EPA last week released Climate Change in the United States: Benefits of Global Action. As summarized by the agency’s press release, the 96-page report “compares two future scenarios”:
a future with significant global action on climate change, where global warming [in 2100] has been limited to 2 degrees Celsius (3.6 degrees Fahrenheit), and a future with no action on climate change (where global temperatures rise 9 degrees Fahrenheit). The report then quantifies the differences in health, infrastructure and ecosystem impacts under the two scenarios, producing estimates of the costs of inaction and the benefits of reducing global GHG emissions.
The report has five main sections (health, infrastructure, electricity, water resources, agricultural and forestry, and ecosystems). At the end of each section, EPA cites to an underlying technical study. I may examine one or more of those in a later post. Here I will point out a few tricks EPA uses to make its case.
The core bias that predetermines all the alarming forecasts in EPA’s report is the assumption that, in the reference (“no action”) scenario, global temperatures will increase by 9°F (5°C) between 2010 and 2100 (the red line in the chart below).
Average U.S. temperatures are projected to rise even higher. In the reference scenario, EPA projects a 14ºF increase above present temperatures in the Mountain West and a 12°F increase in the northern regions. In contrast, temperatures rise no more than 4ºF in any state under the “global action” scenario.
Unsurprisingly, in EPA’s assessment, unmitigated warming produces terrible and terrifying climate impacts whereas “global action” reduces such impacts to manageable and non-threatening levels. For example, EPA claims significant global action would reduce U.S. urban heat-related mortality by 93% in 2100, saving approximately 12,000 lives in that year.
How reasonable is it, though, to suppose that average global temperatures in 2100 will be 9°F higher than they are today? Not very. [click to continue…]