Navigation Links
Global methane levels on the rise again

After eight years of near-zero growth in atmospheric methane concentrations, levels have again started to rise.

"This is not good news for future global warming," says CSIRO's Dr Paul Fraser, who co-authored a paper to be published in Geophysical Research Letters, a journal of the American Geophysical Union.

"Over recent years, the growth of important greenhouse gases, namely methane and the CFCs, had slowed. This tended to offset the increasing growth rate of carbon dioxide that results mainly from large increases in the consumption of fossil fuels, particularly in the developing world.

"Now that methane levels have resumed their growth, global warming may accelerate."

Methane is the second most important greenhouse gas in the atmosphere after carbon dioxide, accounting for nearly 20 per cent of global warming since the industrial revolution.

Methane is emitted to the atmosphere from natural wetlands, rice fields, cattle, forest and grassland fires, coal mines, natural gas leakage and use, and other sources.

"Over the past decade these methane sources have been close to balancing the absorption of methane through atmospheric oxidation and into dry soil," Dr Fraser says.

"This fragile balance has resulted in little growth of methane in the atmosphere. Apparently some sources have been increasing, such as from fossil fuel use, cattle, and rice, while others have been decreasing, particularly natural tropical wetlands. However, over the past year, the total sources have overwhelmed the total sinks, and methane has again started to rise."

Dr Fraser says that recent analyses of global data by CSIRO and collaborators at the Massachusetts Institute of Technology, Scripps Institution of Oceanography and the University of Bristol suggest that the methane increase is, at least in part, due to methane releases in the high latitudes of the Northern Hemisphere.

"Such increases have been predicted as rapid Arctic ice melting creates more high latitude wetland sources," says Dr Fraser.

"A possible additional cause of the methane increase is that atmospheric oxidation may be weakening, for reasons as yet unknown, although recovery from ozone depletion, which is predicted to have commenced, may be involved."

The Intergovernmental Panel on Climate Change (IPCC) has identified the need to understand causes of the variations of methane growth rates as a priority area of research. "The reality is that scientists have only a very basic understanding of these methane variations," Dr Fraser says.

"In order to predict the future contribution of methane to climate change, continuing high-quality observations, in particular in tropical and boreal locations, are required as input to, and verification of, sophisticated climate models."


Contact: Craig Macaulay
CSIRO Australia

Related biology news :

1. Global Warming and the Habitability of Planet Earth, Sept. 26
2. Green skies: Engineers work may reduce jet travels role in global warming
3. Scientists in first global study of poison gas in the atmosphere
4. North Americas northernmost lake affected by global warming
5. IEEE-USA innovation forum will help prepare US tech leaders to prosper in a global marketplace
6. Majority of Americans want local action on global warming, says poll
7. International team of scientists warns of climate changes impact on global river flow
8. Changing the global dietary environment
9. Global deal fuels QUTs world-changing research
10. NIH hosts event to launch Council of Science Editors global theme issue
11. Agricultural soil erosion is not adding to global warming
Post Your Comments:
(Date:10/6/2015)... , Oct. 6, 2015 Track Group, ... today that it has signed a contract with the ... across the full range of sentences under the Department,s ... of the Americas. "This contract with the Virginia DOC ... the US and advances our position as a trusted ...
(Date:10/5/2015)... ) releases ... (NASDAQ: NXTD ), a biometric authentication company focused ... ) releases the following market and ... a biometric authentication company focused on the growing mobile ... ) releases the following market and ...
(Date:10/1/2015)... Oct. 1, 2015  Biometrics includes diverse set ... body characteristics, such as fingerprints, eye retinas, facial ... of biometrics technology has been constantly increasing in ... five years. In addition to the most prominent ... recognition, other means of biometric authentication are rapidly ...
Breaking Biology News(10 mins):
(Date:10/12/2015)... Oct. 12, 2015 /PRNewswire/ - Aeterna Zentaris Inc. (NASDAQ: ... engaged in developing and commercializing novel treatments in oncology, ... Dennis Turpin , the Company,s former Senior Vice ... its Quebec City office.  ... Chief Executive Officer of the Company commented, "After a ...
(Date:10/12/2015)... October 12, 2015 LabStyle Innovations ... Management Solution, today announced its Medical Director, Dr. ... at MobiHealth,s 5th EAI International Conference on Wireless ... through innovations in mobile and wireless technologies," the conference ... from October 14 - 16, 2015. The conference ...
(Date:10/12/2015)... , Oct. 12, 2015 VolitionRx Limited ... a completed clinical study of its NuQ ® blood-based ... the online issue of Clinical Epigenetics , the official ... conducted in collaboration with Lund University, ... Andersson , MD, PhD, Professor of Surgery and Vice-Dean, Faculty ...
(Date:10/12/2015)... Seattle WA (PRWEB) , ... October 12, 2015 , ... ... for the treatment of retinal diseases that can safely and chronically be administered as ... Global Health Impact Forum co-hosted by The Cleveland Clinic and taking place October 25th ...
Breaking Biology Technology: