Featured Research

from universities, journals, and other organizations

Deforestation causes cooling in Northern U.S., Canada, study finds

Date:
November 17, 2011
Source:
University of California - Davis
Summary:
The impact of deforestation on global warming varies with latitude, according to new research from a team of scientists representing 20 institutions from around the world. The finding calls for new climate-monitoring strategies, researchers say.

The research shows cooling effects at higher latitudes but no indication deforestation is cooling lower latitudes.
Credit: UC Davis archival photo

The impact of deforestation on global warming varies with latitude, according to new research from a team of scientists representing 20 institutions from around the world. The surprising finding, which researchers say calls for new climate-monitoring strategies, will be published in the Nov. 17 issue of the journal Nature.

"It depends where the deforestation is," said UC Davis atmospheric science Professor Kyaw Tha Paw U, a study co-author. "It could have some cooling effects at the regional scale, at higher latitudes, but there's no indication deforestation is cooling lower latitudes, and in fact may actually cause warming."

"Because surface station observations are made in grassy fields with biophysical properties of cleared land, they do not accurately represent the state of climate for 30 percent of the terrestrial surface covered by forests," the study says.

Paw U and his colleagues found that deforestation in the boreal region, north of 45 degrees latitude, results in a net cooling effect. While cutting down trees releases carbon into the atmosphere, it also increases an area's albedo, or reflection of sunlight. Surface temperatures in open, nonforested, high-latitude areas were cooler because these surfaces reflected the sun's rays, while nearby forested areas absorbed the sun's heat. At night, without the albedo effect, open land continued to cool faster than forests, which force warm turbulent air from aloft to the ground.

"People are debating whether afforestation is a good idea in high latitudes," said Xuhui Lee, the study's principal investigator and professor of meteorology at the Yale School of Forestry & Environmental Studies. "If you plant trees you sequester carbon, which is a benefit to the climate system. At the same time, if you plant trees you warm the landscape because trees are darker compared to other vegetation types. So they absorb solar radiation."

Paw U emphasized that the findings should not be viewed as a "green light" to cut down forests in high latitudes. "The intent is to clarify where we can see these regional effects using actual temperature measurements," he said. "Besides absorbing carbon dioxide, forest ecosystems have a number of other valuable qualities, even if at certain latitudes they may be warmer than open areas."

The researchers calculated that north of Minnesota, or above 45 degrees latitude, deforestation was associated with an average temperature decrease of 1.5 degrees Fahrenheit. On the other hand, deforestation south of North Carolina, or below 35 degrees latitude, appeared to cause warming. Statistically insignificant cooling occurred between these two latitudes.

The researchers collected temperature data from a network of specialized weather stations in forests ranging from Florida to Manitoba and compared results with nearby stations situated in open grassy areas that were used as a proxy for deforested land.

"The cooling effect is linear with latitude, so the farther north you go, the cooler you get with deforestation," said Lee.

David Hollinger, a scientist with the USDA Forest Service and study co-author, said, "Another way to look at the results is that the climate cooling benefits of planting forests is compounded as you move toward the tropics."

The study was supported, in part, by grants from the U.S. Department of Energy and the Yale Climate and Energy Institute.


Story Source:

The above story is based on materials provided by University of California - Davis. Note: Materials may be edited for content and length.


Journal Reference:

  1. Xuhui Lee, Michael L. Goulden, David Y. Hollinger, Alan Barr, T. Andrew Black, Gil Bohrer, Rosvel Bracho, Bert Drake, Allen Goldstein, Lianhong Gu, Gabriel Katul, Thomas Kolb, Beverly E. Law, Hank Margolis, Tilden Meyers, Russell Monson, William Munger, Ram Oren, Kyaw Tha Paw U, Andrew D. Richardson, Hans Peter Schmid, Ralf Staebler, Steven Wofsy, Lei Zhao. Observed increase in local cooling effect of deforestation at higher latitudes. Nature, 2011; 479 (7373): 384 DOI: 10.1038/nature10588

Cite This Page:

University of California - Davis. "Deforestation causes cooling in Northern U.S., Canada, study finds." ScienceDaily. ScienceDaily, 17 November 2011. <www.sciencedaily.com/releases/2011/11/111116132910.htm>.
University of California - Davis. (2011, November 17). Deforestation causes cooling in Northern U.S., Canada, study finds. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2011/11/111116132910.htm
University of California - Davis. "Deforestation causes cooling in Northern U.S., Canada, study finds." ScienceDaily. www.sciencedaily.com/releases/2011/11/111116132910.htm (accessed September 2, 2014).

Share This




More Earth & Climate News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Iceland Lowers Aviation Alert on Volcano

Iceland Lowers Aviation Alert on Volcano

AFP (Sep. 1, 2014) Iceland has lowered its aviation alert on its largest volcano after a fresh eruption on a nearby lava field prompted authorities to enforce a flight ban for several hours. Duration: 01:07 Video provided by AFP
Powered by NewsLook.com
Lightning Hurts 3 on NYC Beach

Lightning Hurts 3 on NYC Beach

AP (Sep. 1, 2014) A lightning strike injured three people on a New York City beach on Sunday. The storms also delayed flights and interrupted play at the US Open tennis tournament. (Sept. 1) Video provided by AP
Powered by NewsLook.com
Thailand Totters Towards Waste Crisis

Thailand Totters Towards Waste Crisis

AFP (Sep. 1, 2014) Fears are mounting in Bangkok that poor planning and lax law enforcement are tipping Thailand towards a waste crisis. Duration: 01:21 Video provided by AFP
Powered by NewsLook.com
Melting Ice Shelves Drive Rapid Antarctic Sea Level Rise

Melting Ice Shelves Drive Rapid Antarctic Sea Level Rise

Newsy (Sep. 1, 2014) A study of almost 20 years' worth of satellite images shows Antarctic sea levels are on the rise as ice shelves continue to melt. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins