"Cities in six continents joined up to form the world's largest alliance to combat climate change on Wednesday, a move intended to help making ground-level changes to slow global warming."

"Firefighters across Arizona and New Mexico battled 31 wildfires on Wednesday, their efforts complicated by a relentless heat wave and bone-dry conditions. And in the Angeles National Forest, on the northern edge of Los Angeles, two fires kept more than 300 families from their homes as the fires threatened to merge into one."

"Surging wildfires on Tuesday forced new evacuations of hundreds of homes across the West, while firefighters began beating back a pair of big adjacent blazes looming over suburban Los Angeles."

"In northernmost Alaska, permafrost is steadily warming and large amounts of thaw are expected by the end of the century. But for some spots, the thaw is about 70 years ahead of that predicted pace, new research shows."

"At night, just after the full moon, teams of scientists dive beneath the waves to study one of the planet’s most prolific and mysterious rites of reproduction."

"Wildfire warnings were posted across parts of three Western U.S. states on Sunday as a heat wave baked the region in record, triple-digit temperatures, stoking flames in California from the coastal foothills outside Santa Barbara to desert brush near the Mexican border."

"YOSEMITE NATIONAL PARK -- President Barack Obama mixed business with pleasure here Saturday, touting the importance of national parks and then seeing one up close for himself as he took in the sights at what is arguably the crown jewel of the national park system."

"When beavers build dams, they create reservoirs that store water and replenish groundwater supplies."

"The company asks a federal court in Texas to block the investigation by Massachusetts prosecutors, citing its constitutional rights."

"One of the world’s largest coal companies, Peabody Energy, paid a prominent scientist and dozens of others to promote climate change denial, new documents reveal."