Can We Trust Rex Tillerson on Climate Change? No.

Donald Trump’s nominee for Secretary of State, Rex Tillerson, is no stranger to saying one thing in public on climate change and saying contradictory things later. Tillerson, who spent the last 10 years as CEO of ExxonMobil, staked out conflicting positions in his answers to Senator’s written questions as compared to the views he publicly expressed during his nomination hearing two weeks ago before the Senate Foreign Relations Committee. There seems to be an emerging trend where nominees say one thing in their hearing, the nominee walks back some of those things said under oath, and the White House under President Trump issue directives that contradict the nominee.  

The fact that Tillerson’s private answers are more backward-looking about the science of climate change and the United States’ role in international climate agreements should worry not just those who care about climate change, but anyone who thinks we should be able to trust our nation’s top diplomat to uphold certain ideals without worrying that he will act differently behind closed doors.

Here are three of the most alarming contradictions from Tillerson’s public hearing and private responses to senators, and evidence that his confirmation as Secretary of State could seriously undermine the U.S. national interests that he has firmly pledged to promote.

1. Dangerously deceptive on climate change science

Tillerson intentionally distorts the science of climate change while openly acknowledging, “I am not a climate scientist.” He agrees with the scientific consensus that burning fossil fuels leads to more greenhouse gas emissions, yet he blatantly lies and contradicts climate change experts by saying that pollution from fossil fuels are not the “key” factor in rising temperatures. This dangerous view flies in the face of scientific evidence.

Tillerson’s public statements indicate he is either unaware or misinformed on the latest climate research and predictions:

“The increase in the greenhouse gas concentrations in the atmosphere are having an effect. Our ability to predict that effect is very limited.”

And his private statement only doubles down on questionable claims used by climate change deniers:

“I agree with the consensus view that combustion of fossil fuels is a leading cause for increased concentrations of greenhouse gases in the atmosphere. I understand these gases to be a factor in rising temperatures, but I do not believe the scientific consensus supports their characterization as the “key” factor.”

Here is a statement from the Intergovernmental Panel on Climate Change (IPCC) based upon reams of peer-reviewed studies from scientists who actually study this issue:

“It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in GHG concentrations and other anthropogenic forcings together.”

When the IPCC uses the term “extremely likely” it is their highest level of confidence in the conclusion—representing a greater than 95% probability. So while Tillerson may not “believe” that fossil fuels are the key factor driving rising temperatures, the scientific community is virtually certain in this connection.

It’s hard to fathom that Tillerson as head of ExxonMobil wasn’t briefed on these scientific conclusions, and harder to believe that he is not being willfully deceptive by refusing to acknowledge the major role that climate pollution from fossil fuels plays in rising global temperatures.

2. Dangerously deceptive on U.S. international cooperation on climate change

Tillerson stated during his public hearing that “it’s important that the United States maintain its seat at the table” in international climate change negotiations. His former company has continued to support the historic Paris Agreement which secured meaningful climate commitments from all major countries in the world. Some could read his “seat at the table” statement as hinting that he will have the U.S. remain a participant of the Paris Agreement.    

However, in his private responses to senators, Tillerson seems to walk back his commitment to engagement by saying:

Mere membership in an international agreement does not by itself convey global leadership or credibility.”

He goes further in his private answers to say that he would:

“conduct a review of the Paris Climate Agreement and the United States climate target to determine whether it advances national interests.”

Since ExxonMobil endorsed the Paris Agreement while he was at their helm is he now implying that ExxonMobil supported something that might not be in the national interest of America? His public statement was thus quite deceptive—suggesting that the United States maintain a “seat at the table” in international climate agreements but privately expressing that this “mere membership” will mean nothing. It appears that  Tillerson could care less about global leadership or credibility on America’s climate commitments.

3. Dangerously deceptive on ethical questions

In his public hearing, Tillerson refused to answer any questions about the controversial nature of ExxonMobil’s efforts to conceal scientific research related to the risk of climate change. Several senators asked questions regarding ExxonMobil’s climate deceptions and the $33 million Exxon had donated to organizations spreading misinformation about climate change. Tillerson asserted that his resignation on December 31, 2016 from a 40-year career at ExxonMobil meant that he was no longer on the hook to answer any questions about Exxon ever again. You can judge part of the exchange with Senator Kaine for yourself:

Senator Tim Kaine: And let me ask you, do you lack the knowledge to answer my question or are you refusing to answer my question?

Rex Tillerson: A little of both.

However, in his private responses, Mr. Tillerson continued to defend ExxonMobil’s position and linked to Exxon’s corporate statements regarding the legal case against Exxon.

Mr. Tillerson worked at Exxon for forty years. Yet, he refuses to answer serious allegations about the record of the company. It’s a company he headed for the last decade. Exxon has a long record of human rights abuses, climate deception, and environmental destruction that Tillerson refuses to address. Tillerson has no record in government service, and refuses to answer questions about his forty years with Exxon. So we can only look at his past record of performance heading Exxon.

We’ve seen decades of environmental catastrophe in Africa due to companies like Exxon maximizing profits while leaving local communities to pay heavy price tags in dirty water, destroyed croplands and severe health impacts. And now, we’re reading in his responses to senators' questions that Tillerson qualifies support for providing renewables to world’s poorest depending on whether “they are sufficiently economic to deploy.” Exactly what type of criteria would Mr. Tillerson use to judge aid is “sufficiently economic?” Exxon had not sufficiently factored in environmental, health or other costs in their decisions, what will Tillerson—who used to run Exxon—factor into his decisions?


It remains an unanswered question whether Tillerson possesses the ethical grounding to conduct international diplomacy—especially when his answers to key questions are constantly changing. How do we accurately judge a candidate who answers questions from Senators and the American public with such a contradictory and confusing set of responses? He seemed to backtrack or further muddy the waters on statements he made during his public hearing regarding climate science and climate action. What really does he stand for? We hold no hope that he will suddenly become a climate champion, and his responses to the latest round of questions confirm that he is the wrong person for this job as Secretary of State.

About the Authors

Han Chen

International Climate Advocate, International and Climate & Clean Air programs

Brendan Guy

Manager, International Policy, International program

Jake Schmidt

Director, International program

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