Beijing issued its first air pollution red alert for 2016 Thursday, as choking smog is expected to cover the city and surrounding areas in north China during the next five days.

From 8 pm on Friday, half of Beijing's private cars will be ordered off the road, with an odd-even number plate system in force, according to a notice posted on the official website of the Beijing municipal government.

Environmentalists have hit out at organizers of the Miss Universe beauty pageant in the Philippines, calling them "irresponsible" for letting contestants swim with endangered whale sharks.

Animal rights defenders stripped down Sunday in the Spanish tourist hub of Barcelona to draw attention to the cruelty of the fur industry.

A pair of jetlagged sea otters arrived in France on Friday after a 9,000-kilometer (5,600-mile) flight from Alaska to their new home at a sea life park.

Leonardo DiCaprio met President-elect Donald Trump to discuss climate change and how renewable, clean energy could boost the economy by creating millions of new jobs, the actor's foundation said Thursday.

Terry Tamminen, chief executive of the Leonardo DiCaprio Foundation, said in a statement he and the Hollywood star presented the Republican property tycoon, his daughter Ivanka and other aides with a plan to unleash "a major economic revival" through investments in sustainable infrastructure. 

President-elect Donald Trump announced on Thursday he had tapped Oklahoma Attorney General Scott Pruitt, criticized as a climate change denier and a staunch fossil fuel ally, to head the Environmental Protection Agency.

"For too long, the Environmental Protection Agency has spent taxpayer dollars on an out-of-control anti-energy agenda that has destroyed millions of jobs, while also undermining our incredible farmers and many other businesses and industries at every turn," Trump said in a statement.

Polar bear numbers could drop a third by mid-century, according to the first systematic assessment, released Wednesday, of how dwindling Arctic sea ice affects the world's largest bear.

The U.S. Army Corps of Engineers on Sunday nixed plans for a controversial oil pipeline crossing in North Dakota, a major victory for Native Americans and environmentalists who had staged months of protests.

The pipeline had been set to cross under the Missouri River and man-made Lake Oahe, which are drinking water sources for the Standing Rock Sioux Tribe.

The heavyweights of world trade, including the United States, China and Japan, meet in Geneva this weekend to establish a list of environmentally friendly products for which tariffs can be eliminated or reduced.

The world's big cities will need $375 billion of investment to curb climate change, a large gathering of mayors heard in Mexico on Thursday.

"It is a lot, but there is no other option. Together we will seek that money," said the new president of the C40 network of big cities, Paris Mayor Anne Hidalgo.