Just warming up

Twenty-five years after he opened the climate-change debate by warning Congress that fossil fuel emissions would cause runaway global warming—and 15 years after the Earth stopped warming substantially—controversial climatologist James Hansen has retired. The “grandfather of global warming” left his 46-year career at NASA in early April, but not to pursue solitude and silence: Hansen, 72, will use retirement to raise environmental alarm full-time.

“As a government employee, you can’t testify against the government,” he told The New York Times, explaining plans to participate in lawsuits against state and federal regulators who allegedly haven’t done enough to battle global warming. The retired scientist will join younger environmentalists in protesting projects like the Keystone XL pipeline, which would transport oil from Canadian tar sands. He has already been arrested several times since 2009 during protests against the pipeline (most recently in February) and against mountaintop coal mining.

Much of Hansen’s research in the 1970s focused on Venus, but by the 1980s he was writing papers with titles like “Climate trends due to increasing greenhouse gases.”

“It is time to stop waffling so much and say that the evidence is pretty strong that the greenhouse effect is here,” he told reporters in 1988.

In the years afterward, Hansen’s warnings of catastrophic climate change grew louder, his patience with skeptics thinner: In 2005 he complained the George W. Bush administration was trying to muzzle him, and in 2008 said oil executives should be tried for “high crimes against humanity and nature.” Later he wrote that burning oil reserves and tar sands could cause Earth to become as hot and desolate as Venus, his old planetary interest. Even colleagues who share his views on warming think Hansen sometimes takes them a bit far. And that was before retirement.

Stinging decline

Honeybee deaths have reduced some U.S. beekeepers’ stocks by 50 percent or more this year, and European and U.S. farmers are increasingly worried. A quarter of the American diet relies on honeybee pollination, but since 2006, the mysterious illness known as colony collapse disorder has wiped out up to a third of hives annually. Although experts blame the deaths on a combination of pesticides, mites, viruses, bacteria, and stress, some beekeepers point to a group of pesticides called neonicotinoids.

Several European nations have already banned the “neonics,” even though manufacturers defend them as safe, and a March study failed to link them to bee declines. The U.S. Environmental Protection Agency is reviewing their safety. Meanwhile, honeybee scarcity has driven up the cost of U.S. hives, and could in turn raise the price of crops honeybees pollinate, such as apples, almonds, and green beans. —D.J.D

The smallest losers

Patients who undergo gastric bypass weight loss surgery may need to thank gut bacteria, at least in part, for their shed pounds. Researchers concluded in Science Translational Medicine that one-fifth of the weight loss after gastric bypass seems to result from changes in the types of digestive bacteria inhabiting the intestines. By rearranging how food passes from the stomach to the intestines, the surgery alters the makeup of bacteria colonies, although it’s not yet clear how they affect weight. The findings could lead to surgery-free, bacteria-based weight loss treatments. —D.J.D.