No
matter how you drill it, using natural gas as an energy source is a
smart move in the battle against global climate change and a good
transition step on the road toward low-carbon energy from wind, solar
and nuclear power.
That
is the conclusion of a new study by Cornell Professor Lawrence M.
Cathles, published in the most recent edition of the peer-reviewed
journal Geochemistry, Geophysics and Geosystems. Cathles, a faculty
member in Cornell’s Department of Earth and Atmospheric Sciences,
reviewed the most recent government and industry data on natural gas
“leakage rates” during extraction, as well as recently developed climate
models.
He
concluded that no matter the timeframe considered, substituting natural
gas energy for all coal and some oil production provides about 40% of
the global warming benefit that a complete switch to low-carbon sources
would deliver.
“From
a greenhouse point of view, it would be better to replace coal
electrical facilities with nuclear plants, wind farms and solar panels,
but replacing them with natural gas stations will be faster, cheaper and
achieve 40% of the low-carbon-fast benefit,” Cathles writes in the
study. “Gas is a natural transition fuel that could represent the
biggest stabilization wedge available to us.”
Cathles
study, “Assessing the Greenhouse Impact of Natural Gas,” includes
additional findings about expanding the use of natural gas as an energy
source, and the climate impact of “unconventional” gas drilling methods,
including hydraulic fracturing in shale formations. They include:
- Although
a more rapid transition to natural gas from coal and some oil produces a
greater overall benefit for climate change, the 40% of low-carbon
energy benefit remains no matter how quickly the transition is made, and
no matter the effect of ocean modulation or other climate regulating
forces. - Although
some critics of natural gas as a transition fuel have cited leakage
rates as high as 8% or more of total production during
drilling—particularly hydraulic fracturing extraction—more recent
industry data and a critical examination of Environmental Protection
Agency data supports leakage rates closer to 1.5% for both conventional
and hydrofractured wells. - Even
at higher leakage rates, using natural gas as a transition to
low-carbon energy sources is still a better policy than “business as
usual” with coal and oil, due to the different rates of decay (and hence
long-term global warming effect) of CO2 released in greater amounts by
burning coal and oil and any methane released during natural gas
extraction. - Using
natural gas as a transition fuel supports the push to low-carbon
sources by providing the “surge capacity” when needed, or a buffer when
solar and wind production wanes.
“The
most important message of the calculations reported here is that
substituting natural gas for coal and oil is a significant way to reduce
greenhouse forcing, regardless of how long the substitution takes,”
Cathles writes. “A faster transition to low-carbon energy sources would
decrease greenhouse warming further, but the substitution of natural gas
for other fossil fuels is equally beneficial in percentage terms no
matter how fast the transition.”
Cathles’ study can be found online at: http://bit.ly/NiAsaG.
Geochemistry,
Geophysics and Geosystems is an online journal published by the
nonprofit American Geophysical Union. Cathles’ research received no
outside funding.
Source: Cornell University
