By John Parnell
There is no questioning the logic that replacing dirty coal power plant with their cleaner gas equivalents, is better for the climate.
But the reality is that new gas supplies tend not to replace, but displace high emitting fuels with no overall benefit to the climate.
Localised environmental issues, question marks over the scale of the reserves and long-term implications on energy infrastructure complicate the issue.
As the UK announces it is lifting a ban on fracking, the debate on shale gas and its effect on the climate has reopened.
“Shale gas represents a promising new potential energy resource for the UK. It could contribute significantly to our energy security, reducing our reliance on imported gas, as we move to a low carbon economy,” UK Secretary of State for Energy and Climate Change Ed Davey said.
Others disagree. Friends of the Earth’s Executive Director Andy Atkins argues the move will backfire: “George Osborne’s short-sighted dash for gas will leave the country dependent on dirty fossil fuels”.
So what part, if any, can shale gas have in any country’s transition to a low carbon economy?
Shale gas in the US has cut domestic emissions, but has made no net benefit to the climate. (Credit: BHP Biliton)
Gas v coal
The backbone of the argument in favour of shale gas exploitation is the emission reductions it can yield when swapped for dirtier coal. The UK currently generates just over 40% of its electricity from coal.
In the US, where the most dramatic shale gas exploration has been seen, emissions from the power sector fell by half a billion tons in 2011.
The problem is that the coal that was replaced did not stay in the ground. Much of it was exported to Germany where emissions from the electricity sector grew.
The UK report released today claims that even with the addition of methane leaks from the drilling process, shale gas beats coal.
“The most recent comprehensive review of the evidence, by consultants to the European Commission, concluded that even on worst case assumptions, the carbon footprint of shale gas is likely to be substantially less than that of coal,” states the report.
The ‘shale is better than coal’ argument only works if unwanted, dirtier sources of fuel are not exported to overseas markets. The climate does not differentiate between national emissions – they all count.
Not enough for the climate
The so-called dash for gas, enabled in part by the newfound accessibility of shale reserves, is being presented by many governments as an important part of their climate change action.
US climate negotiator Todd Stern deployed this argument in Doha, citing an 8.6% drop in domestic emissions since 2005.
The International Energy Agency (IEA) launched a set of rules in May 2012 for a environmentally credible pursuit of gas, but stressed it was not enough on its own.
“This report is not a promotion of gas, it is made to show how gas can be used as one of the fuels that bring us closer to a greener energy supply,” Maria van der Hoeven, executive director of the IEA, told RTCC after the event.
“On its own, a higher gas model, with our golden rules scenario, emissions are cut by 1.3% but we’re still looking at a rise CO2 levels of 650ppm which is about 3.5°C,” she said.
“But let’s be honest, it’s not the solution, it’s just part of the solution. We have to invest in low carbon technology, we have to invest in energy efficiency and renewables. If we do that then we can reach that greener future,” she emphasised.
Environmental groups are concerned that investment in domestic gas and supporting infrastructure will detract from a drive to expand renewables, which offer a clearer route to restricting warming to 2°C above pre-industrial levels.
Locked in
There is a degree of carbon lock-in with fossil fuels. Gas plants built now to burn shale stocks will still be around in 40 years. Compare this timescale to the 2017 deadline to avoid 2°C of warming and the problem emerges.
The IEA says we can only afford to burn one third of the world’s known fossil fuel reserves in order to keep within this limit to avoid dangerous warming.
The UK has a self-enforced carbon budget to ensure its emissions stay within a set limit.
There is no carbon budget on what resources are extracted and then burned at home or abroad. The UK can cap its own ring-fenced emissions but adding to the global supply of fossil fuels only feeds a global addiction. The sum total of emissions worldwide is the only statistic that the climate cares about.
The demand for coal from India and China ensures that as developed countries use new domestic gas supplies to meet climate goals, those without greenhouse gas targets are ready and willing buyers of fuels being driven into obsolescence by rising environmental regulation.
Embarrassment of riches
Nothing derails a good environmental track record like the discovery of new fossil fuels. Canada has become a “pariah” state in the climate change talks according to many observers since its vast tar sand oil became economically viable.
The UK was the first nation in the world to develop a carbon budget – a move that is now being emulated in other countries. As recently as last week at the UN climate change negotiations in Doha, the UK was praised by NGOs for showing leadership on climate change finance.
Successive governments have noted the UK’s potential to lead the world on clean offshore wind and marine energy.
The prospect of domestic gas riches, the scale of which is disputed, provides an excuse to blow renewable ambitions backwards. It provides finance ministries with a compelling argument to sidestep those commitments and join the dash for gas.
Local environmental problems
The most common example of the local environmental problems are the now infamous images from the Gasland documentary showing residents in the US setting fire to their tap water and claiming that it had been contaminated from nearby shale gas drilling.
What is reported less is the fact that an investigation found that the methane in the water system in that area was from natural leakage, not the direct result of fracking.
Gas can migrate through rock formations without any encouragement making the assessment of the impact of shale gas exploration on local water supplies and methane leaks into the atmosphere difficult.
Seismic tremors related to the high pressure fracturing of the rock have been observed widely in the US and it was their presence that halted test wells in the UK.
These are largely small and insignificant but there is evidence that an earthquake measuring 5.6 on the Richter scale was the result of shale gas exploration.
Water use is also an issue with a typical shale gas well using 10-30m litres of clean water. This at a time when many countries are facing drought conditions.
Without more work to quantify all of these risks, it is impossible to accurately judge the fracking impact on these criteria. Some environmentalists consider them a red herring distracting from the long term threat that 4°C of warming would bring.