Seeking relief from urban heat, Toronto has tapped Lake Ontario's frigid depths to cool office buildings, joining a growing number of cities using "deep-source cooling."

Trees bring both comfort and measurable benefits to urban environments. The problem is that roots don't flourish under pavement. Now scientists think they have a solution.

A new study estimates that if the nearly 12,200 animals and plants currently listed as threatened or endangered disappear, another 6,300 "affiliate" species could also be lost.

Musk has been used in perfume and traditional remedies for 5,000 years. But now the deer that secretes the valuable substance is becoming threatened across its range.

Millions of feral cats—domestic animals that have become wild—are said to be running free throughout the U.S., threatening birds and public health.

Vetiver, a grass native to India that grows 13-foot (4-meter) roots, is increasingly used as a low-cost tool to solve problems from soil erosion to pollution.

Manufacturing is virtually nonexistent in the Arctic, yet recent studies show that Eskimos and other Arctic peoples carry unusually high levels of human-made toxins.

In what could be a step toward an affordable source of clean energy, Australian scientists have announced a breakthrough in using sunlight to create hydrogen from water.

An ambitious drug-research project in Madagascar aims to tap the botanical knowledge of traditional healers while helping to protect the country's rain forests.

Catches of dwindling U.S. marine fish stocks by recreational anglers now rival those of commercial fisheries, claims a new report.

To shed light on the sex lives of rosy-finches, North America's highest-breeding birds, researchers clip on crampons and get climbing.

In this TravelWatch column, National Geographic Traveler's geotourism editor examines a stewardship program that keeps Maine's ocean islands untrampled.

Conservationists say the survival of Mongolia's fabled taimen salmon may depend on an unusual ecotourism venture involving Western anglers.

Armed poachers from Sudan have been raiding and destroying neighboring Central African Republic's wildlife resources for years. Now, with the help of a militant U.S. conservationist, the CAR populace is arming and training itself to fight back.

Global warming is threatening travel destinations worldwide. What's more, travelers themselves are contributing to it. Find out what you can do about it.