Natural Gas Won't Reduce Global Warming, Study Says
Charleston Gazette
12 September 2011
By Ken Ward Jr., Staff writer
Read the study: http://blogs.wvgazette.com/watchdog/
CHARLESTON, W.Va. -- Switching power plants from coal to natural
gas will not help to significantly slow down global warming,
according to the latest in a series of studies to examine the much
promoted role for gas as a "bridge fuel" to cleaner energy
production.
The study, published late last week in the peer-reviewed journal
Climate Change Letters, found that substitution of gas for coal
would result in increased -- rather than decreased -- global
warming for many decades.
Study author Tim Wigley, senior research associate at the National
Center for Atmospheric Research, in Boulder, Colo., used computer
simulations to project temperature changes in various scenarios
where coal is replaced by gas for energy production.
The study is important for West Virginia, where political leaders
are pushing the boom in Marcellus Shale gas drilling as a huge
economic development winner. Along with touting job creation,
natural gas companies promote the notion that they provide a
cleaner option over coal.
But Wigley found that a 50 percent reduction in coal use, along
with a corresponding increase in natural gas use, would lead to a
slight increase in worldwide warming for the next 40 years of
about 0.1 degree Fahrenheit. The reliance on natural gas could
then gradually reduce the rate of global warming, but temperatures
would drop by only a small amount, compared to the 5.4 degrees of
warming projected by 2011 under current energy trends, he found.
"Relying more on natural gas would reduce emissions of carbon
dioxide, but it would do little to solve the climate problem,"
Wigley said. "It would be many decades before it would slow down
global warming at all, and even then it would just be making a
difference around the edges."
Coal is considered the nation's largest source of global-warming
pollution, representing a third of U.S. greenhouse emissions,
equal to the combined output of all cars, trucks, buses, trains
and boats. Most scientists recommend the nation swiftly cut carbon
dioxide emissions, reducing them by about 80 percent below 2000
levels by mid-century to avoid the worst consequences of climate
change.
But some scientists are becoming increasingly concerned about
methane emissions that leak from gas-drilling operations, in part
because methane is a more potent greenhouse gas than carbon
dioxide.
Robert Howarth, a Cornell University ecologist who authored a
widely cited paper on the subject earlier this year, cautions that
switching from coal to natural gas shouldn't divert the country
from bringing on more renewable energy sources.
"It's not saying we should keep burning coal," Howarth said in an
interview. "It's that we should do more to move to what we need to
do in the longer term anyway."
Gas industry supporters, though, point to another study by
researchers at Carnegie Mellon University in Pittsburgh, reporting
the previous conventional wisdom that natural gas produces half
the greenhouse emissions of coal.
"We favor extraction of Marcellus Shale natural gas as long as the
extraction is managed to minimize adverse economic, environmental
and social impacts," said Chris Hendrickson, one of the Carnegie
Mellon study's authors.
The Carnegie Mellon study used different assumptions, including
older estimates of methane leakage from drilling, that could
account for its different results.
Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.