Bloomberg: The cost to the U.S. of doing nothing to curb global warming would reach $3.8 trillion a year by the century’s end, a new study says. Failing to address climate changes triggered by the burning of fossil fuels such as oil and coal would cost the U.S. economy more than 3.6 percent of gross domestic product, according to the report by researchers at Tufts University for the Natural Resources Defense Council, an environmental advocacy group. The financial fallout of climate change — whether from …