Two Republican governors last week urged Energy Secretary Rick Perry to “maintain the [U.S.] commitment to the Paris Agreement.” In a joint letter to Perry dated 17th May, Gov. Philip Scott of Vermont and Gov. Charles Baker of Massachusetts pledge they will “continue to do our share” to reach President Obama’s goal of reducing U.S. emissions 26 to 28 percent below 2005 levels by 2025.
It’s not clear what the Governors think their letter will accomplish. Perry joined the “Remain” camp in the Trump administration nearly a month ago. However, he favors staying in the Agreement only if Trump replaces Obama’s emission-reduction pledge—the U.S. “nationally determined contribution” (NDC)—with a “commitment” consistent with Trump’s pro-growth energy agenda.
The Governors decry the “impacts of rising sea levels, increasingly severe flooding, heat waves, droughts, and decline in snow cover,” so maybe they believe their efforts to implement Obama’s NDC will protect their states from such impacts. If so, they are mistaken.
Even if all nations fulfill every promise in their NDCs by 2030, which is unlikely, “the total temperature reduction will be 0.048°C (0.086°F) by 2100,” according to a peer-reviewed study by environmental researcher Bjorn Lomborg. That change is less than the current margin of error (0.08°C) in estimates of annual average global temperature. The cooling influence of all combined Paris Agreement NDCs during the policy-relevant future would be smaller still. Clearly, implementing Obama’s NDC nationwide would make no measurable or practical difference in snow cover and the like over the next quarter century. The contributions of Vermont and Massachusetts would be even less consequential.
Besides, contrary to what the governors suggest, there is as yet no clear evidence of accelerating sea level rise since 1993; U.S. heat-related mortality has declined, decade by decade, since the 1960s; U.S. floods have not increased in frequency or intensity since 1950; and U.S. flood damage as a percentage of GDP has declined by about 75 percent since 1940.
The governors do not say where they get their snow cover data. Using Rutgers University Global Snow Lab data, I plot the monthly snow cover for North America (Canada + USA) from November 1966 through April 2017 (see below). There is essentially no trend in winter month snow cover area and perhaps a slight increase in summer month snow cover.
For what it’s worth, Burlington, Vermont’s annual snowfall in 2016-2017 was 100.4 inches—about 38 percent above the long-term (1892-2017) average. Since 2000, Burlington’s annual snowfall has been almost 20 percent above the long-term average. Boston had record breaking snowfall in 2014-2015, and long-term records going back to 1895 show a slight upward trend.
So, if the Governors’ stated reasons don’t explain their support for the Paris Agreement, what does? Perhaps cheap environmental virtue combined with a belief that the Agreement will transfer wealth from Midwest states to Northeast states.
The Clean Power Plan (CPP) is the centerpiece of Obama’s NDC, and Vermont was the only state in the Union not included in the CPP because it has no fossil-fuel power plants. As for Massachusetts, its CPP goal is a 3 percent increase relative to its baseline projection. For perspective, 21 states with substantial fossil fuel assets have to cut their emissions 20 to 40 percent below baseline.