People in funny costumes race down the slope in bathtubs during the 7th Bathtub race at Stoos, Switzerland, on January 19, 2019. (Photo by Urs Flueeler/EPA/EFE/Rex Features/Shutterstock)

A man stands near smoke billowing from a brick kiln in Karachi, Pakistan, 14 December 2018. According to the UN report, carbon dioxide (CO2) emissions have increased for the first time in four years. The United Nations Conference COP24, held in Katowice, Poland, until 14 December 2018, searches for a common position in the fight against climate change. (Photo by Shahzaib Akber/EPA/EFE)

A section of multi-vehicle accident on Interstate 75 is shown in Detroit, Thursday, January 31, 2013. Snow squalls and slippery roads led to a series of accidents that left at least three people dead and 20 injured on a mile-long stretch of southbound I-75. More than two dozen vehicles, including tractor-trailers, were involved in the pileups. (Photo by Paul Sancya/AP Photo)

Storm clouds blanket the sky over Great American Ball Park as Starlin Castro #13 of the Chicago Cubs fields a ground ball in the fifth inning against the Cincinnati Reds as on July 7, 2014 in Cincinnati, Ohio. (Photo by Jamie Sabau/Getty Images)

Visitors look at penguins wearing Santa Claus (in red) and Christmas tree (in green) costumes during a promotional event for Christmas at an amusement park in Yongin, south of Seoul, December 18, 2013. (Photo by Kim Hong-Ji/Reuters)

Among the fish populations that could be harmed by the Xayaburi dam in Laos is the critically endangered Mekong giant catfish, considered by the Guinness Book of World Records to be the world’s largest freshwater fish. The fish, which grows to 650 pounds and about 10 feet long, is only found in the Mekong River. It is migratory, moving between downstream habitats in Cambodia upstream to northern Thailand and Laos each year to spawn. Some experts fear the Xayaburi dam could block the migration and drive the giant catfish to extinction. (Photo by Courtesy of Zeb Hogan/University of Nevada, Reno)

Four-year-old Solaris Arias (right) jumps through water spraying from an open fire hydrant in Providence, Rhode Island, on June 20, 2012. Much of the state remained under a heat advisory Tuesday afternoon because of the steamy air mass that has moved into the region resulting in temperatures in the 90s. (Photo by Steven Senne/AP Photo)

In this June 17, 2014 photo, a North Korean man takes shelter in the rain next to long propaganda billboards in the town of Samjiyon in North Korea's Ryanggang province. The Associated Press was granted to embark on a weeklong road trip across North Korea to the country’s spiritual summit Mount Paektu. The trip was on North Korea's terms. An AP reporter and photographer couldn't interview ordinary people or wander off course, and government “minders” accompanied them the entire way. (Photo by David Guttenfelder/AP Photo)