False! Trump Claims Paris Deal Would Only Make 'Tiny' Difference

In the Rose Garden on June 1, 2017, Trump said the Paris climate agreement would reduce global temperatures by only a "tiny, tiny amount."
In the Rose Garden on June 1, 2017, Trump said the Paris climate agreement would reduce global temperatures by only a "tiny, tiny amount." (Image credit: Win McNamee/Getty Images)

A comment that Donald Trump made yesterday in the White House Rose Garden when he announced the United States would pull out of the international Paris climate agreement was not based in science.

Trump said yesterday (June 1): "Even if the Paris Agreement were implemented in full, with total compliance from all nations, it is estimated it would only produce a 2/10 of one degree — think of that. This much….Celsius reduction in global temperature by the year 2100. Tiny, tiny amount."

The Paris Agreement, which went into effect Nov. 4, 2016, and now has 147 signatories, would have big impacts on global temperatures, climate scientists have said. [Trump Pulls Out of Paris Climate Deal: 5 Likely Effects]

The agreement's signatories aim to keep global warming below 3.6 degrees Fahrenheit (2 degrees Celsius) of preindustrial levels this century, with the more ambitious goal of keeping that warming to below 2.7 degrees F (1.5 degrees C). Signatory nations agree to make voluntary emissions cuts to meet these goals, saying those cuts will become stricter as time goes on. At the rate these cuts are progressing, an analysis by Climate Interactive found that those countries are falling short of meeting this 3.6 degrees F goal and rather would likely see about 6 degrees F (3.3 degrees C) of warming by 2100. Even so, that's well under the temperature increase projected if no deal were in place: 7.6 degrees F (4.2 degrees C).

Climate scientist Michael Mann, director of the Earth System Science Center at Pennsylvania State University, took particular exception to Trump's comment, tweeting yesterday: "Donald Trump just lied to the world. Paris accord WITHOUT further progress would cut warming by 1C. W/ ratcheting up, nearly 3C!"

Climate Interactive found that by not following through on its Paris climate commitment, the United States would spew an additional 1.4 gigatons of carbon dioxide into the atmosphere each year through 2025, as compared with the U.S. following through on its commitment.

Speaking at a roundtable discussion this morning (June 2) with Democracy Now, Mann schooled Trump a bit further on his comment:

"He was only off by a factor of 10, because [the Paris Agreement] will shave at least a degree Celsius and with proper ratcheting up, it will literally cut the projected warming in half, getting us onto a path where we could see stabilizing the warming below 2 degrees Celsius, what most scientists who study the impacts of climate change will tell you constitutes the level of dangerous interference with the climate."

Original article on Live Science.

Jeanna Bryner
Live Science Editor-in-Chief

Jeanna served as editor-in-chief of Live Science. Previously, she was an assistant editor at Scholastic's Science World magazine. Jeanna has an English degree from Salisbury University, a master's degree in biogeochemistry and environmental sciences from the University of Maryland, and a graduate science journalism degree from New York University. She has worked as a biologist in Florida, where she monitored wetlands and did field surveys for endangered species. She also received an ocean sciences journalism fellowship from Woods Hole Oceanographic Institution.