John Holdren Photo

John Holdren

Teresa and John Heinz Professor of Environmental Policy
Office Address
79 John F. Kennedy St. Belfer Bldg 321
Holdren, John P. "Foreword." Titans of the Climate: Explaining Policy Process in the United States and China. Ed. Kelly Sims Gallagher and Xiaowei Xuan. The MIT Press, 2018, xi-xiv.


The United States and China together account for a disproportionate 45 percent of global carbon dioxide emissions. In 2014, then-President Obama and Chinese President Xi Jinping announced complementary efforts to limit emissions, paving the way for the Paris Agreement. And yet, with President Trump's planned withdrawal from the Paris accords and Xi's consolidation of power—as well as mutual mistrust fueled by misunderstanding—the climate future is uncertain. In Titans of the Climate, Kelly Sims Gallagher and Xiaowei Xuan examine how the planet's two largest greenhouse gas emitters develop and implement climate policy.