Climate change presents the greatest challenge to civilised life as we know it and averting climate catastrophe is the most important political task.

Serious efforts to establish a policy framework began about 20 years ago, with the formation of the Intergovernmental Panel on Climate Change and the UN Framework Convention on Climate Change. At that time it appeared that we had several decades in which to bring emissions under control and start to reduce them.

However, policy negotiations have proved intractable and most recently, the UN conference in Copenhagen failed to deliver a meaningful plan of action. At the same time, emissions have continued to rise and environmental changes continue.

Amongst these are warning signs of the "methane time bomb". About 40 percent of methane in the atmosphere comes from natural sources. It is generated by bacteria that break down organic matter. Peat rich lands in northern latitudes were flooded when sea levels rose after the last ice age. The methane in this peat has been locked up in permafrost for thousands of years. As temperatures rise and permafrost begins to melt, scientists have found methane bubbling up from the ocean floor off Siberia, Spitzbergen and Alaska.

Human activities giving rise to methane emissions include natural gas exploration, coal mines, landfill, rice paddies and cattle-rearing. In the UK, it is estimated that over a million tonnes of methane are released each year from landfill. Atmospheric concentration of methane has roughly tripled since pre-industrial times (whereas carbon dioxide has only increased by about one third) but stopped increasing in the 1990s.  Some claimed that efforts to control industrial emissions, including the stopping of leaks by the newly privatised Russian gas industry, were proving effective.

But since 2007, methane levels have again been rising steeply. This is not just concentrated around known sources in the Northern Hemisphere but is happening simultaneously around the globe.

There is a worry that a focus on methane could divert attention away from reducing carbon dioxide emissions. Also, many potential methane capture projects are not being taken forward as carbon markets have been weakened by the financial crisis and failure in Copenhagen. However, in a draft paper in 2007, NASA’s James Hansen argued for dramatic cuts in the release of global warming agents such as methane that have a short residence time in the atmosphere. Methane typically breaks down after about 10 - 12 years - much more quickly than carbon dioxide. However, it is calculated that, of the human contribution to greenhouse gas-driven global warming, methane accounts for around a fifth, or almost two-thirds that of carbon dioxide.

While scientists compare greenhouse gases according to their Global Warming Potential (GWP) over various timeframes, policy-makers have primarily used a 100-year comparison and this has influenced priorities. While over a century, methane is over 20 times more potent than carbon dioxide, over just a 20-year time span it is more than 60 times more potent. It is time to focus on methane.

The Author's Biography

Peter is a director of CarbonSense, a leading independent think tank and innovator in the field of carbon strategy and climate change communication. Founded in 2003, CarbonSense also provides research, consultancy and training for business and public sector clients. Recent innovations include carbon efficiency tools and the Carbon Quilt visualisation services developed in an associated joint venture.

Peter leads process design and research work as well as consulting assignments for clients including businesses, museums and community projects. He is a frequent speaker at conferences and seminars and has been widely published on carbon and sustainability issues over the last twenty years. Peter joined CarbonSense in 2003 after a career developed in the health service, the oil and chemicals sectors and ten years in sustainability consultancy.