Could Sun-Protective Clothing Replace Sunscreen?
Dear EarthTalk: Is there really such a thing as “sun-protective clothing?” If so, does it mean I can dispense with oily sunscreens once and for all? -- John Sugarman, San Diego, CA [More] Presented By:You Need the Speed of Norton 2009Introducing the revolutionary Norton Internet Security 2009. With a one-click, one-minute install, under 7MB of memory usage and fewer, shorter scans, it?s the fastest security suite anywhere. Get your FREE trial today!Click to Learn More www.norton.com/speed Ads by Pheedo rss.sciam.com |
The Arctic Thaw Could Make Global Warming Worse
A young scientist with curly, reddish hair tucked beneath a knit cap stepped gingerly onto the three-day-old ice of a remote lake in northeastern Siberia. Coating the black depths like cellophane, the thin film held no promise to bear her weight, but a sudden dunk in the frigid water was a risk she had to take. Searching the lake by rickety rowboat all summer had failed, and any day winter’s first big snow would engulf the region, obscuring the lake’s surface until spring. She could not afford to wait that long.The woman shivered in her worn, blue down jacket and glanced up at the overcast sky. After one more cautious step, she spotted her quarry: a cluster of platter-size bubbles frozen into the ice. Those pockets of gas, which had risen from thawing permafrost--formerly frozen soil--at the lake’s bottom, were the aim of her doctoral research. Long elusive, they suddenly stood out like white stars against a night sky, though less serenely. With a small pick she cracked the icy skin of one of the bubbles and remained unfazed when it hissed back like a punctured gas pipe. Leaning forward, she apprehensively struck a match just above the broken bubble and flames as high as her head burst skyward. The flammable substance was methane, a greenhouse gas that could cause more global warming than carbon dioxide (CO2). [More] rss.sciam.com |
Shipwreck damages pristine coral reef via destructive organism
Nestled within the new Pacific Remote Islands Marine Monument lies Palmyra Atoll, one of the last pristine coral reefs left on the planet some 960 nautical miles south of Hawaii. Or near pristine. In 1991 a 100-foot longline fishing ship--the "Hui Feng No. 1"--foundered on the reef under mysterious circumstances. In the wake of that shipwreck, a destructive species of corallimorpharian--a kind of half-coral, half-anemone sea creature--began to take over the reef. [More] rss.sciam.com |
Uncharted waters: Hydrogen and the "law of unintended consequences"
Editor's Note: A team of Rensselaer Polytechnic Institute students are traveling up New York's Hudson River this week on the New Clermont , a 6.7-meter boat outfitted with a pair of 2.2-kilowatt hydrogen fuel cells to power the boat's motor. Their journey began September 21 from Manhattan's Pier 84 and will cover 240 kilometers (at a projected speed of 8 kilometers per hour). After making several stops along the way, the crew expects to arrive back at Rensselaer Polytech's campus in Troy, N.Y., on September 25. This is the third of Scientific American.com's blogs chronicling this expedition, called the New Clermont Project. [More] rss.sciam.com |
Setting Boundaries: 10 Guidelines to Save Earth
Editor's note: The original online version of this story was posted on September 23, 2009. The scale of humanity’s impact on the globe is becoming ever more apparent: we have wiped out species at a rate to rival great extinction events of all geologic time as well as contributing to a rapidly acidifying ocean, dwindling ice caps and even sinking river deltas. Now an international group of 29 scientists has taken a preliminary stab at setting some concrete environmental thresholds for the planet. [More] rss.sciam.com |