Climate Change - Perspectives from a Scientist and a Scholar -- An Interview with Professor Daniel Schrag

June 8, 2021

By Tom Conforti

Daniel Schrag is the Sturgis Hooper Professor of Geology, Professor of Environmental Science and Engineering at Harvard University and Director of the Harvard University Center for the Environment. He also co-directs the Science, Technology and Public Policy Program at the Belfer Center for Science and International Affairs at the Harvard Kennedy School.

Dan's interests include climate change, energy technology, and energy policy. He has studied climate change over the broadest range of Earth's history, including how climate change and the chemical evolution of the atmosphere influenced the evolution of life in the past, and what steps might be taken to prepare for impacts of climate change in the future. He helped to develop the hypothesis that the Earth experienced a series of extreme glaciations, called "Snowball Earths," that may have stimulated a rise in atmospheric oxygen and the proliferation of multicellular animals. He is also interested in how we can use climate events in the geologic past to understand our current climate challenges. Dan has worked on a range of issues in energy technology and policy including advanced technologies for low-carbon transportation fuel, carbon capture and storage, and risks and opportunities of shale gas.

He was named a MacArthur Fellow in 2000. He served on President Obama's Council of Advisors for Science and Technology (PCAST) from 2009 - 2017, contributing to many reports to the President including those on energy technology and national energy policy, agricultural preparedness, climate change, and STEM education.


Tom Conforti: Dan before we get started on some of the policy issues, talk to us about how you became interested in climate science and public policy.

Daniel Schrag: There is an interesting personal history here. As an undergraduate at Yale I was a double major in Political Science and Geology. I had some vague idea that I wanted to work on natural resources, maybe mining or mineral resources or something like that, but what I did know was that I wanted to study science that had some policy relevance, and that was actually relevant to people. I wasn't quite sure what the issue was though, and it wasn't really until graduate school that I became interested in climate change in kind of a backdoor way. My thesis was actually indirectly related to climate change, and it led to a greater and greater focus. I was really lucky in my first faculty position at Princeton and then, a few years later, when I moved to Harvard, that I had the support of colleagues like John Holdren and Bill Clark, and many other people who helped me focus more and more on the policy dimensions of climate science.

Conforti: It is interesting how life ends up taking us down a path and that you end up here at the front of this climate change issue. So, let's start the high level discussion of what global warming and climate change is. When people refer to the goal of keeping global earth temperatures at 1.5 to 2 degrees Celsius warmer than pre-industrial temperatures, how was that goal established and what are they referring to?

Schrag: We've known for more than 100 years that the earth is warming because we're adding greenhouse gases to the atmosphere, primarily carbon dioxide, which comes from the burning of fossil fuels. We know the preindustrial level of atmospheric carbon dioxide of 280 parts per million is now well above 415 parts per million and rising all the time, and by mid-century, we will be somewhere close to 500 parts per million. From a geologic perspective, this is an extraordinary change and if we keep using fossil fuels over the next couple of centuries, we could easily see global temperatures rise from the preindustrial level by as much as four to six degrees Celsius which is not unprecedented geologically, as we know from analogs in our history. But this increase would be an unbelievable shock to both the natural system in terms of ecosystems and also to human society. We're talking about sea level rise of tens of meters, or maybe more. We're talking about unbelievable problems with extreme weather -- with heat waves, with all sorts of difficulties -- and that's just a huge challenge we want to avoid.

About 20 years ago, as part of the Conference of the Parties (COP), which was originally agreed to in the 1992 Rio Convention, participant countries began to talk about what the safe level of CO2 was. Now understand that, scientifically, there is no safe level. That's kind of an arbitrary concept, but the countries, from a policy dimension, centered around two degrees Celsius, as the kind of barrier between safe and unsafe. Now, unfortunately, I think this two degrees number has many problems. It gives the mistaken impression to a lot of people that 1.8 degrees is safe and 2.2 degrees is the end of the world. Of course, neither point is true. One degree is bad. Two degrees is worse. Three degrees is much, much worse, and four degrees is much, much, much worse, etc. If there are cliffs when the bad things happen sooner, we just do not know. And so, at COP, the European countries decided that two degrees wasn’t sufficiently ambitious. They wanted to push for 1.5 degrees. To me, all of this is well intentioned, but a little bit silly because, personally, I do not see the world having even a chance of stopping at two degrees. We are headed easily towards three, and I hope we can avoid four.

Conforti: Understood and as you said previously, that impact should not be taken lightly. There has been a great deal of emphasis by the Biden administration on combating global warming in the early stages of his presidency. He has talked about a whole government approach, spending plans, international re-engagement and global leadership. What is your early take on the administration’s efforts?

Schrag: Well, I think in terms of commitment and ambition, President Biden has done everything one could ask, and he's certainly appointed a lot of very good people who understand the issue and understand what we have to do and are thinking carefully and creatively about how to move the country down the path of decarbonization. I think the President’s cameo the other day getting behind the wheel of the Ford F 150 electric truck was fabulous. That's exactly what he should be doing from a symbolic perspective. In addition, the President has a proposal to provide resources for putting in charging stations to accelerate the deployment of electric vehicle (EV) technology by reducing the concerns about driving distance, and to use subsidies to increase EV sales. All these are important steps.

That being said, we have to remember that the President of the United States can’t do it all by himself -- the President requires Congress to cooperate. You know we've seen this pendulum swinging from Bush to Obama to Trump and now Biden and while executive action matters, what we really need to decarbonize the U.S. is long-term policy. That includes a price on carbon or equivalent. It could be sector specific or economy wide, but we need to send different sectors of the economy clear signals for what the effective price on carbon is going to be down the road, and that’s going to incent industries to invest in alternative technologies. If the airline sector, for example, knew the price on carbon that they would have to pay for using petroleum jet fuel 20 years from now is going to be very, very high, they would invest heavily in figuring out alternatives -- whether it's bio jet fuel or hydrogen fuel or whatever alternate technology. They would also be investing today. We're lacking those long-term signals. I fear we're not going to get those investments, and that to me is what's really needed here. In that sense, the victory hasn't yet been achieved.

You know that the infrastructure plan is ambitious, partly for extending the wind and solar tax credits and partly for a number of other things that relate to climate, but it hasn't made it through Congress yet. Let's see whether President Biden, after his 36 years in the Senate, still has the ability to get something through Congress in a way that President Obama wasn't able to do. That for me is the real test. The other thing that we could talk about is the ambition. I have to tell you that when President Biden announced the goal of 50% reduction in greenhouse gas emissions by 2030, I had mixed feelings. Everything I know about energy technology and the process of decarbonization tells me that we cannot achieve that goal. It is too aggressive, but I am not a politician. I am a scientist and a scholar, and I may be right that we cannot achieve it, but I cannot tell you that it was the wrong goal. Is it better to be overly ambitious and then fail to meet the goal or is it better to be slightly less ambitious and then be accused of under aspiration? I do not know what the right answer is.

Conforti: If you were to wave a wand that enabled us to reach the goal that we set for 2030, what magic steps would you create for us to get there? What are the essential elements to get to that 50% target?

Schrag: That 50% target is so difficult that I don't even know how to answer that question. Let me try to explain it this way. In 2014, the original goal that President Obama set in Beijing, with President XI, was a 26% to 28% reduction by 2025. To get to 26% to 28% from today will require essentially keeping oil consumption flat, as opposed to the steady growth we have witnessed over the last four years. If we were to keep oil consumption flat, and we were to get rid of essentially 80% of the coal use that we have today in the next five years, we could reach the 26% to 28% goal.

Conforti: And replace oil and coal with natural gas and renewables?

Schrag: A mix of natural gas, wind and solar. If we were to do that, we could get to that goal. The problem is that the next part gets harder. If you want to get more carbon out of the power sector, now you're talking about displacing natural gas, because there's not much coal left. And it takes more effort to get the same carbon reduction from natural gas because of its lower carbon content, and also because natural gas plants are more efficient than coal plants. Natural gas is about a third or maybe 40% of the emissions of coal plants per unit electricity. You have to work three times as hard to get the same unit of emissions reduction. So getting rid of natural gas is going to be a lot harder than getting rid of coal. And by the way, the electricity sector today is less than 30% of our total emissions. You have to start working on the other parts to reach the goal by 2030 -- only nine years from now. How much penetration of electric vehicles do you think we're going to have? Last year EVs accounted for only 2% of total car sales in the U.S. Even if that grows to 20% or 30% by 2030, that still means a tiny fraction of vehicles on the road are going to be EVs because of the turnover timescale.

Conforti: What about carbon pricing Dan? If your magic wand could create a coalescence around carbon pricing, would the market drive more immediate and meaningful reductions? Is that part of the solution?

Schrag: Absolutely. Carbon pricing or the equivalent is necessary. Remember it doesn't have to be a price on carbon directly. It could be a clean energy standard that essentially puts a price on carbon indirectly. If you mandate a certain fraction of clean energy from a particular sector, that imposes a price on carbon without actually setting a price. I think almost every climate policy expert would agree that some kind of effective price on carbon is critical, but let me bring in something that I think about as a geologist. That is the issue of timescale. I actually think that the real benefit of a price on carbon is in the slightly longer time scale not the immediate timeframe. You know if tomorrow you set a price on carbon on everything in the U.S., what would airlines do? The answer is, they would pay the tax because there is no alternative for them. What would a cement plant do? What would a steel mill do? They would pay the tax because all of the alternatives are wildly more expensive.

Conforti: And, in some cases, the technology is not sufficiently developed for some of the solution sets.

Schrag: Yes. The answer is that the power of a carbon price does not reduce emissions immediately. It's in guiding the long-term investment and the deployment of technology and infrastructure so that 20 or 30 years from now you're going to get there. This is what frankly the political discussion on the Left doesn't really understand, which is there is a timescale to decarbonization that is economically efficient. That isn't to say it may not be expensive -- it may be expensive. I don't think we know. It depends on technology and innovation but you can't innovate immediately. If you say airplanes have to get off petroleum in 10 years, I’m not sure the airline industry can do it. We need to think about that. It's really hard to see what do we do with ships? What do we do with trucks?

Conforti: Right. So to secure our longer term goals of zero carbon emissions and ultimately the extraction of carbon from the atmosphere, what will be the key enablers? Let us just go through a couple of contributing factors, the role of government versus the market. I assume both are essential.

Schrag: It has to be both. The market ultimately is the core of how it's going to work because all of this is going to be expensive, and we want to find the cheapest and best option. We don't want to pick the winners. We want to let the market pick the winners. That is the whole point. We don't know what is the right technology for airplanes or trucks or ships or cement plants. We're going to let the market figure that out, and that has to be the right answer. That being said, markets don't work just on their own to reduce carbon emissions, they need government policy. Government needs to put the rules of the road in place, and then the markets work to make it most efficient. I think that's the right answer.

I will say something else. I think that if there were one thing that I might nudge the Biden administration on, it's that they have paid a little bit too much attention, as has the whole political Left in the U.S., and just about the entire climate movement all over the world, to national emissions. It's become very funny. It's almost like Trump's America First. The truth is the climate system doesn't care what U.S. emissions are. It cares about global emissions. It is important in that the U.S. is the second largest source of emissions for the world, but the fact is, we should care about global emissions and not just global emissions in 2021 or 2022 or 2030 or 2050, we should care what cumulative global emissions are. Where I think that the U.S. and China and the European Union (EU) could be doing a lot more and paying a lot more attention is making sure that we lead effectively, and what that means is not just charging ahead towards zero emissions by 2050. Honestly, if we do that in a way that looks expensive to other countries, that's not going to help. We need to get to zero in a way that looks very attractive to other countries. That's much harder.

Conforti: I was trying to think what global governance structure exists today to pull off a coordinated and effective effort to help us reach our global climate goals. Since it is a global challenge, what role should the U.S. and other leading countries play?

Schrag: You know you honed in on exactly the right question. I think that climate change is going to demand some new form of global governance that we have not seen yet. Maybe it will grow out of the COP process. There was discussion about 10 years ago about large scale clean energy finance, and I think that's going to come back. I hope that at the conference in Glasgow, finance is going to be a big part of the conversation.

Unfortunately, one of the most devastating legacies of the Trump era that people haven't been talking about is the complete disdain that Americans have for foreign aid. Foreign aid used to be a big part of what the U.S. did for the world dating back to post-World War II. Trump essentially did away with foreign aid, and I think Biden may have a difficult time bringing it back to the level it was previously because I don't think there's a lot of enthusiasm within the electorate. My hope is that clean energy finance will be viewed differently than foreign aid. Clean energy finance is an investment that pays a return to all, and if we can invest in clean energy deployment around the world in cooperation with China and the EU, we can accelerate this transition around the world.

Conforti: I agree, global cooperation will be key. Getting back to the discussion around longer term goals. In the past, we've talked about the importance of innovation to really make progress against our climate goals. What are the key areas where innovation is underway but not quite meaningfully developed that you think are particularly promising as tools for combating climate change?

Schrag: I think the sector that everybody focused on initially, because it seemed like the easiest to get started on, was the electricity sector. Everything about electricity is far ahead of everything else, and in many ways, you know, wind and solar -- it's not that they can't continue to decrease their costs but they're mature. 75% of new generating capacity in the U.S. last year was wind and solar. Renewables are here, and they are price competitive. They benefit from federal tax credits and will continue to do so and that's a good thing, but they're mature technologies now, and they will be mature all over the world.

Next in line, I think you're seeing investment in things like batteries and that's interesting. I wonder how much they will actually play a role in decarbonization, but we'll find out. That's the nature of technology and innovation. We don't quite know what the answer will be. There's a bunch of other technologies that look like they're inevitable. They're just going to take a little time. EVs are the perfect example where I think enough of the large automobile companies have already decided that EVs are the future. The question is how fast. Is it going to be 20 years? Is it going to be 30 years? Is it going to be 40 years? It's no longer a question of “if” it's a question of “when”. 10 years ago that wasn’t the case. 10 years ago we thought that hydrogen fuel cell vehicles were going to compete with battery electric vehicles. I don't think that's true anymore.

Conforti: Is there a role for hydrogen in the battle plan against climate change?

Schrag: Today there's what I call a hydrogen bubble. I think there's a huge enthusiasm about hydrogen, but economically, there's a real tough road ahead. The question is where's the demand for hydrogen going to come from based on the cost. People have talked about hydrogen fuel cells for trucks, ships, airplanes, but they haven't taken off. I totally can see that there's a chicken and egg problem with regard to its infrastructure. How are you going to build the infrastructure and make sure the fueling stations are there, and then who's going to buy a hydrogen vehicle if they’re no fueling stations? I think it’s challenging because it involves a complete change of infrastructure. Therefore, I suspect that a combination of bio jet fuel and battery electric vehicles are going to win. The question is can bio jet fuel grow to supply the full demand for jet fuel in the world?

I would say that hydrogen for transportation, that is in trucks or ships or planes, just on a cost basis of the fuel, looks like only a factor of two or three times more expensive, but for heating applications, it is much, much more. People have talked about hydrogen for home heating or for use in chemical plants that require heat or to displace natural gas. But right now, it's like 20 times more expensive relative to natural gas and so that differential is much, much greater. It looks to me like using hydrogen in transportation has some advantages relative to heating; on the other hand, transportation has this infrastructure problem.

Conforti: How about natural climate solutions? We've talked about that in the past. What roles do natural climate solutions have to combating climate change in the future?

Schrag: Well, Tom as you know, since you sat through my course this Spring on natural climate solutions, part of the point of that course was to read the literature and try to make sense of all of the hype around natural climate solutions and see whether there was a real place for them. The argument is that forest, agricultural soils and a variety of other practices could take up a substantial portion of carbon emissions -- some studies claim as much as 30% of our carbon goals. I think it doesn't take long to convince yourself that those claims are wildly overstated. If we were really lucky, they might be 5% of the solution and after reading all those papers, I think your perspective is as valid as mine, but my perspective is that there's definitely potential for some of those practices, but I think there's also enormous risk of massive cheating in such a way that it undermines decarbonization efforts. For example, the Nature Conservancy talks about selling carbon credits on land that it's already conserved. That would go to what we call additionality or a variety of other concerns in that vein.

I think you know the corporate push to become net zero is embracing these technologies or these approaches, and I think that it's very dangerous for misuse. That being said, I just got back from a conference with all the corn ethanol producers in the U.S., and I think climate change is inevitably going to put more demand on land, and I think a lot of people who care deeply about conservation are not going to like this. I think that's going to make conservation more difficult because you're going to need to appropriate more land for energy, and I think if we're serious about decarbonizing jet fuel and shipping, I think the demand for biofuels is going to grow enormously. I just don't see how you avoid that. All the other technologies just look wildly expensive in comparison. That's good for farmers and landowners, but for people who care about conservation, it's trouble. I think we're going to have to figure out what's the right balance between protecting certain lands and investing heavily in certain lands to generate the kind of fuels we need to run the world.

Conforti: You mentioned Glasgow earlier, what would you consider a good outcome this November with the global meeting on climate change?

Schrag: My view of the COP process has always been that it's more of a reflection of what's going on, rather than a driver of what happens. The negotiations to me are more of the sort of encapsulation of all of the discussions and politics going on around the world and it's the codification of that. To me, I think too many people look to those discussions, including in Glasgow this coming year, as if there's going to be some great outcome. I think it is good for the countries to get together and for world leaders to have a little bit of pressure on them, but I wouldn’t expect too much. The one thing I would hope to get back on the agenda, and this would be what I said before, is to focus on clean energy financing around the world. I’d love to see the U.S. and the EU and countries in Asia, including China, invest in clean energy finance in rapidly developing countries around the world. I’m writing a paper on this right now.

There's what I call the renewables gap. If you look at countries like the U.S., we're about 12% wind and solar. That's behind most of the EU and the U.K., which are in the 20s up to mid-30s in Ireland. So, if you look at different countries around the world, the rich countries are 10% to 20% to 30% wind and solar. On the other hand, there are many, many countries like Indonesia, Pakistan, Ghana and many other countries in the world, where the number is essentially zero, and it's not because it's not sunny in Indonesia. So why aren't they building solar? It's cheap. They're doing it in India. There are a variety of market failures. Some of it is experience. Some of it is corruption. We need to solve this renewables gap and actually get all of these countries on a road to much deeper penetration of wind and solar.

In any low carbon scenario, the electricity sector, as you know, grows enormously and at least half of that electricity will need to come from wind and solar. The scenarios can differ. Some of them have 60% renewables; some have 80%. Honestly, I don't believe we know today how much we can handle, but we need to be at least 50%, and since we're 12% today in the U.S. we have much work to do. It's straightforward. We just have to keep building. These other countries haven't even started down that path yet so let's get them on that path. With more countries doing this, the bigger the market for wind and solar, the lower the price will be. I think there's a really good reason to help a lot of these countries that are developing quickly start to build out the renewables. That's a “no regrets” strategy. It doesn't matter what technological innovation occurs, whether it's carbon sequestration or advanced batteries or EVs or whatever it is, every low carbon energy system requires an electricity generation system with at least half wind and solar. That's a core to everything and we need to help countries get there.

Conforti: Agreed. Before closing, we have not used the word adaptation yet. Where does adaptation fit in the battle against climate change?

Schrag: Adaptation is critical. We're doing it all the time. As you know from taking my class last fall, the timescales of climate change are a lot longer than people think. Greenland’s ice sheet isn't going to stop melting every Summer just because we get to zero emissions. It's going to keep melting probably for millennia. Unfortunately, we've probably already destabilized it to the point where it's going to melt completely. The fact is it's going to accelerate, and it's going to be a problem for our grandchildren and our great grandchildren and for generations to come. Whatever we do on mitigation, adaptation is going to be something that is a legacy of the 150 years of human society we've made an imperative.

The question is how much do we invest in adaptation. Humans, in general, are pretty bad about doing things in advance. Once there's a big storm like after Hurricane Sandy hit New York, then for a brief few months Mayor Bloomberg had a political window to install some policies that move forward on adaptation, but even six months later, the political support for those measures drops. People forget and they move on and they don't want to spend money on it. Here, in Boston, you know the cost of building a barrier that would protect the whole Boston Harbor is probably $10 or $20 billion. Nobody is going to spend that money on Boston Harbor to protect Boston from something that isn't going to maybe happen in the next 30 years and so that's a really hard problem.

In some ways, adaptation happens on its own -- storm by storm, event by event, fire by fire -- and the question is, can you make the cost to society overall lower by not just doing things in advance, but thinking about smart policies. A very interesting case that I’m thinking about is the PG&E case in California. We remember the huge fires last year across California and Oregon, but a couple of years earlier, there was the deadliest fire in California -- the Camp Fireand PG&E was held responsible because of California law. A utility can be held responsible, even if there's no negligence, if it can be shown that their equipment caused the fire. There was a huge court ruling against them so PG&E declared bankruptcy. The question is, what does that mean when a public utility declares bankruptcy? Eventually those costs still go to somebody. It goes to the rate payers and that doesn’t necessarily decrease the risk of fire in California.

The question is when are we going to confront the fact that people are living in harm's way. Whether it's the people living on the outer banks in North Carolina or people living in the woods in California. Maybe the cost of living in the woods needs to include the cost of running underground wires and the cost of demanding that people clear a fire barrier around their home which people in Paradise California didn't want to do. They wanted to live with the trees in the woods. The problem was it was a huge fire risk and a terrible tragedy, but it was totally foreseeable. So you know, this is a little bit like floods on the Mississippi where, in the aftermath of the floods, people are told they can't rebuild their homes in the floodplain. They have to move but doing that on the coasts where real estate is very valuable is tough, and every time that someone tries to raise the rate for federal flood insurance, we hear Chuck Schumer oppose it, because many of his constituents on Long Island are going to get hurt financially. This is a really hard problem. The one thing to know, though, about adaptation, is that it will happen. We will adapt. It's a question of how much we're going to pay for it.

Conforti: Right and also the timing of adaptive measures. Following up on that thought, is Federal disaster support creating a disincentive to taking more timely climate adaptation measures?

Schrag: If we paid some in advance, took some precautions and invested in preparedness, we would save money in the long run. If people don't want to do that and pay those rates, that's fine. Their homes may get impacted and they might have to suffer the consequences. So far, we've had federal disaster insurance bail out cities when terrible tragedies have happened. We've come very close to the Federal Government not bailing out disasters and, by the way, this actually happened in Puerto Rico where Donald Trump really refused to pay for the full cost of Hurricane Maria. It was also true after Hurricane Harvey in Texas, where the government almost didn't come through but eventually they did. It was true regarding Hurricane Sandy in New York, where the Republicans in Congress didn't want to approve money for Hurricane Sandy, and it was Chris Christie, then Governor of New Jersey, who made a big stink and eventually got the money for that. I think in the next five years, we're going to see the failure of the federal safety net and then what happens when people know that they are on their own? It's going to be an interesting question.

Conforti: Dan, in closing, what's your source of optimism that while the battle will be long, as time goes on, we will defeat the threat of climate change?

Schrag: I don't know that we're going to defeat this threat. I know too much about the timescale of this and how much inertia there is in the system already. I’m not sure what defeat means.

My optimism really comes in the incredible ingenuity of humanity. I really believe that especially under crisis, humans are incredibly adaptive, and I think this century is going to be the most creative in responding to climate change. I think it'll be the most creative architecturally, agriculturally, and maybe even in terms of governance. You know we were talking about global governance earlier, and I think that's not because of altruism or you know some global consciousness that's going to arise, I think it's going to come out of necessity. H.G. Wells, in his book the Time Machine, had a great quote, “We are kept keen on the grindstone of pain and necessity.” I think there's a lot of truth to that, and I think humans are incredible. I think we will do incredible things in this century. Unfortunately, I also think that many humans will suffer, and one of the questions in my mind is will we rediscover, at least in the U.S., the compassion that we have, or we should have for the rest of the world. We seem to have lost some of that, and I hope we get that back.

Conforti: What a great thought to end our discussion! Thanks Dan for your thoughts today.


About the Author:

Tom Conforti

Tom Conforti is a Senior Fellow at Harvard’s Advanced Leadership Initiative (ALI). He joined ALI after 35 years in corporate America at companies including the Walt Disney Company, Pepsico, Dinequity and most recently Wyndham Worldwide, a leading hotel and resort company. Tom's focus at ALI is at the intersection of climate change and private enterprise. In addition to his corporate roles, Tom was elected to the Board of Finance of Stamford, Connecticut and served on a number of non-profit boards including Neighborhood Housing Services of Stamford, the Chandler School of Pasadena, California and the Flintridge Preparatory Board of La Canada Flintridge, California.


This interview has been edited for length and clarity.
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