Should the United States Be Back in the Paris Climate Accord?

Climate change is one of the most serious issues of our time, and when President Trump announced on June 1 he was withdrawing the U.S. from the Paris climate accord, it set off debate about the merits of the decision. We asked three alumni experts what they think.

Judah Cohen Ph.D. ’85, GSAS ’94
Cohen is director of seasonal forecasting and principal scientist at Atmospheric and Environmental Research. In addition to his research interests, Cohen is leading AER’s development of seasonal forecast products for commercial clients. Cohen also has a research affiliate appointment in the civil and environmental engineering department of MIT.

My simple answer is yes. The science is conclusive that the earth is warming, that anthropogenic activity is contributing to that warming and the warming is most likely to continue. It is also probable that a warming planet will have detrimental consequences for society, especially in the United States, which has a nearly optimal climate for supporting a thriving society. Therefore, I do believe that it is in the United States’ interest to support global efforts to reduce greenhouse gas emissions, to stabilize the climate and to prevent runaway warming. And to that end, it is to the benefit of the U.S. to participate in the Paris Climate Accord in a concerted and global effort to reduce greenhouse gases and other human activity that contribute to rising temperatures.

However, there is a part of me that believes that it is preferable that President Trump withdrew the U.S. from the accord. The agreement was voluntary and not enforceable. It is clear that the current administration is not persuaded by the science or scientists on this issue and is not motivated to make policy that incentivizes reducing greenhouse gases. The goals and actions of the administration are to facilitate greater production and consumption of fossil fuels regardless of whether the U.S. is a signatory of the accord — so better to dispense with the pretense that the administration is a responsible steward of the environment. By renouncing the U.S.’ participation in the accord, the citizens of the U.S. and the global community know exactly the priorities of the administration on the issue of climate change and efforts to mitigate potential deleterious impacts. The hope is this will motivate concerned people, communities and companies to take action that changes the trajectory of the U.S.’ contribution to anthropogenic climate change in spite of the current administration.

Meghan F. Cronin Ph.D. ’86
Cronin transferred from UC Berkeley to the College in 1983 when it began admitting women, earning a B.A. in physics in 1986 and a Ph.D. in oceanography from the University of Rhode Island in 1993. She leads the Ocean Climate Stations group at the NOAA Pacific Marine Environmental Laboratory and is a science editor for American Geophysical Union’s Geophysical Research Letters. The opinions stated here are personal and do not necessarily reflect the views of the U.S. government or NOAA, but are consistent with the position of AGU.

Yes! I get that Midwesterners are unimpressed by a two degrees Celsius warming; their temperature range is more than 50°C. A 2°C change is no sweat. Consider, however, that it is not just the mean — the whole probability curve is shifting. Heat waves will be hotter; winters will be shorter. Also this is a global average target. Regionally, we can expect much larger temperature changes. Currently the Arctic is warming at more than twice the rate of lower latitudes, and the least amount of winter sea ice during the satellite era was observed in March 2017, breaking the record for a third year in a row. If sea ice melting continues at the current rate, it may be ice-free during the summers in as little as a decade. That will be a game changer. With a dark water surface instead of white sea ice, sunlight will be absorbed rather than reflected and the heating of the Arctic will accelerate. The “polar front” between warm mid-latitudes and the rapidly warming cold Arctic will then become weaker, which will certainly have an impact on weather patterns, storm tracks and rainfall distributions. We have chosen a future where we, and our children, will have to adapt. Where plants — living organisms that make up our food source, and the ecosystems that support them — will be challenged by new conditions. Where our water sources might be threatened. Let’s be clear: We are choosing to adapt to these changes because we refuse to adopt modest lifestyle changes right now, changes that some might consider part of progress. I’m a climate scientist and I’m scared. Yes! The United States should be back in the Paris Climate Accord!


Michael B. Gerrard ’72
Gerrard is the Andrew Sabin Professor of Professional Practice at the Law School, directs the Sabin Center for Climate Change Law and chairs the faculty of the Earth Institute. He formerly chaired the American Bar Association’s 10,000-member Section of Environment, Energy and Resources. Gerrard has been a member of the executive committees of the boards of the Environmental Law Institute and the American College of Environmental Lawyers. He is the author or editor of 11 books, most recently Global Climate Change and U.S. Law (with Jody Freeman).

The United States is the source of about one-quarter of the greenhouse gas emissions in the atmosphere — more than any other country. We also have among the highest per capita emissions. There is increasing evidence (some of it developed by scientists at the Earth Institute) that these emissions are already contributing to extreme weather events and will pose grave dangers to our children and grandchildren. Thus the United States has a special responsibility to act.

President Trump’s proposed withdrawal from the Paris Climate Accord and his moves to cancel the Clean Power Plan and other federal efforts to reduce emissions are an abdication of that responsibility.

Paris set ambitious targets but soft methods to achieve them. Each country picked its own goals and methods of meeting them, with no enforcement mechanism if they failed. Trump and his EPA chief, Scott Pruitt, willfully ignored the facts in calling Paris a bad deal for the United States.

Some fear that the U.S. withdrawal will allow China to seize international leadership on the climate issue, which is ironic on many levels. So far no other countries have announced they will also drop out, but Trump’s action will embolden political forces in other countries that oppose climate action and, like Trump, want to cling to a fossil fuel-based economy and ignore the environmental, public health and economic benefits of transitioning to a system of clean energy, using technologies whose costs are plummeting. Fortunately, when environmental rationality returns to the White House (I hope with the 2020 election), the U.S. will be welcomed back into Paris. Meanwhile, though, we are losing precious time.