People in a pedal-powered boat take advantage of a breeze creating cooling spray from fountains in Echo Park Lake near downtown Los Angeles Thursday, July 6, 2017. A heat wave blanketing the U.S. Southwest has toppled temperature records, raised wildfire danger and sent residents to pools, beaches and even fountains for cool relief. Officials warned people to avoid strenuous activity during the day on Friday, when the worst heat was expected across Southern California. (AP Photo/Reed Saxon)
FILE - In this July 17, 2012, file photo, adult female walruses rest on an ice flow with young walruses in the Eastern Chukchi Sea, Alaska. If walrus is in your dinner plans, the Centers for Disease Control and Prevention recommends you make sure it's well done. The federal health agency warned of the effects of undercooked game meat after two outbreaks of trichinosis over the last year in western Alaska. The outbreaks sickened 10 people and all have fully recovered. (S.A. Sonsthagen/U.S. Geological Survey via AP, File)
The Longview Power Plant in Maidsville, W.Va.,Thursday, July 6, 2017. Operators of the coal-burning plant, a new plant that began producing power in 2011, report higher efficiency and lower emissions than other U.S. coal-fired power plants. (AP Photo/Michael Virtanen)
Energy Secretary Rick Perry, left, and Sen. Shelley Moore Capito, R-W.Va., talk with the operators inside the coal-burning Longview Power Plant in Maidsville, W.Va., Thursday, July 6, 2017. (AP Photo/Michael Virtanen)
Energy Secretary Rick Perry, right, talks with Sen. Joe Manchin, D-W.Va., left, and Sen. Shelley Moore Capito, R-W.Va. outside the coal-burning Longview Power Plant in Maidsville, W.Va., Thursday, July 6, 2017. (AP Photo/Michael Virtanen)
FILE - In this April 17, 2014, file photo, backhoes excavate in a hole reserved for a rail tunnel, left, during the early days of construction at the Hudson Yards redevelopment site on Manhattan's west side in New York. A concrete box was planned inside the project to preserve space for a tunnel from Newark to New York City that would allow it to double rail capacity across the Hudson River. An environmental study has been released for the Hudson River rail tunnel project, amid concerns the effort could lose key federal funding under President Donald Trump's proposed budget. (AP Photo/Bebeto Matthews, File)
FILE - This July 6, 2011, file photo shows a grizzly bear roaming near Beaver Lake in Yellowstone National Park, Wyo. Native American tribes, clans and spiritual leaders from six states and Canada say the U.S. government's decision to lift protections for grizzly bears in the Yellowstone National Park area violates their religious freedom. (AP Photo/Jim Urquhart, File)
FILE - In this Sept. 25, 2013, file photo, a grizzly bear cub searches for fallen fruit beneath an apple tree a few miles from the north entrance to Yellowstone National Park in Gardiner, Mont. Native American tribes, clans and spiritual leaders from six states and Canada say the U.S. government's decision to lift protections for grizzly bears in the Yellowstone National Park area violates their religious freedom. (Alan Rogers/The Casper Star-Tribune via AP)
Liquor bottles that rattled off the shelves after an earthquake sit on the floor at a liquor store Thursday, July 6, 2017, in Lincoln, Mont. The strongest earthquake to hit Montana in more than half a century sent bartenders jumping over bars, food falling off grocery store shelves and awakened residents and dogs more than 30 miles from its epicenter. (Thom Bridge/Independent Record via AP)
FILE - In this June 13, 2017, file photo, California Gov. Jerry Brown discusses climate change at a news conference in Sacramento, Calif. Gov. Brown plans to convene a Global Climate Action Summit next year in his latest action to position the state as a leader in battling global warming as the White House recedes. (AP Photo/Rich Pedroncelli, File)
Yellow tape warns drivers of a large tree branch felled by an earthquake that is partially blocking a road in Helena, Montana, on Thursday, July 6, 2017. The 5.8-magnitude quake and numerous aftershocks were centered about 30 miles away in Lincoln, Montana, and could be felt as far away as Washington state. (AP Photo/Matt Volz)
A tree was snapped in half by a 5.8-magnitude earthquake felt in Helena, Montana, on Thursday, July 06, 2017. The quake and numerous aftershocks were centered about 30 miles away in Lincoln, Montana, and could be felt as far away as Washington state. (AP Photo/Matt Volz)
South Houston volunteer firefighter Robert Kyle moves a hose to douses hot spots remaining from a two-alarm fire that destroyed a two-story warehouse on North 1st Street near Spencer Highway Thursday, July 6, 2017, in South Houston. The flames from the fire blew out a transformer, leaving people in the area without power. (Godofredo A. Vasquez/Houston Chronicle via AP)
South Houston volunteer firefighter Robert Kyle douses hot spots remaining from a two-alarm fire that destroyed a two-story warehouse on North 1st Street near Spencer Highway Thursday, July 6, 2017, in South Houston. The flames from the fire blew out a transformer, leaving people in the area without power. (Godofredo A. Vasquez/Houston Chronicle via AP)
Houses and a road are seen submerged in muddy water after a huge landslide caused by heavy rain hit the Ono district in Hita, Oita prefecture, southwestern Japan Thursday, July 6, 2017. Troops worked Thursday to rescue hundreds of people stranded by flooding in southern Japan. (Nozomu Endo/Kyodo News via AP)
U.S President Donald Trump speaks during the Three Seas Initiative transatlantic roundtable in the Great Assembly Hall of the Royal Castle, in Warsaw, Thursday July 6, 2017. The Three Seas Initiative is an alliance among a dozen eastern and central European nations that are bordered by the Adriatic, Baltic and Black seas. The group aims to reduce their dependence on oil and gas supplied by Russia. (AP Photo/Evan Vucci)
FILE - In this July 24, 2016, file photo, coal brought from Siberia are be seen awaiting loading onto a ship bound for China in the North Korean special economic zone of Rason. Despite U.S. President Donald Trump's hopes for China's help in dealing with North Korea and his recent tough talk on the matter, the two sides seem to be growing further apart as their approaches and concerns diverge. China shows no sign of caving in to U.S. pressure to tighten the screws on North Korea, while the North's recent missile tests have done little to rattle Beijing. China's bottom line continues to hold: no to any measures that might topple Kim Jong Un's hard-line communist regime. (AP Photo/Eric Talmadge, File)
In this image provided by CERN, a worker puts in the final touches on the collider equipment in this 2007 photo. Scientists at the Large Hadron Collider in Europe have discovered a new subatomic particle. It’s a long theorized but never-before-seen type of baryon. Baryons are subatomic particles made up of quarks. This particle is the first of its kind two have two heavy quarks, both a type called “charm.” It was discovered during collisions in the LHCb experiment.(CERN/European Organization for Nuclear Research via AP)
In this image provided by CERN, shows a artists conception of a new subatomic particle. Scientists at the Large Hadron Collider in Europe have discovered a new subatomic particle. It’s a long theorized but never-before-seen type of baryon. Baryons are subatomic particles made up of quarks. This particle is the first of its kind two have two heavy quarks, both a type called “charm.” (CERN via AP)