Winter 2017 Bulletin

Global Warming: Current Science, Future Policy

On November 15, 2016, the Academy’s San Diego Program Committee hosted a Stated Meeting at the Sanford Consortium in La Jolla, California. Veerabhadran Ramanathan (Distinguished Professor of Climate Sciences, Scripps Institution of Oceanography, University of California, San Diego) and David G. Victor (Director of the Laboratory on International Law and Regulation, and Professor in the School of Global Policy and Strategy, University of California, San Diego) discussed the state of the scientific understanding of climate change and the implications of this knowledge for the development of future policy. Gordon N. Gill (Chair of the San Diego Program Committee; Professor of Medicine and of Cellular and Molecular Medicine Emeritus, University of California, San Diego School of Medicine) moderated the discussion. The program served as the Academy’s 2046th Stated Meeting. The following is an edited version of the presentations.

Veerabhadran Ramanathan
Veerabhadran Ramanathan is Distinguished Professor of Climate Sciences at the Scripps Institution of Oceanography at the University of California, San Diego. He was elected a Fellow of the American Academy of Arts and Sciences in 1995.

I just returned from a UN organized climate summit (COP-22) in Marrakesh, attended by many of the world’s leaders. I participated as an appointed member of Pope Francis’ Holy See delegation. In addition, I was cochair of an international working group that came up with a roadmap on how to keep global temperatures from rising more than two degrees. Our report was released for comments at Marrakech, and it was in support of the UN Paris Agreement of 2015, which set out a global plan to avoid dangerous climate change by limiting global warming to well below 2°C. The warming magnitude mentioned in this document is in reference to temperatures of the pre-industrial era (before 1800).

Let me begin with some background about climate change by using a familiar example. Most of our cars burn gas. What comes out of the tailpipe is basically carbon dioxide. Fuel is a hydrocarbon, so the carbon in the fuel combines with oxygen and becomes carbon dioxide. This is probably one of the deadliest gases as far as the environment is concerned. Once that CO2 is released, about 50 percent of it stays in the atmosphere for roughly a hundred years, and about 20 percent stays in the atmosphere for thousands of years. I’m confident that whatever James Watt’s first steam engine emitted is still there. It doesn’t go away, and that’s the problem.

So from James Watt’s time to 2010, we have emitted two trillions tons of carbon dioxide. Our best understanding is that each trillion ton warms the planet by roughly three-quarters of a degree. There is a threefold uncertainty in any number I give linking emissions to global warming. At the current rate of emission, we are putting out about 40 billion tons of carbon dioxide every year. If the current growth of emissions continues unchecked, by 2035, we will have emitted the third trillion ton of carbon dioxide, and that’s enough to warm the planet by more than two degrees, particularly since we are emitting other greenhouse gases. Because of the inertia of the oceans, it takes some time for the full effect. By 2030, I predict that the planet will warm by a degree and a half. It has already warmed by one degree, and by the time you emit the third trillion the planet will be on its way to warm beyond two degrees. So the steep climate changes we are talking about are not a hundred years or even fifty years from now, but closer to fifteen to thirty years. For a past example of the planet warmer by a degree and a half, you have to go back to the Eemian Period of 130,000 years ago, and the warmth then was enough to raise the sea level by about 4 to 6 meters (approximately 20 feet). It likely took centuries to millennia for the sea level to rise by that amount.

So what does the warming mean for California? Every degree rise in the soil temperature – I’m using the Celsius scale – increases evaporation of moisture by somewhere between 7 to 15 percent. The soil eventually becomes dry if the increase in evaporation is not compensated by an increase in rainfall. And when the soil dries the trees dry and become combustible. These facts are well known. At this stage, you might logically ask, “How can you make a prediction fifteen to thirty years in advance?” Let me explain by showing you my track record. In 1980 – that was thirty-six years ago – I teamed up with a meteorologist, and we studied natural variability. We predicted that the carbon dioxide greenhouse effect would show up by the year 2000. As some of you may know, this prediction was verified in 2001, when about two thousand scientists concluded that they were seeing a discernible warming in the temperature record, which was good news for climate science but not good news for the planet. But as you know, science is judged by the predictions it makes.

So how does the carbon dioxide warm the planet? Since the gas stays in the atmosphere for centuries, it has covered the entire planet like a blanket. One of the first persons to document this was David Keeling, whose recording of carbon dioxide at the Mauna Loa Observatory first alerted the world to the buildup of carbon dioxide in the atmosphere.

We see CO2 everywhere, and we take measurements in the Arctic and Antarctic, Pacific Ocean and Indian Ocean. There’s no place on the planet that is not polluted with carbon dioxide. As I said previously, it covers the planet like a blanket. And just like a blanket that warms you by trapping body heat, this is exactly how CO2 works: it traps the infrared heat emitted by the surface and the atmosphere. But how do we know how much heat it traps? The answer basically follows from the quantum mechanics of the CO2 molecule. The carbon atom is in the center, surrounded by two oxygen atoms, which vibrate back and forth around the carbon atom. This vibration is what heats the planet. Arrhenius, the famous Swedish Nobel laureate, made the first prediction 110 years ago that a warmer planet would be more humid. The increase in humidity would cause the rainfall to be more intense with many more floods. All of this was predicted.

Until 1975, we thought carbon dioxide was the only manmade greenhouse gas. I was not studying atmospheric science then. I was not a meteorologist. I was working on the greenhouse effect on Venus. At the time, I was researching chlorofluorocarbons (CFCs), which were used as a refrigerant, and my discovery somewhat shocked the community. I found that one ton of CFCs has the same warming effect as more than 10,000 tons of CO2. The previous year, two chemists – Mario Molina and Sherwood Rowland, both at UC Irvine – published an article that claimed that CFCs were chemically damaging the ozone layer. Because of the effect on the ozone layer, the Montreal Protocol, which was really ratified during the Reagan administration, banned CFCs. However, the Montreal Protocol did not recognize my work on the global warming potential of CFCs. As a result, CFCs were replaced by hydroflurocarbons (HFCs), which are a thousand to four thousand times more potent than CO2. But finally, forty-one years later, on October 16, 2016, the Kigali Amendment to the Montreal Protocol banned HFCs because of their greenhouse effect – and this was the first ratified, legally enforceable treaty that recognized the greenhouse effect of non-CO2 gases. I had to wait for forty-one years for my discovery of the super warming effect of halocarbons (CFCs and HFCs) to be recognized.

The discovery of the greenhouse effect of halocarbons opened a Pandora’s box, and numerous other manmade non-CO2 greenhouse pollutants were discovered. Among them were the super pollutants (that is, much more potent than CO2): Methane; Ozone, HFCs, and black carbon. Black carbon is an aerosol (particle) and it warms the planet by trapping sunlight (not infrared radiation as in the case of greenhouse gases). These four super pollutants are called short-lived-climate pollutants (SLCPs) since their lifetimes in the air are very short (from a week to a decade) compared with that of CO2.

Many people think we can see an immediate effect if we decrease CO2 emissions, but because of its long lifetime in the atmosphere, it will take thirty or forty years. How will the president of the United States explain to his citizens that they have spent a lot of money to cut CO2 emissions, and they will not see anything for thirty or forty years? Well, with the short-lived pollutants (SLCPs), you see the effect immediately. Here California can serve as a model, a type of living laboratory. If California’s pathway for reducing carbon dioxide and the short-lived pollutants is followed by the rest of the world, we can keep the warming under safe levels. California is going to ban the black carbon emissions from diesel vehicles. And now the United Nations – in fact, then Secretary of State Hillary Clinton began this – has started a coalition to cut the short-lived pollutants.

Let me come back to the report we released at Marrakesh. My cochairs for this report are Mario Molina (a Nobel laureate in chemistry) and Durwood Zaelke (an environmental lawyer), with a team of thirty that included David Victor, diplomats, people from the military in the United States and India, and scientists from China and all of the EU countries. We followed a strategy with four building blocks. The first one is the Paris Agreement, which David will talk about shortly. The second building block is the sister agreements, and I mentioned an example previously, which is the Kigali Amendment to the Montreal Protocol. Other examples include two other major agreements to reduce emission from aircrafts on ships. The third one is an effort called Under2 MOU (Subnational Global Climate Leadership Memorandum of Understanding). California Governor Jerry Brown spearheaded the effort to get 156 jurisdictions to sign onto the agreement, including ten cities from China alone. The hope is that even if our nation doesn’t step up, the Under2 MOU will catch on. The entire West Coast is part of this, and Canada too, so we are optimistic.

Basically there are two levers: carbon dioxide and SLCPs. Even if we decrease CO2 emissions beginning today, the CO2 concentrations in the air will keep increasing until we reach zero emissions. We need, therefore, to bring in another lever that will provide some quick relief from the warming. That lever is the SLCPs. However, if we delay taking action for another ten years, we will have to invoke a third lever to remove a trillion tons of CO2 that is already up in the air; and the current cost of that can be as high as $100 a ton. Society will have a huge price to pay if we don’t take action in the next four or five years.

In my work with the Pontifical Academy of Sciences, I have been calling for an alliance between science, religion, and policy. I have been in the Pontifical Academy for ten years; Pope Saint John Paul elected me. It is a small academy with eighty members, and about 30 percent are Nobel laureates in biology, physics, and chemistry. So you might ask, what business does religion have in science? In fact, in the case of the environment, science and religion seem to want the same thing. Science calls it protecting nature; religion calls it protecting creation. So there is that commonality, and we are trying to take advantage of that.

Let me conclude with a final point. I am working closely with all ten campuses of the UC system, and with our president, Janet Napolitano. Starting this spring, we will be offering an undergraduate course on climate solutions. Our goal is to branch out to other four-year colleges – we have already started conversations with CSU – and two-year colleges, and then take it nationwide. We want to train a million climate warriors armed with knowledge of solutions. And then we want to reach the K-12 level. I have teamed up with the dean of education at UCLA, Marcelo Suárez-Orozco, and we are planning an education summit in the fall. So, I’m optimistic together we can solve this problem in time.

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David G. Victor
David G. Victor is Professor in the School of Global Policy and Strategy at the University of California, San Diego, and Director of the Laboratory on International Law and Regulation.

I’ve been asked to talk about policy around climate, and I’m going to focus on three things. First is the evolution of international policy strategies on climate change. Fundamentally this is an international issue – not just because most of the pollution that causes climate change mixes in the global atmosphere, but also because cutting emissions probably will be expensive and thus affect the competitiveness of national economies. Nations – as well as cities and many other units – have shown that they are willing to do a lot. But they probably won’t get anywhere close to zero emissions – which is more or less what’s required to stop warming – unless countries have confidence that other countries with which they are competing economically in the global economy are also doing something.

Globalization for the most part is going to make this an easier problem to address because it has radically accelerated the speed with which technologies move around the global economy, and that means that new ideas, such as new low-emission technologies, are going to get adopted quickly in all corners of the world. When I travel, I like to visit power plants and refineries. I look at who built the plant and I talk to managers about the factors that affect the operation of their facilities. And it really struck me that twenty years ago or so when I started visiting power plants in all corners of the globe, what you would see on an Indian power plant was an Indian nameplate, and you would see on a Chinese power plant a Chinese nameplate, and the same in an American power plant, and on and on. Today, when you visit the best plants or the best industrial facilities almost anywhere in the world, you see the best nameplates and best technologies adopted very quickly. So globalization for the most part is going to make the problem easier to solve. But one of the ways in which it’s going to make it much harder is the extent to which countries are attentive economically to the effect of regulation on economic competitiveness, growth, and jobs. Certainly we saw some of that in the last election and it makes them very nervous about whether other countries are doing their part, so I want to talk about how you organize international cooperation in this area.

From the early 1990s until just a few years ago, the answer was that we didn’t do it very well. We had a series of international agreements that had essentially no impact on the emissions that are actually causing the climate change problem. We had the Kyoto Protocol, which the United States didn’t join, but when you actually look closely at whether the Kyoto Protocol had an impact on emissions, the answer was essentially no. The Paris Agreement, the framework set up almost exactly a year ago in Paris, has a very different and new approach and one that is poised to be dramatically more effective than the earlier efforts. This is true for a lot of reasons, but I think the central reason is that it’s much more flexible and decentralized. It relies on countries making their own pledges and, in the months leading to Paris, 185 countries made those pledges. What’s really interesting is that when you look closely at the pledges, every country has a different strategy, because every country has a different set of national priorities and capabilities. They’re thinking about how climate change is going to map onto what they’re trying to do at home. The Chinese strategy and, now, increasingly the Indian strategy are very much focused on how do they control local air pollution and a variety of other things that are urgently important but also happen to reduce emissions of the pollutants that cause warming. Here in the United States our strategy is different, and the European strategy is different yet again. Brazil’s strategy is focused on the area where Brazil has had the highest emissions, which is around deforestation. They’ve made extraordinary progress over the last decade or so in part because outside funders, Norway and others, have helped them find and fund new solutions.

What’s smart about the Paris approach is it decentralizes this process of countries setting their own commitments, making pledges, and then periodically reviewing those commitments and those pledges. It’s a very different approach than what we see in many other areas of international environmental cooperation, which are much more integrated. The Montreal Protocol that Ram mentioned is a tightly integrated treaty system that initially focused on one or two classes of pollutants, and then, as diplomats and firms gained confidence in how to regulate those pollutants they added still more pollutants to that same, integrated core. What makes climate so difficult from a policy point of view is that the topic is intrinsically highly decentralized, and it’s impossible to imagine how you could create a single integrated treaty system. Instead, what diplomats have learned the hard way over the last twenty-five years is that they needed to decentralize these activities and give countries more flexibility to figure out what’s going to work in their own contexts.

I’m extremely optimistic that this is going to work. I wrote a book, Global Warming Gridlock, that explains why most of the things we’ve tried to implement with climate change haven’t worked very well, because the problem is, structurally, a very difficult one to address. One of the core arguments in that book is that the diplomatic effort would continue to fail unless it decentralized the process more and relied more on national commitments. That model is now being followed with the Paris Agreement.

The second of the three things I want to talk about is our expectations. It’s really important when we think about climate policy to keep our expectations grounded in reality of how quickly this process can unfold. And I want to concentrate briefly on two areas where I’m most concerned. One of them is the goals. This is a disagreement that Ram and I have been having since Charlie Kennel at Scripps and I wrote a paper in Nature more than two years ago that said that the goal of stopping warming at two degrees was impossible to achieve. When I look at this from the point of view of a political scientist who studies technology and regulation, I don’t see how you get to two degrees. It’s not that I can’t imagine all the levers being pulled – I was a coauthor on the paper with the three levers that Ram described. But what I have a hard time seeing is how you pull the levers fast enough and hard enough in order to really stop warming at two degrees. I think we need some sobriety around how quickly we can actually stop this warming both from a policy point of view and in terms of how the energy system changes, because historically the energy system needs about three or four decades if not longer to completely turn over the technological base.

The problem, of course, is that the time horizons needed for change in the energy system are a lot longer and move more slowly than the rate of change that many climate scientists say will be needed. That’s the brutal political reality of this problem.

If there’s any simple prediction that a political scientist can make studying the climate change issue, it is that society as a whole will under-mitigate emissions and will therefore be forced to over-adapt. That is, compared with a society in which a benevolent, all-knowing person is in charge, the real society in which we live will not make adequate investments in a timely enough way to control emissions. This will therefore force us and our successor generations to adapt to the effects of climate change that will be greater than what would be socially optimal. That brutal political truth reflects that the problems of controlling emissions and adaptation to climate impacts have a very different political structure. Controlling emissions require that countries cooperate on a difficult problem over many decades, implementing expensive policies in order to make a difference. The benefits of this action are far into the future; the costs are diffused and visible today. By contrast, if societies wait recklessly for climate impacts to be apparent then the benefits of action are more visible and accrue locally. If you build a sea wall, the jobs accrue locally. The concrete is bought from local firms. And so, as a general rule, I think we’re going to see a global strategy that will under-mitigate and over-adapt.

The other area where I think we need to keep the right expectations is the balance between what’s going to be done globally in institutions like the Paris Process, which has an official meeting underway in Marrakesh right now, and what’s going to be done in other groups. Even as the wheels of global climate diplomacy grid on, there are more focused groups of countries working on specific pollutants – as seen in recent weeks with the Kigali Agreement to the Montreal Protocol. I spent a lot of time in Norway, working with the Norwegian government to develop a strategy to regulate soot in the Arctic region. In the Arctic, all you need are ten or eleven countries, maybe not even that, working hard on soot pollution to have an enormous impact on the pollution that ends up in the Arctic. So what you see right now is a shift between talking globally and being friendly to everybody globally. Most of the real progress in managing the climate problem, however, is occurring in places that are focused on specific pollutants or in very small groups of countries where the cost of organizing that group and implementing policies is much lower than the cost of working in a group of 185 countries. The Paris Process offers an umbrella under which many more focused efforts can flourish.

The last thing I want to talk briefly about is the unavoidable topic of Trump. The man has become like a national Rorschach test for your view of government. Some people see in him a successful businessman who is on television and who is out there getting things done – he is going to fix the problems that they see in society and tell it like it is. Other people envision a horror show for all manner of public policies, protection of minority rights, and so on. And that Rorschach test in some sense is playing out right now with climate. The last six days since his surprising victory have been extraordinary. I’ve spoken with thirty or forty reporters from around the world – the shock here in the United States has been palpable, but that shock is reverberating around the world.

How do we make sense of what the Trump administration will do on climate policy? I think the areas of greatest harm of the Trump administration are going to be in the places where the president has the most immediate leverage, which is not domestic policy. Almost all of the significant domestic policies that affect our emissions are beyond easy control of a president. Most of these national policies are written into statute or in finalized administrative rules that are difficult to reverse. But the place where the president can have a big impact – what’s already being felt in Marrakesh – is on international policy, where stopping the flow of international funds is going to have an immediate effect on U.S. credibility. The Paris Agreement, we have to remember, is not a single event but a process in which they settled on what was agreeable and then left all the details, like how this pledge and review process are going to work, for later. It requires countries to step up and say, “Here’s how we’re going to do it.” The United States was in a position to do that along with some other countries, and I think we’re probably not going to play that role now.

To me, one of the most interesting things is that I suspect the Chinese will fill the vacuum. The government of China has become much more comfortable talking openly and internationally about its climate policy and about its efforts to control emissions. The architecture of the Paris Agreement in many respects is one created by the United States and China together when the leadership of our two countries jointly announced our pledges to cut emissions about a year before the Paris Agreement came into effect. With the Americans off the scene, I think you’re going to see the Chinese play a much bigger role, and this could actually end up being a kind of watershed event for how the Chinese see their engagement with global institutions.

I want to close with a couple of observations. Everybody has been talking about the negative impacts of the Trump administration on climate policy, and I do think we need to worry about the discourse around climate change policy. When polarizing figures are in power the entire debate becomes highly polarized – are we in favor of climate policy or opposed to climate policy – whereas the most serious debates that we need to have, especially inside the university, are about how do you design the policy? What really works? Do these efforts to try and stop pipelines have any impact on emissions? The short answer is no. They’re completely symbolic activities.

So I think climate policy is going to take a hit in the Trump administration. There’s no question about it. But we have to remember that there’s a tremendous amount of inertia in the system. There are other countries willing and able to step up and replace U.S. leadership on this issue – even China, which traditionally has not really been a leader in the sustenance of international institutions. We have to remember that technological change continues, and to me, as someone who studies energy and energy markets, it’s just extraordinary how much is changing in the direction of new technologies that have reduced costs for controlling emissions. I think this is going to make the problem easier to solve over time. But it won’t automatically make it possible to stop climate change quickly – the world is in for big changes.

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© 2017 by Veerabhadran Ramanathan and David G. Victor, respectively

To view or listen to the presentations, visit