csmonitor.com - The Christian Science Monitor Online
 
john overmyer

Are sunspots prime suspects in global warming?

Climate-change 'optimists' say complex natural cycles may be at the heart of global warming.

Page 1 of 4

It's a modern-day climate scuffle William Herschel would recognize. He should. He helped trigger it.

In 1801, the eminent British astron­­omer reported that when sunspots dotted the sun's surface, grain prices fell. When sunspots waned, prices rose.

He suggested that shifts in grain prices were a stand-in for shifts in climate. Large numbers of sunspots led to a warmer sun, he reasoned. With more warmth reaching Earth, crop yields would increase, depressing grain prices.

With that, a 200-year hunt began for links between shifts in the sun's output and changes in climate.

No one doubts that the sun drives Earth's climate. Nor do researchers doubt that over long time spans, changes in the level of sunlight reaching Earth's surface leave their imprints on climate.

The vast bulk of research to date, however, points to greenhouse gases – mainly carbon dioxide from burning coal, oil, and natural gas – as the main force behind the current warming trend, most climate scientists say.

Still, over the past decade some researchers say they've found puzzling correlations between changes in the sun's output and weather and climate patterns on Earth. These links appear to rise above the level of misinterpreted data or faulty equipment.

"There are some empirical bits of evidence that show interesting relationships we don't fully understand," says Drew Shindell, a researcher at NASA's Goddard Institute for Space Studies in New York.

Page 1 | 2 | 3 | 4 | Next Page

Get Monitor stories by e-mail:
(Your e-mail address will be protected by csmonitor.com's tough privacy policy.)
Photos of the Day
The best photos from May 19, 2008.

CAMPAIGN '08 Patchwork Nation
The American voter beyond red and blue

BOOKS When innocence and guilt intertwine
Past and present overlap in Louise Erdrich's lyrical new novel.

Daily podcast

Monitor Reports

Pat Murphy hosts today's podcast with Monitor reporters from around the world.


Today

Pat Murphy

In today's podcast, we hear about Burma allowing foreign aid workers, new tests for China's earthquake relief, rebuilding the Gulf Coast and deadly violence in South Africa.




Today's print issue
Today's Issue of The Christian Science Monitor