Nations must cut their emissions very quickly if they are to limit the extent of global emissions: that’s the conclusion of a new report out yesterday from the Intergovernmental Panel on Climate Change (IPCC).
Some media outlets have focused on an IPCC spokesperson’s apparent endorsement of shale gas as a way to mitigate global warming. But a look at the summary reveals gas has to be deployed with caution if countries are to reduce emissions and limit the extent of climate change.
The report is the third and final in a series assessing the state of climate change. It tackles the measures nations will have to take to limit climate change to the internationally-agreed threshold of two degrees above pre-industrial levels.
At present, the IPCC has only released its Summary for Policymakers (SPM) – a document intended to distil the main messages of the full report for global decisionmakers. More detailed chapters are due to be released later this week.
The energy sector will have to play a big part in emissions reduction, the IPCC says, indicating that the amount of power generated by renewable and low-carbon sources of energy must increase dramatically.
Shale gas and the IPCC
Speaking to reporters, Professor Ottmar Edenhofer, co-chairman of the IPCC authors, said:
“The shale gas revolution can be very consistent with low-carbon development – that is quite clear. It can be very helpful as a bridge technology.”
The Mail calls the “unexpected endorsement” a blow to “green activists who seek cuts in greenhouse gas emissions but are concerned about the effects of fracking”.
So which of the report’s conclusions could apply to shale gas, and how should we understand them in the context of the overall findings?
Emissions and the energy sector
Globally, emissions need to come down by 40 to 70 per cent by 2050, and all the way down to zero by 2100, the SPM notes.
The energy sector is responsible for around 35 per cent of global annual greenhouse gas emissions. And the rise in emissions over the last decade is due in large part to coal power’s increasing share in the energy mix.
To keep within the two degree target, unabated fossil fuel burning would need to be almost completely phased out by 2100. Meanwhile, the share of energy from low-carbon sources from wind and solar power to nuclear energy must increase triple or quadruple by the middle of the century, the report concludes.
The SPM says natural gas may play a limited role in getting emissions down – specifically emissions from burning coal. Although natural gas still produces greenhouse gases that warm the climate, it produces about half the amount that coal does.
According to the text, emissions from energy supply could be significantly cut “by replacing current world average coal-fired power plants with modern, highly efficient natural gas combined-cycle power plants or combined heat and power plants”.
That’s on the condition that there’s natural gas available, and emissions associated with extracting the gas and piping it to power sources are kept low.
Replacing coal plants with highly efficient gas plants could serve as a “bridge technology” to other, lower carbon energy sources, the report notes.
But to be consistent with limiting warming to two degrees, gas production would need to peak and decline to below current levels by 2050, and decline further in the second half of the century.
Beyond that time, any fossil fuel power plants, including gas, would have to be fitted with carbon capture facilities to suck plants’ emissions out of the air.
Both the Mail and the Sun wrongly assign Edenhofer’s quote to the report itself. In a comment piece, the Sun goes on to say the IPCC cites shale gas as a “vital energy source”. In fact, the SPM does not mention shale gas at all.
In addition, both stories report only half of Edenhofer’s quote. According to the Sunday Times, Edenhofer went on to qualify his statement, cautioning, as the report does, that burning more gas would only cut emissions if it displaced coal, a point the other stories neglect to mention.
The report contains other important caveats. First, beyond 2050 – when the IPCC says emissions must have reduced by 40 to 70 per cent – any fossil fuel power plants, including gas, would have to be fitted with carbon capture facilities to suck plants’ emissions out of the air.
And the IPCC’s comments on so-called fugitive emissions – greenhouse gases that escape when gas is being extracted or transported – are particularly significant for shale gas. Keywan Riahi, director of energy at the International Institute of Applied Systems analysis and a lead author of the new report, tells Carbon Brief:
“The [report] clearly shows that unabated fossil fuels need to be phased out over the long-term, and this is also the case for natural gas, including shale gas. There might however be short-term opportunities for conventional natural gas to replace coal power plants. This opportunity might not be there for shale gas, however. The report clearly cautions against shale gas because of concerns with regards to fugitive emissions.”
The whole picture
The IPCC’s message is clear: it’s essential to reduce emissions significantly, starting now. But it doesn’t tell governments what to do or what technologies to use: they must make up their own minds about how to achieve the needed reductions in greenhouse gases.
It indicates that natural gas could play a role in the decarbonisation effort – but only in a controlled way, as a substitute for higher-emitting coal, and with emissions from the energy sector as a whole shrinking rapidly throughout this century.