Bennet, Colleagues Criticize Trump Changes That Substantially Understate the Costs of Climate Change, Putting America’s Economic Health at Serious Risk

GAO Report Released by Senators Found That Administration Has No Plan to Address Recommendations from Leading Experts

Grand Junction – In a report released by Colorado U.S. Senator Michael Bennet and six U.S. Senate colleagues, the Government Accountability Office (GAO) found that President Donald Trump’s changes to the federal government’s core measure of the costs of climate change, the social cost of carbon, mean “current federal estimates [of climate effects] . . . are about 7 times lower than the prior federal estimates.” Despite a recommendation from the National Academies of Science, the Trump Office of Management and Budget (OMB) – the agency responsible for overseeing the calculation of the social cost of carbon – has no plans for updating the key measure to reflect the best available science, GAO concluded.  

The findings stem from a December 2017 request by Bennet and U.S. Senators Sheldon Whitehouse (D-R.I.), Jeff Merkley (D-Ore.), Ben Cardin (D-Md.), Elizabeth Warren (D-Mass.), Kamala Harris (D-Calif.), and Dianne Feinstein (D-Calif.). 

“This GAO report is further proof of the Trump Administration’s failure to listen to experts and address the climate crisis,” said Bennet. “The report lays bare the White House’s continued refusal to accurately account for the cost of climate pollution in federal policy. By putting politics over science, this administration continues to imperil our future by downplaying the dangers of climate change to Americans’ health and safety.” 

“Climate change is a massive threat to our economy. That threat will only grow in years to come, even if we take the action necessary to avoid the worst effects of climate change. We need a social cost of carbon pegged to the best available science to plan and adapt,” said Whitehouse.  “Instead, the Trump administration undermined the social cost of carbon, and then stuck its head in the sand when the federal government’s top scientists recommended implementing important changes. Shutting off the headlights of science and sound economics makes it more likely that we’ll drive straight off a climate cliff.”

“As we work together to rebuild our economy after this catastrophic public health crisis, we have to focus on putting in place critical building blocks for a strong, prosperous future,” said Merkley. “If we don't include bold climate action guided by good science and data in our recovery, we will just be teeing up the next public health and economic catastrophe. People are looking back now wondering why we weren't better prepared for a pandemic experts told us was overdue. We can't afford to repeat these mistakes.”

“When we document the true cost of the climate crisis, it becomes apparent that investing in a comprehensive response is the best investment we can make,” said Cardin. “The State of Maryland has identified 33 bridges that are highly vulnerable to sea level change, 172 bridges highly vulnerable to storm surge, and 102 bridges highly vulnerable to precipitation change on Maryland’s highway network. The costs of maintaining infrastructure is rising rapidly in Maryland and throughout the country. We must have honest and accurate accounting to manage the risks and make the necessary investments in response to the climate crisis.”

“Climate change continues to hurt our communities and our economies, and the Trump administration’s efforts to understate the social cost of carbon are both dangerous and irresponsible,” said Warren. “We must listen to the scientists and experts and act now to tackle the climate crisis head-on.” 

“President Trump and his administration are failing to take the threat of climate change seriously,” said Harris. “The administration’s decision to ignore our country’s top scientists threatens our economy and our ability to address the climate crisis.  We can’t take the bold action necessary to address the climate crisis if we are not adequately accounting for the cost of greenhouse gas pollution.  Yet again, this administration has put polluters over people.” 

“We have to take the threat of climate change seriously,” said Feinstein. “This GAO report makes it clear the administration’s formula for accounting for the cost of greenhouse gas emissions minimizes the risks.  Ignoring or distorting the true costs of climate change won’t make the problem go away, it will just make it harder to respond to the very real challenges we’re facing.” 

In 2017, President Trump issued an executive order disbanding an important interagency working group charged with formulating the social cost of carbon and withdrew the guidance working group had issued. They have instead made changes that resulted in a severe downtick in the value of the social cost of carbon.  

The Trump Administration changed two key assumptions when calculating the social cost of carbon. First, it claimed to look at domestic economic effects of carbon pollution instead of global effects – disregarding expert concerns that this purportedly domestic estimate was flawed, failed to capture important impacts to Americans, and ignored the reality of our global economy. Second, it preferred a higher discount rate for calculating the social cost of carbon. The discount rate discounts the present value of things that happen in the future based on a percentage; a higher discount rate devalues the harms and losses that climate change will impose on future generations.   

According to the new GAO findings, Trump’s changes mean “the current federal estimates, based on domestic climate damages, are about 7 times lower than the prior federal estimates that were based on global damages (when both prior and current estimates are expressed in 2018 U.S. dollars and calculated using a 3 percent discount rate).” The GAO also found that Trump’s OMB has no plans for updating the methodologies used to develop the federal estimates, notwithstanding an extensive set of recommendations from the National Academy of Sciences, nor does it plan to task anyone in the federal government with doing so.


Bennet and the senators had asked the GAO to look at states and other countries’ social costs of carbon, the Trump Administration’s justification for dramatically changing the way it discounts the costs or benefits of regulation change affecting carbon pollution, and the rationales that have been used to support various discount rates in assessing the social cost of carbon. 

The GAO’s findings point to a lack of trust in the Trump Administration’s tweaks to the social cost of carbon among other governments. The report found no state that uses the Trump Administration’s lowered social cost of carbon values, while nine states – including New York, California, Minnesota, and Nevada – have continued to use the values set by the Obama Administration. Of the countries the GAO studied, both Canada and Germany have developed their own values, which include global damages and lower discount rates akin to the Obama formulation. In all, the states and countries evaluated showed that the Trump Administration numbers are outdated and out of step with current science.    

In 2017, Bennet introduced the Pollution Transparency Act to standardize the metric used by federal agencies to measure the cost of climate pollution, countering a directive from the Trump Administration to agencies to ignore existing metrics. In June 2019, Bennet reintroduced this legislation as the Carbon Pollution Transparency Act making important updates, including requiring all costs of climate change to be considered, adjusting the values for inflation, broadening the group of agencies involved in determining this metric, and requiring impacts in environmental justice communities to be considered. This legislation is cosponsored by the majority of requestors of the GAO report alongside 11 other Senate Democrats.   

The full report is available HERE.