That one-degree difference would increase annual climate-related global economic damages—from coastal flooding, heat-related illness, and other harm—by an amount equivalent to roughly 1 percent of global economic output, the report concludes.
"To put this percentage in perspective, 0.9 percent of estimated 2014 U.S. Gross Domestic Product is approximately $150 billion. The incremental cost of an additional degree of warming beyond 3Â° Celsius would be even greater. Moreover, these costs are not one-time, but are rather incurred year after year, because of the permanent damage caused by increased climate change resulting from the delay," the report states.
Furman told reporters that the estimates are conservative.
The CEA report explores a second way in which delaying action causes economic damages mount. When policymakers eventually do attempt to stave off runaway temperature increases, the most cost-effective options won't be available anymore, the authors say.
"Delays mean that the target will be met in a less efficient manner. We will lose the opportunity to make investments that are consistent with low carbon emissions," Furman said.
Costs of curbing emissions increase by 40 percent for each decade of delay, according to the report, which is based on an analysis of existing studies.
Furman said that uncertainty about the timing, magnitude, and consequences of climate change is not a justification to put off emissions cuts.
Indeed, the report also says cutting emissions is a form of "climate insurance" against the "most severe and irreversible" potential consequences, such as temperature rises on the high end of scientific estimates if emissions continue unchecked.
The report is aimed at bolstering the case for the big EPA rules and other executive steps. On Tuesday the Energy Department is rolling out initiatives to help cut leaks of the potent greenhouse gas methane from natural-gas distribution and transmission lines.
Capitol Hill Democrats are similarly trying to put opponents of curbing emissions on the defensive.
A Senate Budget Committee hearing Tuesday will explore how "failing to mitigate the risks associated with climate change will affect the U.S. federal budget."
At the same time that Democrats are focusing on the financial fallout of climate change, private-sector climate advocates have stepped up their own efforts to stress the economic risks as well.
Last month, an initiative called "Risky Business"—led by former New York City Mayor Michael Bloomberg, former Treasury Secretary Henry Paulson Jr., and billionaire climate activist Tom Steyer—produced an analysis of regional economic vulnerabilities to climate change.
More recently, former Clinton-era Treasury Secretary Robert Rubin, who works with the Bloomberg-Paulson-Steyer group, penned a Washington Post op-ed late last week that calls on federal budget planners to begin reckoning more deeply with global warming.