"At the foot of a giant sequoia in California's Sierra Nevada, two arborists stepped into harnesses then inched up ropes more than 20 stories into the dizzying canopy of a tree that survived thousands of years, enduring drought, wildfire and disease. There, the arborists clipped off tips of young branches to be hand-delivered across the country, cloned in a lab and eventually planted in a forest in some other part of the world."

"A month after hackers blacked out power in western Ukraine, a team of U.S. security experts touched down in Kiev to piece together the extraordinary assault."

"Exposure to more intense shale gas development correlates with a higher risk of asthma attacks among asthma patients, according to a new study of Pennsylvania's Marcellus Shale, one of the nation's largest and most active fracking regions."

"The enormous algae outbreak that has coated swaths of Florida's St. Lucie River with guacamole-like sludge is a man-made affliction, arising from political and economic decisions made over the past 140 years."

"The Tennessee Valley Authority's Colbert and Widows Creek power plants have already burned their last piece of coal to generate electricity, but some environmentalists are worried that the tons of coal ash left behind in watery ponds could cause environmental problems long after the burners were turned off."

"Matt Mead, the governor of Wyoming, the nation’s leading coal-producing state, fiercely opposes President Obama’s climate change regulations, which could shutter hundreds of coal plants and deeply wound his state, one of 27 that are suing to block the plan. Nevertheless, Mr. Mead, a Republican, has ordered his top environmental officials to prepare to comply with the president’s effort... ."

"Earth's persistent record 2016 heat is now dancing near levels that a world agreement is trying to avoid, federal scientists said."

"A federal appeals court [Tuesday] upheld U.S. EPA's retroactive veto of a water permit for a West Virginia mining project in a big win for the Obama administration."