- News Home
5 December 2013 11:26 am ,
Vol. 342 ,
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
- 5 December 2013 11:26 am , Vol. 342 , #6163
- About Us
Too Bright Future for Global Climate?
25 September 1997 8:00 pm
The sun may be getting brighter, according to a report in tomorrow's Science*. If the controversial analysis is correct--and if the change signals a long-term trend--a brightening sun could be a major player in climate change.
In the debate over whether greenhouse warming has arrived and just how bad it will get, the sun has been a relatively minor factor. But even a tiny dimming of the sun--the climate system's sole energy source--could greatly slow any warming due to greenhouse gases, while a slight brightening could worsen what might already be a bad situation. Unfortunately, the longest-running direct observations of the sun have been too short to say whether its brightness actually varies over the decades as needed to influence climate.
By splicing together separate records from satellites that together have monitored the sun since 1978, atmospheric physicist Richard Willson from Columbia University's Center for Climate Systems Research in Altadena, California, has constructed a record long enough to reveal a striking trend: a brightening of 0.036% per decade from 1986 to 1996. That brightening, if sustained for 100 years, might produce a warming of about 0.4 degrees Celsius, says Willson. The current best estimate for greenhouse warming at the end of the next century is 2.0 degrees C.
But the reliability of one of the records leaves much room for debate. Willson had to tie together the records of two identical satellite monitors, one that stopped operating in 1989 and a second that was not launched until 1991, with a record from a third, less capable instrument. Still, Willson's analysis "seems quite reasonable," says Lee Kyle of NASA's Goddard Space Flight Center in Greenbelt, Maryland, whose instrument provided the linking data set. "I think Willson is correct in saying the best evidence shows an increase. How strong that evidence is, is another matter." Others say the measurements aren't good enough to support any conclusions yet. "I think we are not able to do it at this point," says Claus Frohlich of the World Radiation Center in Davos, Switzerland. "We just don't know."