1. A road map for change.

A major scientific report on climate issued by 13 federal agencies over the holiday weekend says the U.S. will have to spend billions to protect against the effects of global warming.

In direct language, the 1,656-page assessment lays out the devastating effects of climate change on the U.S. economy, health and environment, including record wildfires in California, crop failures in the Midwest and crumbling infrastructure in the South. Above, an oil refinery in Norco, La.

Our climate reporter breaks down five ways scientists say the U.S. must adapt to protect coastlines, rebuild sewers and overhaul farming.