An economic analysis prepared for the Natural Resources Defense Council (NRDC) and released to influence congressional consideration of greenhouse “cap-and-trade” legislation estimates that “if present trends continue,” total costs of damages from climate change in the U.S. could total as much as 3.6 percent of gross domestic product.

“Four global warming impacts alone – hurricane damage, real estate costs, energy costs, and water costs – will come with a price tag of 1.8 percent of U.S. GDP, or almost $1.9 trillion annually (in today’s dollars) by 2100, according to the study, “What We’ll Pay if Global Warming Continues Unchecked.”

For reporters and editors looking for ways to localize the climate change impacts story, the report includes an interesting city-by-city comparison. For instance, it says increased average temperatures of 13 degrees in 2100 will make Boston “feel like” Memphis, and Minneapolis feel like San Francisco. Other pairs provided as examples: Portland and Philadelphia\Las Vegas; Kansas City, Mo., and Washington, D.C.\Houston; San Francisco and Baltimore\New Orleans; Phoenix\Bangkok, Thailand; Miami\no comparable city.

“It is difficult to put a price tag on many of the costs of climate change: loss of human lives and health, species extinction, loss of unique ecosystems, increased social conflict, and other impacts extend far beyond any monetary measure,” says the report, whose principal authors are Frank Ackerman and Elizabeth A. Stanton, of Tufts University.