New research deals a blow to the hypothesis that a decrease in atmospheric oxygen contributed to a mass extinction 250 million years ago.

Researchers are using cinnamon’s microbe killing properties to develop an anti-mold wrapper.

Rush-hour traffic on Interstate 405 in Los Angeles. A bill in the California Legislature would promote housing patterns intended to slow the increase in emissions of heat-trapping gases.

Biologists at Harvard have converted cells from a mouse’s pancreas into the insulin-producing cells that are destroyed in diabetes.

An appeals committee at Purdue University has upheld findings of misconduct by Rusi P. Taleyarkhan.

A polar bear seen in waters off the Alaska coast this month. Some have swum north, apparently trying to reach the polar ice.

The New York attorney general announced an agreement that would require Xcel Energy, a builder of coal-fired plants, to disclose to investors the financial risks of global warming.

The roof of a Con Edison training center in Long Island City is covered with sedum, an absorbent plant typically found in deserts.

The government announced it would expand a national park on the island of Sumatra, which hosts endangered elephants and tigers.

From left, three views of a fragment of one of the Dead Sea Scrolls: a plain digital image, a color scan and an infrared scan.

The Maple Ridge Wind farm near Lowville, N.Y. It has been forced to shut down when regional electric lines become congested.

In Santa Barbara County, where an oil spill devastated the coastline in 1969, the opposition against offshore drilling may be softening.

Lauren Yarmuth, a green consultant, helps architects like Guy Geier.

I KNOW YOU John M. Marzluff, a wildlife biologist tested crows’ ability to distinguish between faces.

GOING GREEN A destructive citrus disease obstructs nutrients in trees. Fruit stays green and is lopsided and bitter.

HAZARD What is thought to be a fault runs near the Indian Point nuclear plant, 24 miles north of the city.

Becka Warren, who writes for grist.org from Vermont, drafts most of Umbra's columns.

A New Jersey company will announce a plan to use wind turbines to produce compressed air that can be stored underground or in tanks and released later to power generators during peak hours.

The Environmental Protection Agency has agreed to develop a plan that could lead to Newtown Creek’s being named a federal Superfund site.

Tails of three right whales earlier this year in Cape Cod Bay, near Provincetown, Mass.

Twelve states are suing the Environmental Protection Agency for violating the federal Clean Air Act by refusing to control greenhouse gas emissions at oil refineries.

Some salmonella bacteria are able to invade the intestinal walls.

The network of filaments stretching out from galaxy NGC 1275.

SEAWORTHY Workers at Ladish Forging drove a press onto hot titanium, transforming it into a cup, part of the personnel sphere for the submersible.

FUTURIST Vernor Vinge, a computer scientist and science fiction writer, at the Geisel Library in San Diego.