REPORT: The Cost of Ignoring Climate Change Is $20 Trillion A Year

globalwarming511.jpg Global warming deniers frequently fall back on the following argument: even if global warming is real, it’s too expensive to mitigate. For example, the National Review’s Jason Steorts said it would require “economic castration.” Such arguments, however, ignore the costs of inaction.

A new study by the Global Development and Environment Institute at Tufts University reveals the severe economic consequences of doing nothing. From the report:

[I]f nothing is done to restrain greenhouse gas emissions, annual economic damages could reach US$20 trillion by 2100 (expressed in U.S. dollars at 2002 prices), or 6 to 8 percent of global economic output at that time (Kemfert 2005). The same study found that immediate adoption of active climate protection policies could limit the temperature increase to 2° and eliminate more than half of the damages…If, however, climate protection efforts do not begin until 2025, the same model estimates that it will be impossible to limit warming to 2° by 2100 — and climate protection in general will be more expensive, the later it starts.

Even that estimate “necessarily omit[s] some of the most troubling potential consequences of climate change.” Importantly, the study found that the cost of mitigation is about one quarter the cost of doing nothing.