Featured Research

from universities, journals, and other organizations

New Climate Model Predicts Greater 21st Century Warming

Date:
May 21, 2003
Source:
American Geophysical Union
Summary:
For the first time, scientists have incorporated multiple human and natural factors into a climate projection model. They predict that increased carbon dioxide in the atmosphere, due to changes in the carbon cycle, combined with a decrease in human-produced sulphates, may cause accelerated global warming during the 21st century, as compared with simulations without these feedback effects.

WASHINGTON - For the first time, scientists have incorporated multiple human and natural factors into a climate projection model. They predict that increased carbon dioxide in the atmosphere, due to changes in the carbon cycle, combined with a decrease in human-produced sulphates, may cause accelerated global warming during the 21st century, as compared with simulations without these feedback effects.

Results of the study, completed by Chris D. Jones and colleagues at the Met Office's Hadley Centre for Climate Prediction and Research in Bracknell, United Kingdom, appear in the journal Geophysical Research Letters, published by the American Geophysical Union.

Previous studies have indicated that human activities, such as carbon dioxide and sulphate emissions, as well as natural factors, such as changes in solar radiation, emissions from volcanic eruptions and interactions between climate and the carbon cycle, are important mechanisms for causing climate change. No previous climate studies have, however, integrated all of these factors into a single climate experiment.

The climate-carbon cycle experiment completed by Jones and his colleagues is the first to take a more comprehensive Earth-systems approach to climate modeling. This "all-forcings experiment," or ALL, incorporates carbon dioxide emissions, non-carbon dioxide greenhouse gases, human-produced sulphate aerosol levels, the reflection of solar radiation associated with sulphate in the atmosphere (the "albedo effect"), atmospheric ozone levels, levels of solar radiation, the effects of volcanic eruptions, and climate-carbon cycle feedbacks.

Discrepancies between observed temperature trends in the 20th century and climate simulations that consider only a limited number of factors have hindered the ability of some models to predict future climate change. The ALL model was, however, able to recreate observed temperature records for the 20th century, illustrating the importance of including multiple factors in climate change projections. Also, the rise in carbon dioxide simulated by ALL more closely matches the observed carbon dioxide rise than did previous models. The researchers say that this indicates that mechanisms other than direct carbon dioxide emissions caused by human activity also contribute to the observed trend. Jones and his colleagues were also able to replicate estimates of the amount of carbon currently stored in the oceans and on land worldwide.

With regard to future climate predictions, ALL shows that predicted reductions in human sulphate emissions will cause a reduction in the cooling effect associated with sulphates in the atmosphere, or a net warming. The model predicts that the resultant warming will enhance soil respiration, meaning that the increased amounts of carbon stored in the soil during the 20th century will be released into the atmosphere, causing a faster rise in atmospheric carbon dioxide. By the end of the 21st century, the authors state, the increase in carbon dioxide and decrease of sulphates will cause a substantially higher global warming of 5.5 degrees Celsius [9.9 degrees Fahrenheit] compared with 4 degrees Celsius [7 degrees Fahrenheit] when these interactions are neglected.

###The research was supported by the UK Department for the Environment, Food and Regional Affairs.


Story Source:

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


Cite This Page:

American Geophysical Union. "New Climate Model Predicts Greater 21st Century Warming." ScienceDaily. ScienceDaily, 21 May 2003. <www.sciencedaily.com/releases/2003/05/030521092312.htm>.
American Geophysical Union. (2003, May 21). New Climate Model Predicts Greater 21st Century Warming. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2003/05/030521092312.htm
American Geophysical Union. "New Climate Model Predicts Greater 21st Century Warming." ScienceDaily. www.sciencedaily.com/releases/2003/05/030521092312.htm (accessed July 23, 2014).

Share This




More Earth & Climate News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Observation Boat to Protect Cetaceans During Ship Transfer

Observation Boat to Protect Cetaceans During Ship Transfer

AFP (July 22, 2014) As part of the 14-ship convoy that will accompany the Costa Concordia from the port of Giglio to the port of Genoa, there will be a boat carrying experts to look out for dolphins and whales from crossing the path of the Concordia. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
New Orleans Plans to Recycle Cigarette Butts

New Orleans Plans to Recycle Cigarette Butts

AP (July 21, 2014) New Orleans is the first U.S. city to participate in a large-scale recycling effort for cigarette butts. The city is rolling out dozens of containers for smokers to use when they discard their butts. (July 21) Video provided by AP
Powered by NewsLook.com
Shark Sightings a Big Catch for Cape Tourism

Shark Sightings a Big Catch for Cape Tourism

AP (July 21, 2014) A rise in shark sightings along the shores of Chatham, Massachusetts is driving a surge of eager vacationers to the beach town looking to catch a glimpse of a great white. (July 21) Video provided by AP
Powered by NewsLook.com
Spectacular Lightning Storm Hits London

Spectacular Lightning Storm Hits London

AFP (July 19, 2014) A spectaCular lightning storm struck the UK overnight Friday. Images of lightning strikes over the Shard and Tower Bridge in central London. Duration: 00:23 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