Natural gas can only be a worthwhile bridge to a low
carbon future if a series of tough conditions are met, according to
working paper from the influential New Climate Economy
The paper says the climate benefits of gas, including
shale gas, could in theory be significant. It suggests a 10%
increase in global gas supplies could prevent 500 gigawatts (GW) of
new coal capacity being added by 2035, avoiding 1.3 billion tonnes
of annual carbon dioxide (CO2) emissions.
But it warns that any theoretical benefits could
easily be wiped out without controls on methane leakage, limits on
total energy use and targets to ensure low-carbon energy sources
are not displaced.
The North American shale gas revolution has
drive down emissions from US electricity supplies. The US
shift from coal- to gas-fired power stations has been driven,
though perhaps only in part, by market forces because fracking
has made US gas cheaper.
The US example is often cited as evidence that gas can
act as a lower-carbon bridge to a low-carbon future. Gas advocates
argue it could help the world avoid new coal-fired power stations
and close down old ones, halving carbon emissions per unit of
electricity in the process.
For instance in a
recent interview with Energy Post, Jérôme Ferrier, president of
the International Gas Union says that gas, the "cleanest fossil
fuel", can play a key role in limiting global warming. He says that
the great challenge for the world is to move from coal to gas.
The new working paper, jointly authored by the New Climate
Economy initiative and the Stockholm Environment
Institute, questions the premise of the gas bridge.
First, it shows how emissions from relatively
efficient "super-critical" coal plants can be halved with a switch
to gas supplied through pipelines. In climate terms, this is the
best-case scenario for added gas use, with each 1GW coal plant
replaced by gas saving nearly 3 million tonnes of CO2 per year.