Navigation Links
Carbon dioxide controls Earth's temperature
Date:10/14/2010

NEW YORK -- Water vapor and clouds are the major contributors to Earth's greenhouse effect, but a new atmosphere-ocean climate modeling study shows that the planet's temperature ultimately depends on the atmospheric level of carbon dioxide.

The study, conducted by Andrew Lacis and colleagues at NASA's Goddard Institute for Space Studies (GISS) in New York, examined the nature of Earth's greenhouse effect and clarified the role that greenhouse gases and clouds play in absorbing outgoing infrared radiation. Notably, the team identified non-condensing greenhouse gases -- such as carbon dioxide, methane, nitrous oxide, ozone, and chlorofluorocarbons -- as providing the core support for the terrestrial greenhouse effect.

Without non-condensing greenhouse gases, water vapor and clouds would be unable to provide the feedback mechanisms that amplify the greenhouse effect. The study's results will be published Friday, Oct. 15 in Science.

A companion study led by GISS co-author Gavin Schmidt that has been accepted for publication in the Journal of Geophysical Research shows that carbon dioxide accounts for about 20 percent of the greenhouse effect, water vapor and clouds together account for 75 percent, and minor gases and aerosols make up the remaining five percent. However, it is the 25 percent non-condensing greenhouse gas component, which includes carbon dioxide, that is the key factor in sustaining Earth's greenhouse effect. By this accounting, carbon dioxide is responsible for 80 percent of the radiative forcing that sustains the Earth's greenhouse effect.

The climate forcing experiment described in Science was simple in design and concept -- all of the non-condensing greenhouse gases and aerosols were zeroed out, and the global climate model was run forward in time to see what would happen to the greenhouse effect.

Without the sustaining support by the non-condensing greenhouse gases, Earth's greenhouse effect collapsed as water vapor quickly precipitated from the atmosphere, plunging the model Earth into an icebound state -- a clear demonstration that water vapor, although contributing 50 percent of the total greenhouse warming, acts as a feedback process, and as such, cannot by itself uphold the Earth's greenhouse effect.

"Our climate modeling simulation should be viewed as an experiment in atmospheric physics, illustrating a cause and effect problem which allowed us to gain a better understanding of the working mechanics of Earth's greenhouse effect, and enabled us to demonstrate the direct relationship that exists between rising atmospheric carbon dioxide and rising global temperature," Lacis said.

The study ties in to the geologic record in which carbon dioxide levels have oscillated between approximately 180 parts per million during ice ages, and about 280 parts per million during warmer interglacial periods. To provide perspective to the nearly 1 C (1.8 F) increase in global temperature over the past century, it is estimated that the global mean temperature difference between the extremes of the ice age and interglacial periods is only about 5 C (9 F).

"When carbon dioxide increases, more water vapor returns to the atmosphere. This is what helped to melt the glaciers that once covered New York City," said co-author David Rind, of NASA's Goddard Institute for Space Studies. "Today we are in uncharted territory as carbon dioxide approaches 390 parts per million in what has been referred to as the 'superinterglacial.'"

"The bottom line is that atmospheric carbon dioxide acts as a thermostat in regulating the temperature of Earth," Lacis said. "The Intergovernmental Panel on Climate Change has fully documented the fact that industrial activity is responsible for the rapidly increasing levels of atmospheric carbon dioxide and other greenhouse gases. It is not surprising then that global warming can be linked directly to the observed increase in atmospheric carbon dioxide and to human industrial activity in general."


'/>"/>

Contact: Kathryn Hansen
kathryn.h.hansen@nasa.gov
301-614-5883
NASA/Goddard Space Flight Center
Source:Eurekalert

Related biology news :

1. Carbon nanostructures form the future of electronics and optoelectronics
2. Growth in the global carbon budget
3. Carbon sinks: Issues, markets, policy
4. Carbon dioxide scrubber captures greenhouse gases
5. UNC study on properties of carbon nanotubes, water could have wide-ranging implications
6. Study: Tropical wetlands hold more carbon than temperate marshes
7. Diatom genome helps explain success in trapping excess carbon in oceans
8. Earthworm activity can alter forests carbon-carrying capabilities
9. Global warming predicted to hasten carbon release from peat bogs
10. Revised theory suggests carbon dioxide levels already in danger zone
11. Engineer to present leak-proof method for carbon dioxide storage at international conference
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:1/25/2016)... SEATTLE , Jan. 25, 2016  Glencoe Software, ... biotech, pharma and publication industries, will provide the data ... Phenotypic Screening Centre (NPSC). ... Phenotypic analysis ... even whole organisms, allowing comparisons between states such as ...
(Date:1/20/2016)... --  MedNet Solutions , an innovative SaaS-based eClinical technology ... is pleased to announce the attainment of record-setting corporate ... of the company,s laser focus on (and growing international ... comprehensive, easy-to-use and highly affordable cloud-based technology platform. ... growth achievements in 2015 include: , Record ...
(Date:1/13/2016)... 2016 http://www.researchandmarkets.com/research/7h6hnn/india_biometrics ... the  "India Biometrics Authentication & Identification ...  report to their offering.  ... the addition of the  "India Biometrics ... & Forecast (2015-2020)"  report to ...
Breaking Biology News(10 mins):
(Date:2/10/2016)... ... 2016 , ... LATHAM, NEW YORK... Marktech Optoelectronics will feature their ... in San Francisco’s Moscone Center from February 16-18, 2016, and at the healthcare-focused BiOS ... InGaAs PIN diode standard packages feature a TO-46 metal can with active areas of ...
(Date:2/10/2016)... ... February 10, 2016 , ... ... research registry built on the secure online PatientCrossroads platform, has exceeded both its ... participants have joined the PROMPT study, which seeks to advance understanding of the ...
(Date:2/10/2016)... ... 10, 2016 , ... Global Stem Cells Group, ... Global Stem Cells Network (GSCN) and its affiliate Global Medical Training Network ... adipose and bone marrow therapies. , Through the new collaboration, Global Stem ...
(Date:2/10/2016)... ... February 09, 2016 , ... Creation ... winner of the Highest Overall Customer Rating Award from Circuits Assembly , today ... units across the USA, Canada, Mexico and China. , The EMS provider, known ...
Breaking Biology Technology: