Earth

Earth

Ancient tree rings reveal past climate

Using tree-ring analysis, an international team of researchers has reconstructed the earliest record of annual climate variation.

Earth

POPs in the butter

Governments may be able to monitor trends in the release and transport of persistent organic pollutants by sampling butter.

Earth

Leaden calcium supplements

Consuming calcium along with lead limits, and may prevent, the body's absorption of the toxicant.

Earth

Thick ice scraped rock bottom in Arctic

Scuffs, scrapes, and gouges found atop undersea plateaus and ridges in the Arctic Ocean suggest that kilometer-thick ice shelves covered much of the ocean there during some previous ice ages.

Earth

A quick recovery after dinosaur deaths

Evidence from 65-million-year-old sediments suggests that a single impact from space wiped out the dinosaurs and that ecosystems recovered from the trauma in only a few thousand years.

Earth

New analysis rejuvenates Himalayas

The Asian mountain range that includes some of the tallest peaks in the world turns out to be about 15 million years younger than geologists previously thought.

Earth

Diesels: NO rises with altitude

The combustion chemistry of heavy-duty diesel trucks changes with altitude.

Earth

Passive smoking’s carcinogenic traces

Researchers isolated markers of a cigarette-generated carcinogen in urine of nonsmoking women married to smokers.

Earth

Satellites verify greenhouse-gas effects

Comparisons of data obtained from instruments that orbited Earth more than 25 years apart provide direct evidence that the planet's greenhouse effect increased significantly between 1970 and 1997.

Earth

Is there a vent in the global greenhouse?

Satellite observations of ocean temperatures in tropical regions of the western Pacific suggest that when ocean temperatures there warm up, the amount of heat-trapping cirrus clouds decreases, possibly providing a heat-venting effect that could help reduce global warming.

Earth

A Nation Aflame

In the wake of one of the worst fire seasons in the past 50 years, scientists are assessing risk as more people move into fire-prone areas and developing ways to better predict the behavior of--and the potential for--wildfires.

Earth

Siberian snow has long-range effects

The strength of the winter weather feature called the Siberian high is linked to the amount of early-season snow cover in its namesake region.