 Our session is called Energy and Climate Change, and I just want to remind everyone that while these two issues are closely related, climate change is due to more than energy. And in particular, roughly speaking, one quarter of greenhouse gases comes from agriculture and changes in land use. And so when we think about climate change, we should not only think about energy. We have to think about energy is important, but we have to think about other sources of greenhouse gas emissions as well. We all heard last night, Laurent Fabius talk to us about the urgency of dealing with climate change according to him, and he's been involved in an intimate way now for at least 10 years. He reported on the latest IPCC report, which I have not read. I've only learned about it from a few newspaper articles and what he said last night. But two things surprised me about what I have not read, but have heard about. One is its specificity. I followed the science of climate change for at least two decades and as an interested observer, not as a scientist, and there's still huge uncertainties, including the sensitive sensitivity, it's called, of the climate itself to greenhouse gas concentrations in the climate. They have not changed in 25 years, one and a half degrees centigrade to four and a half degrees centigrade for a doubling of CO2 from roughly 1800. So we've invested tens of billions of dollars in research on climate change. We know much more than we did 20 years ago, and one of the things we know is how complicated the earth's atmosphere and oceans are, so that in spite of all of this greater research and we're much better informed on individual pieces, we still do not have an accurate overview of climate change and its relation to greenhouse gas emissions. So I was given that background. I was surprised at the specificity that was reported, at least, again, I haven't read the report, but I've reported in the newspapers and in Fabius's speech last night. And in order to get that specificity, they had to make a lot of assumptions about things that we actually don't know about. They may be completely right in those assumptions. I don't have a judgment on it, but they may be also badly wrong. And so we should not take that as firm knowledge about the climate, even from the accomplished scientists. The other thing that surprised me, this is again from newspaper articles in Fabius's speech, is the degree of urgency, which was conveyed, apparently, to the readers of the report, and maybe by the report itself, and statements about 2030. And I will just say flatly, as a practicing economist for half a century, that that will not happen by 2030. So we should get it out of our heads that we're not going to turn society over around the world over the issue of climate change. It's just not going to happen. Now what might happen is that we overshoot, and then technological improvements permit us to go back down to one and a half. I don't rule that out. But the notion of stabilizing the average temperature increase at one and a half degrees centigrade by 2030 is just out of the question in my view. And so we need to think about much more actively, if the scientists are right in what they say, much more actively about adaptation along many, many different fronts, not just building seawalls, but with biodiversity and so forth. The human agency can adapt the, of all of the species. The most adaptable are probably human beings, some ants and some bacteria. But the human beings have an enormous capacity for adaptation to change, particularly if there's notice about when the change is coming as we have increasingly. So I think it's, I guess I would say, bad politics to urge strongly that we do something that's going to be impossible. That sounds like Mr. Trump, he actually has some things that might not climate change, but other things which I think are possible. Now my view on the trajectory, talking just about the energy side, I know that a number of environmentalists at least in the United States, and I gather in Europe also deeply regret the shale gas revolution on the grounds that it's another fossil fuel and it generates greenhouse gases. And of course they are correct in their factual statement, but per unit of useful energy, natural gas in producing electricity produces about half the greenhouse gases as coal does. So the, my trajectory for the, not the next decade, because I think it's impossible, but say for the next three decades is natural gas as the bridging incremental fuel and solar as the ultimate source of energy supplemented by wind and other things, geothermal, but the main source will be solar. And if we've heard from the previous presentations, the cost of solar energy has come down dramatically just within the last decade. And so basically in the short run, the thing we need to do is above all prevent the building of new coal-fired power plants, which is strongly against climate change and of course heavily polluting. And then there's the question of what we do with existing power plants, those that still have economic value. And that's an issue certainly for private firms as in the United States and some other countries, but even for state ownership of coal-fired power plants. And that's an important budgetary decision. Do the coal-fired power plants, which have very low operating costs, once the capital costs have been incurred and they last for 40 or 50 years, are they going to be taken out of production? And can we have an international agreement on that? Probably not. Can we have an international understanding that it would be desirable, probably feasible, leaving aside Mr. Trump for the moment? And then it would be up to individual countries whether the extent to which they accelerate the shutting down of existing coal-fired power plants. But above all, we have to stop building new ones. And we have not built any coal-fired, coal is still very important in the United States. But we have not built any new plants for the last 35 years. All the incremental power has been achieved by natural gas, which has much higher operating costs, but much lower capital costs to build. And we've expanded some existing coal-fired plants, but we've built no new ones, and all, as I say, all of the incremental, apart from a modest amount of solar and wind and those renewables. And then if we're bridging a period with natural gas to solar, the issue comes up, which has been emphasized by our previous speaker, electricity storage. I'm glad she did not use the word batteries because batteries are one form of electricity storage, chemical storage, basically. But there are other forms of electric storage. Batteries, what we could call batteries in general, are perhaps necessary for electric vehicles, which move around. But they're not necessary for stationary sources of power. And the true traditional ways of storing electricity, think of wind and solar when the wind's not blowing and the sun's not shining, are pumping water. And of course that only works if you have a lot of water, which you can pump. And flywheels. Flywheels have been understood for many, many years. They're relatively cheap to build. To build a really first class one requires special materials. But to build ordinary ones are cheap to build. And you can imagine under any wind turbine or a collection of wind turbines, five wheels around which store the electricity and which can be drawn on when the wind is not blowing for mobile things like cars and trucks and airplanes. Of course batteries are much more important in the traditional sense. And probably mostly chemical unless we go to hydrogen as a fuel. I have long favored under the heading of climate change, nuclear power. So I'm not a conventional environmentalist in that sense. But as we've seen today, nuclear power is now outclassed in terms of cost. Unless we get new smaller modular nuclear power plants, which have been designed down the river from me at MIT and in other places. We have not seen them yet in commercial use. And so they remain to be tested. I saw recently a press report on fusion saying that practical fusion, commercial fusion was five years away. I'm old enough to know that it's been said that fusion was just within a two decades since the mid-1950s. And I simply don't believe it. And I'm not willing to put more money in it as a taxpayer, but some people are apparently. So we're still working on fusing. But I don't see fusion as a practical operation in this. And I guess in talking about timing, I'm persuaded of the tremendous inertia in human affairs, even in a rapidly growing economy like China and now India and more slowly growing in Europe and the United States. We have a lot of legacy, capital stock, very large in the United States and Europe, but even in China, we heard in an interview today that there are now nine million cars in the world from Goshen. Nine million cars. In the United States, the average car lasts eight years. That's the average. I drove a car once for 14 years from the time it was made until the time I sold it, actually, didn't junk it, I sold it. So think about converting those nine million cars, all internal combustion engines into climate change friendly vehicles. If we were to stop producing internal combustion engines this year and from January on produced only electric cars, only electric cars, it would take nearly two decades to replace the outstanding stock, of course, and there are also trucks and other vehicles. And then I want to remind everyone, I'm sure everyone knows here, you cannot just look at the vehicles that are electric. You have to look behind it to how the electricity was generated. And we still generate most of our electricity with fossil fuels. And so you have to look at the entire cycle and not just the fact that the car is electric. Let me say a word about Mr. Trump and his withdrawal from the Paris Agreement. It happened by coincidence. He announced his attention to withdraw in June of 2017. And as you probably know, it actually takes three years to formally withdraw. So he announced his intention to withdraw. Two weeks later, we had an annual conference of mayors. It's an annual conference. Two weeks later, representing 1400 cities, all of the largest cities in the United States, and the Conference of Mayors, Republicans and Democrats, voted overwhelmingly that they were not giving up on addressing climate change. Now it has to be said that many cities do not have a climate change policy. But surprisingly, perhaps many US cities, including mine, Cambridge, Massachusetts, do have a climate policy. And the Conference of Mayors in direct reaction to Trump's announcement have announced that they were going to carry on. And of course, we know some states, California up front, but that includes Massachusetts and other US states, are going to carry on with climate change. And the time dimension of this issue, problem, challenge, is such that Trump will come and go before it's been solved seriously. And so I do not, Trump can do a lot of damage as president, but it's not mainly in this area. Things are going to carry on. They're going to be driven mainly by market phenomenon. Well, we've talked about the changing cost structure for solar and wind and nuclear and coal. And so that's not high on my priority list of things that the damage that Trump can actually do. Well, I have lots more I can say, but that's probably time to stop and we can talk about other things in Congress. Thank you very much, Dr. Cooper. As you say, this IPCC's 1.5 degree C special report was just released. And they are very kind of ambitious or really surprisingly tough and very specificity there. And to make net zero emission by 2050 is necessary. And compared to the two degrees Celsius scenario, we need three times or four times more investment needed. And as you say, if overshooting happens, definitely the carbon capture and storage or usage will be the key technology to achieve net zero emission by that time. So carbon storage and capture is really technologies there. But without carbon price or carbon tax or some kind of penalty on carbon, this is very difficult. So the United States in some companies has carbon pricing and reducing the carbon contents. But this carbon capture technology, it's only possible in Saudi Arabia or this oil producing country as an enhanced recovery. But just burning coal and take out carbon dioxide. And put it underground is probably almost impossible. So now the other technology, direct carbon capture from the air is also discussed. So the things is, but this is another very high cost. Other things is, yes, battery of the electric vehicle as a system. If there's a millions of electric vehicles on the market or on the street, they could be connected. And they can provide the gigawatts of storage as a system. So that is one of the Chinese strategy or some of the EV companies are thinking about. It's a digitalization and connectivity solve part of this storage program. Fusion interesting, and some of the fusion company in the United States are really ambitious and some money venture capitalist put in. I hope one of them may work, but we'll see. That's a part of my comment.