"Last week, the Department of Energy announced a little-noticed update to its energy-efficiency standards for microwaves, requiring newer models to use less power in stand-by mode," reports Plumer. "But there was a surprise buried in the fine print: The agency is now using a higher figure for the 'social cost of carbon' in calculating the benefits of the rule. Instead of assuming that the harm caused by carbon-dioxide emissions comes to $22 per ton in 2013, regulators are now using a figure [PDF] of about $36 per ton."
"That’s a big shift — the Obama administration is effectively saying that climate change will be more damaging than previously estimated, in part because of the impacts of future sea-level rise," Plumer explains. "And that means U.S. government agencies could, in theory, justify even stricter regulations to curb greenhouse-gas emissions."
"This might sound like nitpicking. But seeing as how much of the Obama administration’s climate-change agenda will likely be carried out through the Environmental Protection Agency, this small tweak could make a big difference in the years ahead."