate change and I'll do that by talking about these three myths these are three points in which there is some misunderstanding misunderstanding particularly by the general public but also by many politicians the first one is the idea that all climate is very complicated so maybe some scientists think that something is happening or we should worry about the climate but many other scientists believe that's just natural climate after all has changed in the past so it's not clear that it's due to human activities that's a myth why because surveys have been carried out very explicitly really measuring what the experts think not what people in general or live in the scientific community in general for people that work in some way whose scientific work is connected with climate change they've published papers and the vast majority agrees climate change is certainly taking place and it's different from the changes that we have had in the past and it's most likely the consequence of human activities so that's what is very well-established and such we show this I like to expose that when these surveys were done there were there was this 3% of skeptics if you want it's not the right word because we all scientists are skeptics we don't accept a new thing in in science until it's very well corroborated science after all goes with with measurements and with reasons ok with the scientific method where the you sort of established whether something is happening or not based on experiments that they reproduce it will and so on and so forth what that has already happens with climate change science so there are no good explanations of what's happening today other than the accepted science and the point is we understand very well what the objections are from this 3% of now smaller I believe of scientists that really question this what I insist there are many scientists that still don't believe in this but because they are not experts and have not looked carefully that's what's going on what I like to point out one of the main ways in which the non scientists or scientists in different specialties or politicians they point that all something must be wrong with climate science they don't take into account that climate is a complex issue just like the human body ok we are complex and that's why medicines don't work 100% of the time because we're some of us are different and so you have to talk about probabilities and so on and so forth and you might have sometimes a very good theory what things remain to be explained the same thing happens with climate not all aspects of climate are perfectly well understood the role of particles for example there are still some questions there the role of clouds show exactly do they compensate for climate change these are things which require additional science research to be carried out but it's in general well understood what the object the people that object sometimes they do what we call picking they find something wrong one aspect I mentioned two possibilities but that there might be some measurements that were questionable or what-have-you and they somehow or other make an analogy that the science of climate change is like a house of cards and if you find one card somewhere that doesn't quite fit remove it the whole thing falls apart that's cherry-picking that's not the way science works it's more like this like a puzzle and we have pieces of the puzzle that we still have to fit together but you can more or less figure out what's there which is not a very sort of harmless little kitten movie so the bottom line is that the science is very well-established and so I'll tell you briefly a little bit about the science itself I'm not going to have time to go into much detail but first I want to highlight we are talking about a global problem and it's a problem with the atmosphere which you cannot see because the atmosphere is transparent but it's also very thin I like to make the analogy it's like the skin of an apple because most of the atmosphere is is that close to the surface above 50 hundred kilometers it becomes so thin that people can affect climate in any significant way anymore but if you release some chemicals like carbon dioxide or CFCs that are both very long-lived carbon dioxide in fact it has been measured that some fraction of it remains more than a millennium before it somehow or other gets absorbed again at the surface we and so the half of the carbon dioxide that disabilities absorb relatively rapidly but the good fraction of it remains in the atmosphere for a long time and the CFCs that's goes back what original findings remain many decades before they can get into the stratosphere anyhow because mixing within each hemisphere takes place in on a time scale of a few months that's why we talk about global problems because it doesn't matter where these gases are emitted they mix it throughout the entire planet and the stratosphere the also layer there covers the entire planet and the climate even though it varies of course its consequences are local we're talking about global climate when we're talking about these issues that that's the problem but what is what's happening well let me just explain very briefly here the following reasoning that was already what scientists were dealing with in the nineteenth century the question at that time was how does the climate of our planet come about to be and the reasoning was look we can measure how much energy does our planet receive from the Sun and that's what is keeping us warm and we know from physics and from from some of laws of thermodynamics what have you without going into detail but already for millions of year our planet is in thermal equilibrium namely it absorbs energy from the Sun but it emits the same amount of energy it receives it's no longer accumulating energy there are some energy inside the planet put it it's very well insulated from the surface so it doesn't affect climate fix except when you have huge volcanic events ok so here in this graph we have a plot of this energy in the which it comes in the form of electromagnetic radiation visible radiation our eyes evolved to see light from the Sun and at what shorter wavelengths is infrared radiation which is how our planet loses but the same amount of energy and do you know of course that warm bodies emit radiation we can measure a lot in the lab and as you increase the temperature eventually they can become red-hot that's when they begin to emit some visible radiation already very warm and white hot like in incandescent bulb then it's relief very high temperatures and the son of is of course one of this very high temperature but fortunately were not that warm that's why life could evolve and infrared light emitted by the our planet is not visible and so you could measure that in the laboratory and measure the dependence of these energies on temperature and the answer that was first obtained by doing this balance is that our planet should be at around minus 18 degree Celsius that would be a frozen planet we wouldn't be here so that's not the case just to explain that this initial finding of what the temperature was was wrong because the atmosphere however thin it is functions as a blanket and this blanket keeps some of this radiation coming from the surface area as I explained in a minute but I forgot I wanted to first explain this is just a little bit aside the issue but very interesting one that these measurements that were carried out could not be explained early on in terms of how much infrared radiation the bodies emit in the laboratory or a planet in space and it was Planck Max Planck that was able to rationalize these equations and and explain them in physical terms and that's what I have in this viewgraph this is Planck and that's the law that he was able to explain how by inventing nothing less than quantum mechanics you can only explain those observations by assuming that energy comes in packets light comes in packets as well called photons that Einstein also helped with that so this revolutionized physics of course always said physics now and the chemistry is quantum chemistry nowadays biology and so on we had an enormous change in the sciences that towards the beginning of the 20th century what this this all only partly sort of effects the way we understand the climate because it was after all already well measured in in the in the laboratory but the point is the following that it we do have a blanket how does this blanket function if you look at three these three are roses energy coming from the Sun one of those roses does not absorbed by the planet is reflected by clouds or by the surface you can have light surfaces like snow or ice or you can have deserts like the Sahara Desert they reflect light but about two-thirds of the energy that comes from the Sun gets all the way to the surface and the atmosphere is transparent except for the clouds of course that reflected is transparent to visible radiation so it makes it all the way to the surface but then I was explaining that at the temperatures that we have the surface then emits in principle it would be the same amount of radiation except that we do have this blanket and because the atmosphere absorbs this infrared radiation it has to emit about twice as much because in the atmosphere absorbs it then yttrium it's this radiation absorbed the molecules in the atmosphere absorb it then they remit this energy in all directions roughly half upwards half downwards that's why you have to the surface has to meet about twice as much half of that comes back to the surface warming it up and the only the two remaining arrows is what goes out to space and so in principle you are not accumulating energy anymore that's it has already reached equilibrium long time ago but this explains very clearly how this blanket functions okay that's the Green has the natural greenhouse effect just one more piece of information interesting with Jason and atmospheres mostly nitrogen oxygen and a little bit of argon just about 1% of argon which is an inert gas and these gases are all transparent not just to visible radiation but also to infrared so it turns out it's only the tiny amount of gases whose molecules have more than two atoms like water vapor h2o of course you know co2 and a few others like the CFCs these are the gases that to absorb infrared radiation and then give it the property of of a blanket water vapor absorbs about 3/4 of the radiation emitted by the surface and carbon dioxide most of the rest but there are these other gases besides the CFCs there's methane and there's nitrous oxide but the point is it's only small amount they are measured in parts per million levels the amount of co2 that you would have if it were the soot condensed rather than in the gas phase would just be a 4 millimeter thick dry ice and that's what keeps the our planet nothing less than 33 degrees warmer then you would have in the absence of these gases that's the natural greenhouse effect but something else happens the amount of water vapor depends very much on temperature it condenses water evaporates from the ocean as it goes to higher altitudes the temperature drops and the water in the atmosphere as originally as a gas as a vapor condenses to make clouds rain snow and so on so if the point is the following its carbon dioxide although it's it's responsible for only the remaining 1/4 of this balance if you were to remove carbon dioxide the atmosphere would begin to cool and water would condense and here is what would happened clouds you would get a lot more of the water vapor condensing coming back to the surface and you would get a frozen planet so carbon dioxide is the thermostat of the planet and that's very well explained also in geological timescales for ice ages and and so on it this is sort of I just give gave you a brief glimpse of the physics and of a natural climate okay just to emphasize a bit well understood but now let's see what humans have done and here we look at this graph when we have carbon dioxide for the last ten thousand years which is the Holocene that's the geological time scale in which human civilization has really advanced that's when agriculture was on the run so on and so forth before you had ice ages and more complicated climate that was not you you had hunter-gatherers before that agriculture just came in this time period and for this time the carbon dioxide amount was less than 250 parts per million and if you go back even millions of years has was always around those levels and suddenly on this timescale it jumps and it's now at least 40 percent larger and this carrying it's not long before it's going to be twice as large as this has been for millions of years what's happening that's because you're burning fossil fuels for do the fossil fuels come from that's from photosynthesis you remember the cycle you have oxygen in the atmosphere and carbon dioxide as well and water vapor and green plants can take carbon dioxide water vapor in the plant itself through photosynthesis it makes food carbohydrates that we can eat and as we eat them we can use them to generate energy how they get oxidized and this chemical energy is what we can use to walk to run and and so forth and what's the result of that oxidation it's you get back the oxygen and water vapor without photosynthesis we would have run out of oxygen well this extra co2 comes from photosynthesis but that took many millions of years to take place and those plants some of those will be composed but below the the Earth's surface giving you coal or petroleum from oil okay so that's a there are a lot of details known about that but that's what happened and if if we see what's been happening to temperature not easy to measure but it's very clear that you have a similar jump just in recent years the temperature has jumped about one degree it doesn't look like much but we're talking about this average surface temperature of the planet which doesn't change very much with time if we have a little cooling from the year eight for the eight thousand years ago that might have continued put long before we get a nice ice age that might take several tens of thousands of years if we were to continue that way and suddenly we jump upwards to a temperature that we haven't seen for a long time okay for for tens of thousands of years and of course the question is given all this explanation about the signs of the climate they should be connected but how do we evaluate that and one way to do that is there's a group of scientists they get together there are voluntary scientists and about every five years they published a report that's it Intergovernmental Panel on Climate Change the IPCC they write a report summarizing the science and their conclusion is that indeed we're not quite sure that the temperature changed this caused by co2 we only can do that can make statements in terms of probabilities and the probability with the last report claimed by this group is about 95 percent so some possibility that that time that is changing just because by chance 5% probability but the most likely thing is that it's indeed caused by human activities okay so that's the science itself but let's look at the next myth namely that we shouldn't worry about this this is just something that our children's perhaps our grandchildren need to be concerned with because climate changes very slowly well that's not really the case the Arctic sea is already melting okay and more much more worrisome perhaps is that we have extreme weather events heat waves that are already killing many people and we have also here against floods and droughts and wildfires and so on and in the United States in particular we saw last year 2017 economic losses of the order of 3 to 4 billion dollars just caused by these events that we call the extremes climate extremes ok and if we do the statistics just law review here there are many more but they are all increasing so what science have to tell us about this science very cautiously but nearest 10 15 years ago say well that's why I don't ill we have good enough statistics but now it's very clear there is indeed a connection and the connection is probabilistic this weather events were not caused by climate change you would still have hurricanes that have happened for some time now what is the intensity of this event that's why we call them extreme events that has very clearly increased as a function of time so that that so much for that means but the last is a very important one why should we worry about fossil fuels they are so important for the economy we cannot really touch that because that's how what our economies depend on fossil fuels well that turns out to me to be a myth as well because now we have other ways to generate energy of course electricity now it's it's well known this is relatively recent just in recent years the technology has advanced to such a degree that now these forms of energy wind and solar are competitive in economic terms with fossil fuels of course it's difficult to change society that's one of the difficult for them to change fast because investments have already been made but the point is that we can already do it and we don't need to to sacrifice economic growth and this sort of energy forms also generate a lot of jobs and so on so there's no longer an excuse that you need to subsidize this change it is economically competitive ok of course there are still issues that require further technological development such as these are intermittent so of course solar energy only works in the day not at night wind energy sometimes doesn't work but there are lots of technological advances storing this energy and that there are already some that are working and many more that are being developed so we can do it and the question then is what has the world done about this which is perhaps the most serious challenge that society's facing certainly the most serious environmental challenge but in terms of what might happen in the future and good news is that to begin with we had a meeting which is organized by the United Nations these are so called the conference of the parties already in 2009 I was there in Copenhagen and there were more than 120 heads of state at that time and they all agreed there was consensus we need to do something about climate change heads of state all agreed all over the planet and one way to sort of condense these these goals what to say let's agree that the temperature of the planet we should try to keep it from rising two degrees it should hopefully rise less than two degrees Celsius I remind you we're already halfway there and even if we were to stop emissions now because the planet is not yet in equilibrium that temperature would continue to rise for a while so we're not that far but that's what the heads of state agreed but not unfortunately the people actually doing the the rules the negotiators did not agree so not much happens in Copenhagen what we kept working very hard and finally in December in the in the 2015 the Paris agreement came about all heads of state I was there in fact this time more than 150 they all agreed to reach to try to reach this goal to begin with perhaps not with measures the strong enough to to really reach the degree but each country coming up with voluntary measures to reduce their emissions and we the idea that they would meet again in five years so in a few years that will happen to explain what else needs to be done so that the climate doesn't keep changing okay and of course it's going to be measured and so on and so forth so that's an incredible achievement which means it's just like a Montreal Protocol but it's only halfway I need it's only on its way but here is what's happening if we look at the missions as a function of time we see that the two degrees line is the blue line we are not there yet we will have to reduce emissions mode for dramatically the Paris Accord is sort of half way if we do only the Paris Accord we might get all the way to three degrees who knows what if we do nothing that's a big worry that's the red line we could reach three or five degrees okay and so what should we do there's another very big worry here in the United States there are many states California Massachusetts and that's very much agree with this but not the central government president Trump as you know didn't does not want to remain on the Paris Accord because he does not believe in climate change wow that's a big worry let me just tell you what does that imply and so I'm going to show you Eustace roulette which is one way to explain that to the public you don't have to be a scientist to understand this and this came out of the MIT group I was many years at MIT to work with this group at the global change Center they have a very large one of the most complete models of the climate of the of our planet which is coupled to a very large model of the of the economy of the entire planet okay and the left rule eight corresponds to the red line in the previous graph if we just continue without worrying about climate change temperature might change three to four for it there's a red portion there it might change more than five degrees Wow and that's a very big worry but we can change this was before this was done before the Paris agreement I need to put it up to date but the point is that if if that all the countries in the planet agree to do something we can certainly avoid the red zone okay and that's what the scientific community strengths is I think the most important message is not necessarily what's the most likely change but the fact that if we continue without measures we will reach temperatures that have not been reached in our planet by minn more than 50 million years when there was no civilization no people around that time and was an entirely different planet with crocodiles in the North Pole what that happening in tens of thousands of years with as a result of huge volcanic eruptions very unusual in the climate history of our planet 55 years ago this 55 million years ago sorry but this if it if we managed to do that in just a few decades what would be the consequences we would have portions of the planet uninhabitable because of the heat waves okay people cannot survive in places where the temperatures 50 55 degrees centigrade we would have massive loss of agriculture how do you feed the 9 billion people that are gonna live in the planet at that time you would have massive migrations all these extreme weather events some of them could go wild because you have many nonlinearities in the climate so the bottom line is that we label this as an extreme irresponsibility okay because science is well-established we're not talking about certain things we're talking about risks this is accused huge risk one in in in five of me one in ten is already totally unacceptable they just pointed two or three things in in one or two more minutes but here is one of them how did it come about that so many people do not believe in climate change there are of course some issues that have to do with the Republican Party I'll mention in a mineral first is it turns out Naomi Oreskes is a historian she was at this history department in San Diego we're not lecturing nowadays but she's now in Harvard and she published a book and there's now even a movie just documenting how some interest groups have to do with a couple of of fossil fuel industries they had a lot of resources it was not interested themselves but some of the people are financing some a couple of billionaires in that we have here in the United States they put a lot of money in in not just trying to affect the elections which they did very successfully in certain places they put a lot of money in the elections themselves but they put a lot of money with the news media trying to discredit climate science and that's not new that had happened it's the same company had that done that already with smoking you know that it's well-known that were for many years now that smoking and not everybody that smokes will suffer but it certainly can affect your health what these companies manage to put out in work were there were Jewish and so on and so forth so that governments did nothing about smoking until a decade later than science had already established that okay so that's one aspect but it turns out unfortunately you already mentioned that that the Republican Party just does not believe in this they sort of fail on this trap but it's no longer an excuse the scientist come is very well established and so it's no longer acceptable and we have this huge population we need to do something about it but let me just finish I'll give you one example what was a one in five probability me and with sometimes as you summarized it I fly a lot because I go from gave a number of conferences and so on and occasionally the pilot comes on board when you're already on the plane ready to take off and say we're sorry we have a technical problem we're gonna have to fix it wait might take a couple of hours but we just need to fix it but once a very adventurous pile of we have a technical problem I know we would have to spend several hours to fix it I know you are in a rush so don't worry what I'm gonna take off anyhow don't worry only one if I probabilities we won't make it to be who would like thank you for your attention yeah thank you very much indeed Mario hi I'm Adam Smith from noble media and it's my pleasure to moderate now a Q&A session with Mario after his lecture we have some time for questions and I do hope you'll take the chance to us some and there's a hand gone up already I love it great so please far away Mario if you're ready yes hey so yesterday one of the panelists said that there were numerous grand challenges that we need to face in order to survive as a species and climate change was special in that it managed to enter the consciousness of the general population and my question is what you think that the climate science community did that allowed it to make so much progress compared to potentially other branches that did not succeed as well then we make sure I understand the question is now if I time I change is special yes why is climate change special in public consciousness as opposed to all the other Grand Challenges it's the one that really has touched all public there have been a few efforts by the scientific community I've been part of a few of them I mentioned one which I didn't have time to explain here which is this one of planetary boundaries in which the what they are trying to talk about these problems that affect the entire planet of course you have a lot of local problems air pollution is is one of those poor in terms of issues affecting the entire planet they have been identified by this group and then many others have published around that and just established trying to measure what's wrong at what can we do and so on and so forth well it turns out that some of those worry sir are not yet sufficiently well understood and they remain to be further investigated and scientists recognize that they have to do with chemical pollution there are certain chemicals that are known to affect locally very harshly the environment but how is that going to spread out that's that's one issue other things like the phosphorus cycle yes we can do something about it were you using fertilizers far too much and it causes dead zones in the ocean so anyhow the point is that one of the most worrisome what I would say clearly the most worrisome one is climate change because we are already seeing enormous damage it's costing to the United States itself between two and three billion last year just for the Curie gains and another billion because of the forest fire so you can actually measure the damage but with a warning I'm a good friend of Nick Stern who's an economist that has been very active quantifying the damage and he had some economic measures early on that helped with the Copenhagen Accord and so on but one of his last reports would I very much agree with him is that the damage has been grossly underestimated and you cannot measure it in dollars only how do you how much does it cost to have 300,000 people perish in in a heatwave what's the cost well will be it's a moral issue so I want to stress perhaps this is my opportunity which I've known that science doesn't tell us what to do science only tell us what would happen but we have moral commitments we have values and we want to make sure that future generations have the same options that we have in this generation to have a reasonable standard of living and so on and so forth so that's why climate change is a huge issue because we're talking about enormous changes in society okay that we that can be well documented and if one issue where science is very well established were not making progress what do you expect of the other issues now fortunately air quality's just a good example of something that we can mix with climate change as is happening in China in Mexico as well as well so at the same time that you fix the air you can you fix emissions by not building more coal-fired power plants for example so that's one response put it the science is sort of tells us doesn't mean we should only worry about time a change that should be we have to worry about everything if whenever it's time thanks can you just wait for the microphone Thanks question I have is there there is indeed a great deal of consensus about the effect of climate change to me it doesn't seem that there is the same consensus about the solution there's a lot of people who believe that the use of renewable energies won't work I'm sure you're familiar with the paper that was put out by by the American climate scientists who said that one of them used a pejorative term about climate about renewable energy being believing in in the tooth fairy Jim Hansen said that and my point is how do we decide which is the right track when there are some people telling us renewable energies those correct paths the other ones saying no we've got to use alternative particularly nuclear energy yes well let me give you a couple of answers first that was an unusual paper it has been debated and I believe it by many industries let alone scientists it's many industries that are specialized in energy when fossil fuel and in the disagree with that because it's very clear you can see the the percentage of energy going from from these renewable sources increasing rapidly but most importantly that's what is not taking into account there is that the pop reactions they it's they are not that difficult technologically ok so if there is a sort of consensus that in years I have to be a chemical engineer myself or so but engineers will be able to solve that the problem is political okay so it is possible but nuclear energy certainly should be on the table that's much more debatable you see what happened in Germany but again much of my what I know about the energy perspective of it I get from a my team some part of this there's an MIT Energy Initiative and they have a board with many people from industry so I get not just the academic perspective but also industry's perspective ok and the view there is that I repeat that renewable energy is advancing very fast in spite of just a few papers ok most others don't agree but nuclear energy also is advancing a lot I know that it's worrisome what you do with waste but the amount of waste is very small so imprint that's a soluble problem it's a political problem where do you put it but in principle it's technologically it's something that you can deal with ok it's just the political is is complicated but it's the new the 4th generation nuclear the cheaper smaller nuclear reactors that are probably going to be relatively cheap and if indeed there are problems that are limited through their Bolinas to the conventional renewables that that will be able to help and there's one more point just to mention it which is we waste a lot of energy and we know that in some places the Scandinavian countries waste a lot less and they have a very acceptable standard of living so we can do a lot better without incandescent light bulbs with efficient air conditioning with much better insulation so these technologies are around the corner already and some are already implemented ok so that's yet another way in which the solution comes about but given the cost of not doing anything clearly overwhelms the cost of the solutions that are in the horizon already thank you that's a way I would put you okay oh they have the microphone hi I'm just wondering so a few people have proposed geoengineering methods such as injecting sulfate aerosols into the atmosphere to help cool the planet and counter the effects of climate change what are your views on those ideas okay two points first my views yes said I think it is all right and the scientific community should carry out the research but I also agree with the consensus that before we actually implement these measures we need to do the consult just like we do with with the United Nations with some international changes since you're gonna affect the entire planet it's not something that your scientist should decide the world being that you might have some unwanted side consequences okay what will will those be but yes you just have to keep learning and I just want to stress the point that that particular geoengineering solution was suggested that it's been advised by Paul Crutzen by my colleague with whom we share the Nobel Prize and I understand some of his points namely that you can put relatively cheaply sulfur particles in the stratosphere just like some volcanoes do and we know that the temperature drops when volcanoes explode vertically because most of them don't but if they do and inject in the stratosphere temperature drops if that's happened historically they drop one or two degrees just by one year and the point being is something goes terribly wrong you just stop that and it's not something that is going to last forever but the I guess the counterpoint is look it's not that difficult it was covered I guess the Lord it's connected to the previous question we have other solutions just reduce emissions and those we know that that's a natural way of doing that there are people suggesting yet other kinds of solutions which is to capture co2 in the atmosphere but that's very expensive at the moment maybe in the future there will be ways by the way there is also now a trend it's fusion for many years Fusion was 50 years in the future no matter when you were talking about always 15 years in the future but now there are some findings again knife mit has made a lot of progress here because they can have huge magnetic fields in a very small volume and the idea is that not next year but within a decade with my very well finally see fusion coming around that that would be imagine if you have a solution of that type without adverse consequences then you would not need geoengineering but by all means let's keep exploring that just your if it becomes really necessary thank you question here please so I've encountered unfortunately individuals who would think that Oh a few changes in temperature or Celsius when it makes such a difference how do you approach responding to someone to get them to grasp the importance of even a few temperature even a few degrees well dude show them some of the consequences that were already having it's not just a few degrees that matter and in fact we acknowledge that in some places on the planet you you will have some benefits but what we have seen just in the last few years is very clear examples of negative consequences and you can cite many examples among them that glaciers in the mountains are melting okay now in principle you won't be able to to do tourism over there and look at the nice pieces of ice off so what no no this matters because that's a very important water source for agriculture in some places or what happens is if if the rainy season in in in in India changes completely and they won't be able to do agriculture the way they are doing so it's a change part of the explanation is that society civilization and so on has grown in the Holocene with very few climatic changes okay and if we have changes that are happening very fast it's a change itself that gives us travel if the temperature had been a few degrees warmer for tens of thousands of years per civilization would have probably evolved in in a different way but the change and the non be unknown nonlinearities that if you are scientist you probably know that you suddenly reach a threshold and suddenly things change not smoothly but suddenly okay the the main difficulty here because of the complexity of the climate is that it's very hard to predict but these these so-called surprises okay so that you would have just to show them by example and that's one disadvantage of condensing the conversation just in the two degrees or in the temperature change it's just one way to illustrate what I would emphasize it's an oversimplification to talk just about this surface temperature change that just one way to summarize issues but it's not the main worry thank you please yeah thank you so much for the great lecture one thread that I hear that is common to yesterday's discussion and your lecture today is that our greatest challenges are not scientific and technological they are political and cultural right would you agree that we need more Grand Challenge initiatives that address politics and culture yes very much so and let me give you two so ways in which we can do that one way is extremely important unfortunately not very fast but nevertheless they're really important and that's a change in a decay because we have now new waste to educate starting with with elementary school how children learn science and there are new ways to do that in which they learn it very much faster much more efficiently and it's they not only it doesn't work much better it's much more entertaining okay so you get the children to really enjoy doing science but other subjects as well how because it's the so called active or interactive learning and that happens also in college it happens at all levels but in college instead of just listening to somebody you actually discuss you form groups and and so on it's a it's a long story board that's happening already at MIT and hardware there are some of these courses and the most important thing is that in this fashion you can also talk about values okay children learn to appreciate nature then they go back to their homes and they are the ones telling their parents to not waste energy for example okay because they love nature if they are properly educated and so what one big expectation is that the new generation the younger generation when they get what they need to get eventually decision makers and so on they will be much more responsible because unimportant value is let's all work together and make sure that we do things that not just for our own personal benefit but what for society at large okay so that's one way but that's I I understand that will take some time but it's no longer waiting three or four generations but the other way is we're making some progress when we talk to politicians and we sit down with them and so on with many of them things work we were talking about people in government with we have Republicans but what is amazing is Republicans from past administrations I have many good friends there very eager to change they just cannot convince many of their fellow Republicans that are currently in Congress okay what they are changing already okay things are beginning to be so clear the past changing it's not changing at the level of the presidency yet okay but hopefully that's temporary for the Republican Party as you know is changing so we think we can do it because it makes so much sense and because we can actually put it very clearly on the table what are the reasons that you don't want to lose we know the Tea Party initially the reason was we don't want government interaction with anything and so anything such as climate change we should just discredit but that's exaggerated obviously the government needs to help with some measures such as at the example I always put on the table which is obvious now is the government is the one responsible for removing lead in gasoline and we say no the government shouldn't touch what the private industry soon how many children would have died without that type of government action and now air quality in many developing countries many people would die if the government just says no I let I will let the private sector do what they need to do no it's very clear that government should act what it should do it appropriately getting the sectors that are affected involved in the decisions and whatnot I hope I'm an optimist and I think well nothing less than the Paris Accord okay well I'm biased because I was in pikas which is the President's Council of Advisors in science and technology so I work with President Obama I heard 20 of us and we a few of us there were time a change sort of scientists and we talked to him many times and defined essentially the Paris agreement what do I mean it was defined in such a way that the United States could pass it what did that mean that means up that means meant that US Congress had nothing to do with the Paris agreement because they would not have agreed with it to me but that's changing now we hope thank you another question please so a lot of experts agree that agriculture is one of the largest global emitters of greenhouse gases and not only in that respect but also a huge waste of water the use of pesticides and fertilizers some of these experts agree that a change to permaculture might be a solution to fixing that part of the greenhouse gas emissions issue so to what extent do you think that collaboration between agriculture scientists and climate scientists as well as other changes for example turning to indigenous cultures for knowledge on how nature works without necessarily the rigor of scientific investigation but just inherent knowledge of how these systems work well I think you can you can mix it you can if you have some ideas about some changes in agriculture you can do scientific tests and that that has happened so there's it need not be incompatible but that's a recognised aspect of climate change it's not necessarily the the largest or the most important because it's again burning fossil fuels both agriculture practices had been part of this whole idea and in fact that peak as I was just talking about this group with with President Obama we have if not one and maybe two reports on agriculture who are we met with experts some actually from this University that were very much experts on these issues and yes there are problems excess use of fertilizers okay that effect the nitrogen cycle and so on so what that should be improved but it's even more important in developing countries where they're just wasting resources okay so there is a lot that can be done with agriculture to improve the practices and again it's a huge challenge not just because of climate change for the you have to feed a growing population but fortunately I think there are there's good science in that field which is far from my own field but as I understand there is progress but there again the politics is remains to be worked out and just give you one example which is in Mexico for we deal with with science policy and one of the things we're trying to change we have not succeeded yet is there is an incentive in agriculture where the government simply gives away water and electricity and that's not very wise because then people in business and so they don't care they can waste water electricity government pays for it why should we care so we are suggesting to change the subsidy not to remove it but to give them the resources in in cash inclusion in some other way but so that they don't just waste the water and the energy and so there are many examples like this in the here and in the developing world that need to be changed with the help of science but again we're talking a little bit about the politics the science and the technology thank you a quick question from this side first please Naomi Klein in this changes everything says that it's capitalism versus the climate and since emissions have really increased under this deregulated capitalism and a lot of industry um is just not regulated or punished for its over admitting do you think that we can really make progress without changing like the economic system that's a good question and I think let me be very optimistic I think we can because capitalism is the only form of guess of government that we know works has many problems ok but we know that for example the Soviet Union didn't work out before so and and Venezuela is not working at all and so on so other systems have big promising what capital is if it's properly managed if you have the population well-informed and the politicians responding to that we believe it can be done and we have many examples of industries here in the United States that are socially responsible and acknowledged you can make money and still you can protect the environment and you can make sure that you're not doing damage to future generations it's possible but we need to work together ok that's what we should do having spent 48 hours standing next to you I think optimism is the word that best defines you most optimistic laureate I've ever met it's fantastic please so a big thing I've picked up on here is that there are a lot of political issues back behind this that the science is there but the politics isn't quite there we need to be optimistic about it but how do we get governments go along with climate change how do we get people to rally behind it like you were able to rally behind the ban of CFCs well we almost did it we just have I think a temporal problem now here in the States but with the with a mantra protocol I was there we were able to make it it worked it happened all the countries in the world accepted Margaret Thatcher who by the way she was a pharmaceutical chemist okay so she was a scientist but she very much initially was a little post weak until she understood everything and then with Ronald Reagan they did it they were very conservative governments at that time let's talk about climate change in Paris because that was still with President Obama poor I was able with shake hands with lots of heads of states they all took a photograph 150 I don't know how many of them they all agreed so it can be done okay one trick is to go to high levels but unfortunately there are exceptions we have to be optimistic and we have to keep working you can argue and say Oh society will evolve civilization will advance no matter what let's just wait no I would say that's alright but it won't happen by itself we need to be there we need to work we need to work all together and I think we can do it that's my optimism thank you so much I think I think we should stop there and summarize your whole approaches keep working it can be done that's right and that seems an appropriate place to stop so I'd like to thank you very much indeed Maria for everything in place and [Applause] [Music]

Channel: Nobel Prize

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Id: U_bXzc6hfGM

Length: 78min 50sec (4730 seconds)

Published: Thu Jun 21 2018