Featured Research

from universities, journals, and other organizations

New global warming culprit: Methane emissions jump dramatically during dam drawdowns

Date:
August 8, 2012
Source:
Washington State University
Summary:
Researchers have documented an underappreciated suite of players in global warming: dams, the water reservoirs behind them, and surges of greenhouse gases as water levels go up and down. In separate studies, researchers saw methane levels jump 20- and 36-fold during drawdowns.

Release of water over a dam. Washington State University researchers have documented an underappreciated suite of players in global warming: dams, the water reservoirs behind them, and surges of greenhouse gases as water levels go up and down.
Credit: Belinda Pretorius / Fotolia

Washington State University researchers have documented an underappreciated suite of players in global warming: dams, the water reservoirs behind them, and surges of greenhouse gases as water levels go up and down.

Related Articles


Bridget Deemer, a doctoral student at Washington State University-Vancouver, measured dissolved gases in the water column of Lacamas Lake in Clark County and found methane emissions jumped 20-fold when the water level was drawn down. A fellow WSU-Vancouver student, Maria Glavin, sampled bubbles rising from the lake mud and measured a 36-fold increase in methane during a drawdown.

Methane is 25 times more effective than carbon dioxide at trapping heat in the atmosphere. And while dams and the water behind them cover only a small portion of Earth's surface, they harbor biological activity that can produce large amounts of greenhouse gases. There are also some 80,000 dams in the United States alone, according to the U.S. Army Corps of Engineers National Inventory of Dams.

"Reservoirs have typically been looked at as a green energy source," says Deemer. "But their role in greenhouse gas emissions has been overlooked."

Deemer and Glavin's findings will be on display this week in a poster session at the national meeting of the Ecological Society of America in Portland.

Their efforts are part of a larger attempt to appreciate the role of lakes, reservoirs and streams in releasing greenhouse gases. A study published last year in the journal Science conservatively estimated that the ability of terrestrial ecosystems to act as carbon sinks, storing greenhouse gases, could be one-fourth less than estimated once emissions from reservoirs are considered.

The WSU-Vancouver work is the first to actually demonstrate and quantify the relationship between water-level drawdowns and greenhouse gas releases, says John Harrison, Deemer and Glavin's advisor and an assistant professor of Earth and Environmental Sciences.

The research could lead to different ways of managing drawdowns, he says, as emissions may be higher in summer months, when warmer temperatures and low oxygen conditions in bottom waters stimulate the microbial activity that produces greenhouse gases.

"We have the ability to manage the timing, magnitude and speed of reservoir drawdowns, which all could play a role in how much methane gets released to the atmosphere," Harrison says.

Managers can also consider the optimal time to take out a dam, Deemer says. While a dam removal may lead to some greenhouse gas emissions initially, she says it will be a one-time occurrence, while emissions can recur with regular drawdowns. The ability of soils and plants to store greenhouse gases could also make reservoir decommissioning a net sink, she says, but researchers "simply don't know at this point."

With Army Corps of Engineers funding, Deemer now plans to look at three other reservoirs in Oregon and northern California's Klamath basin.


Story Source:

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


Cite This Page:

Washington State University. "New global warming culprit: Methane emissions jump dramatically during dam drawdowns." ScienceDaily. ScienceDaily, 8 August 2012. <www.sciencedaily.com/releases/2012/08/120808081420.htm>.
Washington State University. (2012, August 8). New global warming culprit: Methane emissions jump dramatically during dam drawdowns. ScienceDaily. Retrieved November 23, 2014 from www.sciencedaily.com/releases/2012/08/120808081420.htm
Washington State University. "New global warming culprit: Methane emissions jump dramatically during dam drawdowns." ScienceDaily. www.sciencedaily.com/releases/2012/08/120808081420.htm (accessed November 23, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Sunday, November 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Anglerfish Rarely Seen In Its Habitat Will Haunt You

Anglerfish Rarely Seen In Its Habitat Will Haunt You

Newsy (Nov. 22, 2014) For the first time Monterey Bay Aquarium recorded a video of the elusive, creepy and rarely seen anglerfish. Video provided by Newsy
Powered by NewsLook.com
Raw: Buffalo Residents Digging Out, Helping out

Raw: Buffalo Residents Digging Out, Helping out

AP (Nov. 22, 2014) Hundreds of volunteers joined a 'shovel brigade' in Buffalo, New York on Saturday, as the city was living up to its nickname, "The City of Good Neighbors." Video provided by AP
Powered by NewsLook.com
Toyota's Hydrogen Fuel-Cell Green Car Soon Available in the US

Toyota's Hydrogen Fuel-Cell Green Car Soon Available in the US

AFP (Nov. 21, 2014) Toyota presented its hydrogen fuel-cell compact car called "Mirai" to US consumers at the Los Angeles auto show. The car should go on sale in 2015 for around $60.000. It combines stored hydrogen with oxygen to generate its own power. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Google Announces Improvements To Balloon-Borne Wi-Fi Project

Google Announces Improvements To Balloon-Borne Wi-Fi Project

Newsy (Nov. 21, 2014) In a blog post, Google said its balloons have traveled 3 million kilometers since the start of Project Loon. Video provided by Newsy
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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