Featured Research

from universities, journals, and other organizations

Brighter clouds, cooler climate? Organic vapors affect clouds, leading to previously unidentified climate cooling

Date:
May 5, 2013
Source:
Manchester University
Summary:
Scientists have shown that natural emissions and humanmade pollutants can both have an unexpected cooling effect on Earth's climate by making clouds brighter.

Natural emissions and humanmade pollutants can both have an unexpected cooling effect on the world's climate by making clouds brighter.
Credit: Yuriy Kulik / Fotolia

University of Manchester scientists, writing in the journal Nature Geoscience, have shown that natural emissions and humanmade pollutants can both have an unexpected cooling effect on Earth's climate by making clouds brighter.

Clouds are made of water droplets, condensed onto tiny particles suspended in the air. When the air is humid enough, the particles swell into cloud droplets. It has been known for some decades that the number of these particles and their size control how bright the clouds appear from the top, controlling the efficiency with which clouds scatter sunlight back into space. A major challenge for climate science is to understand and quantify these effects which have a major impact in polluted regions.

The tiny seed particles can either be natural (for example, sea spray or dust) or humanmade pollutants (from vehicle exhausts or industrial activity). These particles often contain a large amount of organic material and these compounds are quite volatile, so in warm conditions exist as a vapour (in much the same way as a perfume is liquid but gives off an aroma when it evaporates on warm skin).

The researchers found that the effect acts in reverse in the atmosphere as volatile organic compounds from pollution or from the biosphere evaporate and give off characteristic aromas, such as the pine smells from forest, but under moist cooler conditions where clouds form, the molecules prefer to be liquid and make larger particles that are more effective seeds for cloud droplets.

"We discovered that organic compounds such as those formed from forest emissions or from vehicle exhaust, affect the number of droplets in a cloud and hence its brightness, so affecting climate," said study author Professor Gordon McFiggans, from the University of Manchester's School of Earth, Atmospheric and Environmental Sciences.

"We developed a model and made predictions of a substantially enhanced number of cloud droplets from an atmospherically reasonable amount of organic gases.

"More cloud droplets lead to brighter cloud when viewed from above, reflecting more incoming sunlight. We did some calculations of the effects on climate and found that the cooling effect on global climate of the increase in cloud seed effectiveness is at least as great as the previously found entire uncertainty in the effect of pollution on clouds."


Story Source:

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


Journal Reference:

  1. David Topping, Paul Connolly, Gordon McFiggans. Cloud droplet number enhanced by co-condensation of organic vapours. Nature Geoscience, 2013; DOI: 10.1038/ngeo1809

Cite This Page:

Manchester University. "Brighter clouds, cooler climate? Organic vapors affect clouds, leading to previously unidentified climate cooling." ScienceDaily. ScienceDaily, 5 May 2013. <www.sciencedaily.com/releases/2013/05/130505145839.htm>.
Manchester University. (2013, May 5). Brighter clouds, cooler climate? Organic vapors affect clouds, leading to previously unidentified climate cooling. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2013/05/130505145839.htm
Manchester University. "Brighter clouds, cooler climate? Organic vapors affect clouds, leading to previously unidentified climate cooling." ScienceDaily. www.sciencedaily.com/releases/2013/05/130505145839.htm (accessed July 30, 2014).

Share This




More Earth & Climate News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Climate Change Could Cost Billions, According To White House

Climate Change Could Cost Billions, According To White House

Newsy (July 29, 2014) A report from the White House warns not curbing greenhouse gas emissions could cost the U.S. billions. Video provided by Newsy
Powered by NewsLook.com
Climate Change Could Cost Billions According To White House

Climate Change Could Cost Billions According To White House

Newsy (July 29, 2014) A report from the White House warns not curbing greenhouse gas emissions could cost the U.S. billions. Video provided by Newsy
Powered by NewsLook.com
Jane Goodall Warns Great Apes Face Extinction

Jane Goodall Warns Great Apes Face Extinction

AFP (July 29, 2014) The world's great apes face extinction within decades, renowned chimpanzee expert Jane Goodall warned Tuesday in a call to arms to ensure man's closest relatives are not wiped out. Duration: 00:58 Video provided by AFP
Powered by NewsLook.com
Rat Infestation at Paris' Tuileries Garden

Rat Infestation at Paris' Tuileries Garden

AFP (July 29, 2014) An infestation of rats is causing concern among tourists at Paris' most famous park -- the Tuileries garden next to the Louvre Museum. Duration: 00:54 Video provided by AFP
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