Among the objections to
fracking is the fact the process releases quantities of methane, a
greenhouse gas often reckoned to be at least 20 times more powerful than
carbon dioxide at warming the atmosphere. That is the comparison we have
often used in the Network's reporting. It's right, so far as it goes.
But by some calculations it doesn't go nearly far enough.
Recently an observant reader
pointed out that methane is 20 times more potent than CO2 when its
impact is measured over a century. But in the short term it is a far
greater problem. Over the space of two decades it is estimated to be at
least 84 times more damaging than carbon dioxide.
Robert Howarth is professor
of ecology and environmental biology at Cornell University. He and his
colleague Drew Shindell of the US National Oceanic and Atmospheric
Administration have predicted that unless emissions of methane (and
black carbon) are reduced immediately, the Earth will warm by 1.5°C by
2030 and by 2.0°C by between 2045 and 2050, whether or not carbon
dioxide emissions are reduced.
Professor Howarth puts the
global warming potential of methane higher still. He has written: "At
the time scale of 20 years following emission, methane’s global warming
potential is more than 100-fold greater than for carbon dioxide (Shindell
et al. 2009)."
Some critics will conclude
that the IPCC's search for a bridging strategy to move us rapidly to a
world of clean energy has scored an own goal by failing to rule out a
fuel which entails a large and avoidable increase in greenhouse
emissions. The cost of the infrastructure needed to exploit shale gas on
a large scale may also work to prolong its use.
Ironically, the clean energy
world the IPCC seeks need be no more than 15 years away, according to
one US expert. Mark Z Jacobson is professor of civil and environmental
engineering at Stanford University, California, and director of its
atmosphere and energy program. He believes that wind, water and solar
power can be scaled up cost-effectively to meet the world's energy
demands, ending dependence on both fossil fuels and nuclear power.
Professor Jacobson described
in Energy Policy in 2010 how he and a colleague had analysed "the
feasibility of providing worldwide energy for all purposes (electric
power, transportation, heating/cooling, etc.) from wind, water, and
He continued: "We suggest
producing all new energy with WWS by 2030 and replacing the pre-existing
energy by 2050. Barriers to the plan are primarily social and political,
not technological or economic. The energy cost in a WWS world should be
similar to that today."
It sounds like a less risky
path to a world of clean energy than the IPCC is urging. Fifteen years
to build a different way of fuelling society, or 20 years of watching
spiralling methane emissions, seems a no-brainer.
Climate News Network