Navigation Links
Greenhouse gas impact of hydroelectric reservoirs downgraded
Date:8/1/2011

An international team of scientists has amassed the largest data set to date on greenhouse gas emissions from hydroelectric reservoirs. Their analysis, published today in the online version of Nature Geoscience, posits that these human-made systems emit about 1/6 of the carbon dioxide and methane previously attributed to them.

Prior studies based on more limited data cautioned that hydroelectric reservoirs could be a significant and large source of both carbon dioxide and methane to the atmosphere.

Through an analysis of 85 globally-distributed hydroelectric reservoirs, the authors revealed that these systems emit 48 million metric tons of carbon annually, a downgrade from earlier estimates of 321 million metric tons. Further putting things in perspective, hydroelectric reservoirs are responsible for less than 16% of the total carbon dioxide and methane emissions from all types of human-made reservoirs combined.

"Our analysis indicates that hydroelectric reservoirs are not major contributors to the greenhouse gas problem," comments Dr. Jonathan Cole, a limnologist at the Cary Institute of Ecosystem Studies and one of the paper's authors. "But there are some caveats. To date, only 17% of potential hydroelectric reservoir sites have been exploited, and impacts vary based on reservoir age, size, and location."

Carbon dioxide and methane are two of the main greenhouse gases created by human activities. Carbon dioxide is produced during the combustion of nearly any organic material; methane has a variety of industrial sources. Both gases are also produced naturally, particularly in wetlands and lakes.

When rivers are dammed to make the reservoirs needed for hydroelectricity, flooding creates lake-like conditions that generate carbon dioxide and methane. Emissions are the highest following reservoir construction, due to decomposing vegetation and soil organic matter. As reservoirs age, emissions decline, with cold-water systems stabilizing more rapidly than their warm-water counterparts.

Lead author MSc. Nathan Barros, of the Federal University of Juiz de Fora further explains, "The bottom line is that per unit of energy, hydroelectric generation produces much less carbon dioxide and methane emissions than previously thought, but impacts are not equal across all landscapes."

The amount of greenhouse gases generated by hydroelectric reservoirs depends on where they are built, with the team's analysis indicating that emissions are correlated with latitude and the amount of biomass in the watershed. With Barros adding, "Reservoirs in tropical locations, such as the Amazon, emit more methane and carbon throughout their lifecycles."

Hydroelectricity supplies an estimated 20% of the world's electricity and accounts for more than 85% of electricity from renewable sources. Future development is expected globally.

The paper's authors urge careful consideration of site location and design. "During the environmental impact phase, it should be a goal to minimize the amount of carbon dioxide and methane emitted per unit of energy generated," Cole notes.

To truly tease apart the emissions generated by hydroelectricity, the authors also call for a study that assesses a site's carbon budget before and after reservoir construction. Pre- and post flooding analysis would clarify the net carbon impact of hydroelectric reservoirs.


'/>"/>

Contact: Lori M. Quillen
quillenl@caryinstitute.org
845-677-7600 x233
Cary Institute of Ecosystem Studies
Source:Eurekalert  

Related biology news :

1. Study finds greenhouse gas reduction strategy may be safe for soil animals
2. Greenhouse ocean study offers warning for future
3. Greenhouse gases from forest soils
4. New information provides sustainable options for greenhouse operations
5. Can biochar help suppress greenhouse gases?
6. Solar greenhouses: Chinas winning solution to global energy crisis
7. Arctic climate variation under ancient greenhouse conditions
8. Neiker-Tecnalia creates air-conditioned greenhouse with alternative energies
9. The undead may influence biodiversity, greenhouse gas emissions
10. MU scientists find new farming method to reduce greenhouse gases, increase farm yields
11. Freshwater methane release changes greenhouse gas equation
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Greenhouse gas impact of hydroelectric reservoirs downgraded
(Date:6/21/2016)... , June 21, 2016 NuData Security announced ... new role of principal product architect and that ... director of customer development. Both will report directly ... officer. The moves reflect NuData,s strategic growth in ... to high customer demand and customer focus values. ...
(Date:6/9/2016)...  Perkotek an innovation leader in attendance control systems is proud to announce the ... employers to make sure the right employees are actually signing in, and to even ... ... ... ...
(Date:6/2/2016)... 2, 2016 The Department of Transport ... the 44 million US Dollar project, for the , ... including Personalization, Enrolment, and IT Infrastructure , to ... production and implementation of Identity Management Solutions. Numerous renowned international ... Decatur was selected for the most compliant ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... OTTAWA, ON (PRWEB) , ... June 23, 2016 , ... ... former DNA Technical Leader at the Arkansas State Crime Laboratory, has joined STACS DNA ... joining the STACS DNA team,” said Jocelyn Tremblay, President and COO of STACS DNA. ...
(Date:6/23/2016)... Ky. , June 23, 2016 ... two Phase 1 clinical trials of its complement ... placebo-controlled, single and multiple ascending dose studies designed ... pharmacodynamics (PD) of subcutaneous injection in healthy adult ... subcutaneously (SC) either as a single dose (ranging ...
(Date:6/23/2016)... June 23, 2016 ... 2016;12(1):22-8 http://doi.org/10.17925/OHR.2016.12.01.22 Published recently ... peer-reviewed journal from touchONCOLOGY, Andrew D Zelenetz ... of cancer care is placing an increasing burden ... expensive biologic therapies. With the patents on many ...
(Date:6/23/2016)... ... June 23, 2016 , ... ClinCapture, the only free validated ... will showcase its product’s latest features from June 26 to June 30, 2016 ... on Disrupting Clinical Trials in The Cloud during the conference. DIA (Drug ...
Breaking Biology Technology: