Lauren Summer

It's the annual spring migration.

Almost 250 million birds are traveling across the U.S.

right now.

Most birds migrate at night, and some are on journeys that take them from South America all the way to the Arctic.

Artificial lights, like from buildings, can interfere with their navigation.

So conservation groups are asking residents to turn out or dim non-essential lights overnight for the next few weeks.

The biggest hotspots are in the South, Midwest, and Mid-Atlantic states, as well as the West Coast.

Lauren Summer, NPR News.

Zeldin spoke at a conference of the Heartland Institute, a free market group that denies that humans are contributing to climate change.

Scientific research shows that burning fossil fuels has increased carbon dioxide in the atmosphere to the highest level in human history.

That traps heat, raising temperatures and making weather events like hurricanes more extreme.

Zeldin celebrated the EPA's decision to stop regulating carbon dioxide as a pollutant.

He says that policy was government overreach and focused too much on the worst-case scenarios.

Lauren Summer, NPR News.

Fourteen states experienced their warmest or second warmest winter in 131 years of record-keeping.

That's according to a new assessment by the National Oceanic and Atmospheric Administration.

One-third of the U.S.

population experienced the warmest winter daytime highs on record.

That trend was mostly across the Great Plains and western U.S.

High temperatures have led to a low snowpack there, which could have impacts this summer.