Composite of a forest, the UK in lights, a cityscape, and icebergs

Princeton experts identify priorities for Glasgow climate summit and global actions going forward

Hundreds of leaders and thousands of climate scholars from around the globe will gather in Glasgow, Scotland, for COP26, the 2021 United Nations Climate Change Conference, from Oct. 31 to Nov. 12.

Most experts believe this year’s meeting — the biggest climate summit since the Paris Agreement was signed in 2015 — has a unique urgency because it is the deadline for countries to present their plans to cut emissions and make it possible to limit our planet’s warming to only 1.5 degrees Celsius.

Princeton has been at the forefront of climate change research for more than a half-century, and as the world prepares for the summit, some of the University’s many environmental experts — scientists and scholars who are devoting their careers to solutions — are speaking to the moment.

“This is a very, very important meeting for humanity,” said V. “Ram” Ramaswamy, who has developed some of the world’s leading climate models and was one of the many Princeton scholars who shared in the Nobel Peace Prize awarded to Al Gore and the Intergovernmental Panel on Climate Change in 2007.

“It’s been almost 30 years since Rio [the seminal 1992 gathering of the United Nations Conference on Environment and Development in Rio de Janeiro],” Ramaswamy said. “And with every decade that passes, the climate crisis is more and more of a serious concern for society, and more and more difficult to cope with.”

The United Kingdom, the host nation for the Glasgow summit, has published four goals for the upcoming two-week conference: We spoke with Ramaswamy, climate visionary Michael Oppenheimer, 2021 Nobel Laureate Syukuro “Suki” Manabe and other Princeton experts about what to expect, why the goals matter now, and what they hope will be accomplished. None of the quoted experts will be flying to Glasgow to attend the summit in person, but they are all keenly interested in its outcomes.

Goal 1: Secure global net zero by mid-century and keep 1.5 degrees Celsius within reach

Our expert voices: Emily CarterJesse JenkinsV. “Ram” Ramaswamy

The reason we are trying to limit warming to 1.5 degrees is that this already reaches a threshold where climate change and its related impacts — fires, intense storms, droughts — are causing widespread damage to life and property. If the temperatures rise to 2 degrees, the severity of losses due to extreme events will scale up,” said Ramaswamy, director of NOAA's Geophysical Fluid Dynamics Laboratory, and a faculty member in geosciences and atmospheric and oceanic sciences. “Reaching net zero emissions over the next few decades is plausible, although it represents a strong challenge.”

“The current power grid took 150 years to build. Now, to get to net-zero emissions by 2050, we have to build that amount of transmission again in the next 15 years and then build that much more again in the 15 years after that. It’s a huge amount of change,” said Jesse Jenkins, assistant professor of mechanical and aerospace engineering and the Andlinger Center for Energy and the Environment, and a lead scientist on the Net Zero America project.

“If we don't start making progress on the first goal, everything's going to get much worse,” said Emily Carter, Princeton’s Gerhard R. Andlinger ’52 Professor in Energy and the Environment and a professor of mechanical and aerospace engineering at the Andlinger Center for Energy and the Environment. “We have to accelerate getting the whole world off coal. We need to electrify everything we can and get the electricity from renewable sources, or at least carbon-free sources like nuclear. Fission power now, and eventually fusion power, are going to be critical.”

She continued: “The reason I say ‘Electrify everything’ is because the energy that comes in the form of electricity is just so much more efficient than the amount of work we can get out of burning fossil fuels. Burning fossil fuels loses a lot of useful energy as waste heat, in addition to producing carbon dioxide. Plus oil and natural gas extraction also emits methane, which is 20 times worse as a greenhouse gas than carbon dioxide.”

Carter said that her rising sense of urgency comes from the wildfires raging in California, Siberia and Australia, flooding in Germany, more severe hurricanes and typhoons, and countless other climate-linked disasters. “Everyone knew that those were coming, but no one thought they would come so soon,” she said. “It's not enough to worry about transitioning off of fossil fuels, we have to do something about the fact that there is already far too much carbon dioxide and methane in the atmosphere.”

She proposes harvesting carbon dioxide from the atmosphere and oceans, then converting it into profitable products, from liquid fuels for airplanes and cargo ships to limestone-like carbonate minerals to carbon fibers used in cars and airplanes.

“We’re much more likely to see acceptance of extracting carbon dioxide from the atmosphere or power plants if there can be an economic incentive for them. And the fact is, there are ways to produce high-value forms of carbon.” She wants to power this work using excess renewable energy. “The word excess is important.” On sunny days in California and the southwest, or windy nights in the Midwest, solar and wind power plants produce more electricity than the area around them needs. “We can set up plants to take advantage of that excess renewable electricity, rather than let it go to waste, which is currently what's happening,” Carter said.

Ultimately, the world needs this goal adopted, Ramaswamy said. “The commonality of interest in the well-being of all of the world's citizens should guide the leaders of the world to formulate realistic, equitable, definitive pathways for reducing emissions and atmospheric concentrations.”

Suki Manabe, Anu Ramaswami, Ram Ramaswamy, David Wilcove

Suki Manabe, Anu Ramaswami, Ram Ramaswamy, David Wilcove

Goal 2: Adapt to protect communities and habitats

Our expert voices: Elie Bou-ZeidAnu RamaswamiDavid Wilcove

“There is no machine that captures carbon as effectively — and with as many side benefits — as a tree,” said David Wilcove, a professor of ecology and evolutionary biology, public affairs, and the High Meadows Environmental Institute. “And an intact, healthy coral reef can do a terrific job protecting coastal communities from storm surges, while also sustaining a productive fishery for those people. So, not destroying natural ecosystems, and repairing or restoring the ones we’ve damaged, should be near the top of the list of climate solutions.”

He continued: “Policymakers need to be more aggressive about protecting and restoring nature. It’s the restoration part, in particular, where things get tricky. For example, it’s possible to sequester carbon in a planted monoculture of non-native trees, which will do little to sustain native wildlife. Conservation scientists can contribute to solving the climate crisis by highlighting the ways in which human well-being depends on the well-being of nature and by providing advice on how to restore natural ecosystems in ways that also contribute to solving an equally urgent crisis: the loss of biodiversity. Either crisis, left unchecked, will do us in.”

Experts are under no illusions about the scale of the challenge facing them. “This is just not an easy problem to solve,” said Elie Bou-Zeid, a professor of civil and environmental engineering. “It involves an extremely large range of agents and stakeholders, as well as myriad natural and human made systems. We have inherited a rigid infrastructure that is unable to deal with the new climate and the extremes it will generate.”

He does see signs of progress, he said. “The past decade has seen a significant increase in large interdisciplinary projects focusing on understanding and improving resilience. At the local government level, most cities and states are now developing resilience plans, particularly to counter the threats of hurricanes, floods and extreme heat. At the federal level, the progress has been unsteady. But the bigger question is, ‘Is this progress enough?’ While New York City is at the forefront of planning for weather extremes, hurricane Ida still caused massive damage in the city and in our state.”

“Cities are progressing where nations are getting stuck,” agreed Anu Ramaswami, Princeton’s Sanjay Swani '87 Professor of India Studies and a professor of civil and environmental engineering, the Princeton Institute for International and Regional Studies, and the High Meadows Environmental Institute. She also directs the Chadha Center for Global India. “There's a lot of collaboration through networks of cities that transcend national boundaries.”

She pointed to C40 Cities, a network of 97 megacities that are home to more than 700 million people, and ICLEI – Local Governments for Sustainability, a global alliance of more than 2,500 local and regional governments committed to sustainable urban development. She noted that some cities are larger than many countries. Tokyo, for instance, has 14 million citizens in city limits, and nearly 30 million in the surrounding area. “Cities are forging collaboration without getting hung up on some of the things that nations get hung up on,” she said.

“In some ways, cities are more eager to confront climate change than federal governments because they are the ones that get called when you have catastrophic storms or people collapsing from heat stroke,” Ramaswami said.

Goal 3: Mobilize finance

Our expert voices: Nicolas Choquette-LevyChris GreigMichael Oppenheimer

“A net-zero world is more capital-intensive than what we have been used to,” said Chris Greig, the Theodora D. ('78) and William H. Walton III ('74) Senior Research Scientist in the Andlinger Center for Energy and the Environment. “Essentially, we are transitioning to a system characterized by higher upfront capital, with lower ongoing fuel and operating costs. So, for me conversations on the financing challenge are overlooking a critical issue.

“While there is a growing trend to so called ESG investments — investing in companies that are making responsible choices with respect to the environment, social issues and corporate governance — this essentially describes the process of fund managers and lenders transitioning their portfolios to have a lower carbon footprint,” Greig said. “This is great in principle, but the majority of these funds are looking to acquire small positions among diverse portfolios of companies whose operational assets already have a lower carbon intensity. That isn’t providing the tens of trillions of dollars of at-risk funds to develop and build those assets.”

Greig suggests that help could come from a surprising direction: fossil fuel companies. “The traditional oil and gas (and other) companies are a largely untapped resource for the transition,” he said. “Their balance sheets, their capital allocation discipline, and most importantly, their tens of thousands of top-class engineers and project managers are not being mobilized. They have for the most part remained on the sidelines, cautiously dabbling. The transition will stand a better chance when that situation changes.”

Ultimately, governments need to take a larger role, Greig said. “Looking forward, I think we need to see governments taking a much more hands-on approach to reduce the risks and uncertainties around the transition, to an extent that we can see a massive acceleration of risk capital allocation by the private sector.”

Mobilizing finance also requires remediating existing harm as well as preparing for the future, said Nicolas Choquette-Levy, a Ph.D. candidate in the Science, Technology, and Environmental Policy program within the Princeton Institute for International and Regional Studies.

“While much of international climate finance goes to help countries reduce greenhouse gas emissions, there is a significant need to increase financing for adapting to the effects of climate change,” Choquette-Levy said.

In recent years, each corner of the world has already had to contend with the devastating effects of more frequent and severe floods, droughts, and other climate-linked events, which we can expect to worsen as the planet warms. Climate finance has started to provide countries with the means to prepare for these risks,” he said. “But the current amount of financing is not nearly enough. Industrialized countries have so far failed to meet the previous target of $100 billion in climate financing, but according to the UN Environmental Programme, they actually need to double or triple this amount at COP26 [the Glasgow summit]. This will be a crucial element of helping societies meet the rising costs of climate change this decade.”

When it comes to financing, the devil is often in the details, said Michael Oppenheimer, who has played a role in every major climate conference for three decades, and who has written or edited portions of every IPCC report since the first in 1991.

“It depends on whose accounting you believe,” said Oppenheimer, Princeton’s Albert G. Milbank Professor of Geosciences and International Affairs and the High Meadows Environmental Institute, and the director of Princeton’s Center for Policy Research on Energy and the Environment. “By some reckoning, public funds have leveraged sufficient private capital so that the commitment to $100 billion annually was nearly met recently. However, there are disputes about the accounting, and I am somewhat skeptical. It’s always the same problem: What would have happened anyway? What was just reprogrammed and is not new money? What’s just fake?”

He continued: “The truth is that such funding is important to developing countries, and they know that it’s not all that it is touted as, but both sides need to claim they walked away with something from the negotiations. By and large, that is the piece that is most important to developing countries, since they have largely gotten empty promises from the developed countries on how much the latter were going to reduce emissions. What’s really key is funding for adaptation by poorer countries, and how much is actually flowing to them for this and then down to where it matters.”

Carter, Grieg, Jenkins, Oppenheimer

Emily Carter, Jesse Jenkins, Chris Greig, and Michael Oppenheimer

Goal 4: Work together to deliver

Our expert voices: Elie Bou-ZeidSyukuro "Suki" ManabeMichael Oppenheimer

“Sometimes it seems that achieving any of the four goals remains far, far off in any meaningful rather than symbolic sense,” Oppenheimer said. “Because of this difficulty, climate summits now have more symbolic value than any effect they have on actually implementing emissions reductions and adaptation strategies that will ‘save the planet.’”

Manabe, who shared in the 2007 Nobel Peace Prize for Al Gore and the IPCC, won the 2021 Nobel Prize in Physics for his work developing the science of climate modeling. The climate models he created in the 1960s remain the backbone for all climate modeling work done around the world.

“It’s one thing to predict climate change; it’s another thing to decide what to do, given that prediction,” Manabe said. “Climate change is just based upon the laws of physics. It’s much easier to understand how the climate is going to change and why, which is the subject of my research. But climate change policy involves not only energy, but agriculture, the economy, politics — so you can easily imagine that to make a decision is a thousand times more difficult. So I have no intention of recommending specific actions, but I think people should understand the complexity before taking one action or another.”

“If an ambitious treaty comes out, and if all parties make a best-faith effort to abide by it, it can greatly accelerate the energy transition and the adaptation,” said Bou-Zeid. “Recall that people suffered greatly from climate variability and extremes before climate change manifested as a reality, so investments and efforts to increase resilience would be welcome even if we manage to curtail the worst prospect of future extremes.”

B. Rose Huber from the Princeton School of Public and International Affairs contributed to the reporting of this story.