U.S. Climate Warming

The U.S. is already seeing the effects of climate change, including larger and more frequent forest fires in western states, says a government report released last week. Climate change now affects water resources, agriculture, land, and biodiversity, says the report from the U.S. Climate Change Science Program, which integrates global warming research from 13 federal agencies. Drought conditions are increasing in the West and Southwest, the report finds, while mountain snowpacks in the West are shrinking overall and snow is melting earlier in the spring. In the past 19 years, the growing season in temperate areas has increased by 10–14 days, the report says. Meanwhile, plant and animal species are migrating because of climate change, altering the composition of ecosystems. The report also predicts that in coming years, grains and oilseeds will mature more rapidly due to increased temperatures and rising atmospheric levels of carbon dioxide, but rising temperatures will increase the likelihood of crop failures due to heat waves or drought. Recent research also suggests that glyphosate, the most widely used herbicide in the U.S., loses its ability to control weeds grown at increased atmospheric levels of CO₂, the report says.