Cutting carbon dioxide helps prevent drying

Mar 24, 2011

Recent climate modeling has shown that reducing the concentration of carbon dioxide in the atmosphere would give the Earth a wetter climate in the short term. New research from Carnegie Global Ecology scientists Long Cao and Ken Caldeira offers a novel explanation for why climates are wetter when atmospheric carbon dioxide (CO2) concentrations are decreasing. Their findings, published online today by Geophysical Research Letters, show that cutting carbon dioxide concentrations could help prevent droughts caused by global warming.

Cao and Caldeira's new work shows that this precipitation increase is due to the heat-trapping property of the in the atmosphere. Carbon dioxide traps heat in the middle of the atmosphere. This warm air higher in the atmosphere tends to prevent the rising air motions that create thunderstorms and rainfall.

As a result, an increase in the atmospheric concentration of carbon dioxide tends to suppress precipitation. Similarly, a decrease in the atmospheric concentration of carbon dioxide tends to increase precipitation.

The results of this study show that cutting the concentration of precipitation-suppressing carbon dioxide in the atmosphere would increase global precipitation. This is important because scientists are concerned that unchecked could cause already dry areas to get drier. (Global warming may also cause wet areas to get wetter.) Cao and Caldeira's findings indicate that reducing atmospheric carbon dioxide could prevent droughts caused by climate change.

"This study shows that the climate is going to be drier on the way up and wetter on the way down," Caldeira said, adding:"Proposals to cool the earth using geo-engineering tools to reflect sunlight back to space would not cause a similar pulse of wetness."

The team's work shows that carbon dioxide rapidly affects the structure of the atmosphere, causing quick changes precipitation, as well as many other aspects of Earth's climate, well before the greenhouse gas noticeably affects temperature. These results have important implications for understanding the effects of caused by carbon dioxide, as well as the potential effects of reducing concentrations.

"The direct effects of carbon dioxide on precipitation take place quickly," said Cao. "If we could cut carbon dioxide concentrations now, we would see precipitation increase within the year, but it would take many decades for climate to cool."

Explore further: NASA's HS3 looks Hurricane Edouard in the eye

Provided by Carnegie Institution

not rated yet
add to favorites email to friend print save as pdf

Related Stories

Stabilizing climate requires near-zero carbon emissions

Feb 15, 2008

Now that scientists have reached a consensus that carbon dioxide emissions from human activities are the major cause of global warming, the next question is: How can we stop it" Can we just cut back on carbon, or do we need ...

CO2 effects on plants increases global warming

May 03, 2010

Trees and other plants help keep the planet cool, but rising levels of carbon dioxide in the atmosphere are turning down this global air conditioner. According to a new study by researchers at the Carnegie ...

Recommended for you

NASA's HS3 looks Hurricane Edouard in the eye

9 hours ago

NASA and NOAA scientists participating in NASA's Hurricane and Severe Storms Sentinel (HS3) mission used their expert skills, combined with a bit of serendipity on Sept. 17, 2014, to guide the remotely piloted ...

Tropical Storm Rachel dwarfed by developing system 90E

13 hours ago

Tropical Storm Rachel is spinning down west of Mexico's Baja California, and another tropical low pressure area developing off the coast of southwestern Mexico dwarfs the tropical storm. NOAA's GOES-West ...

NASA ocean data shows 'climate dance' of plankton

17 hours ago

The greens and blues of the ocean color from NASA satellite data have provided new insights into how climate and ecosystem processes affect the growth cycles of phytoplankton—microscopic aquatic plants ...

Glaciers in the grand canyon of Mars?

18 hours ago

For decades, planetary geologists have speculated that glaciers might once have crept through Valles Marineris, the 2000-mile-long chasm that constitutes the Grand Canyon of Mars. Using satellite images, ...

NASA support key to glacier mapping efforts

18 hours ago

Thanks in part to support from NASA and the National Science Foundation, scientists have produced the first-ever detailed maps of bedrock beneath glaciers in Greenland and Antarctica. This new data will help ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

omatumr
3 / 5 (2) Mar 24, 2011
[q["If we could cut carbon dioxide concentrations now, we would see precipitation increase within the year, but it would take many decades for climate to cool."

Something is seriously wrong with science when floods and droughts are both blamed on anthropologic global warming (AGW).

With kind regards,
Oliver K. Manuel
PPihkala
1 / 5 (1) Mar 25, 2011
Something is seriously wrong with science when floods and droughts are both blamed on anthropologic global warming (AGW).

No it's not. It just states that places hampered now with droughts are going to see them more and places where there is too much rain will get more. The water in the air just will be more unevenly distributed the more there is CO2 in the air. And even if we discount this reason to lower CO2 pollution, we can not overlook the fact that rising CO2 is acidifying oceans making it much harder to maintain life there.