Climate policy

Why measuring fugitive methane emissions from shale gas production matters

  • 24 Jul 2014, 14:40
  • Mat Hope

As an ever-increasing number of countries consider exploiting their shale gas resources, and researchers scramble to understand what a production boom could mean for the climate, two new pieces of research appear to come to opposite conclusions.

What is the climate impact of shale gas?

Since gas has about half the emissions of coal when it's burned for electricity, it has been touted as  a 'bridging fuel' for countries seeking to decarbonise their economies to use as a stop gap on the way to a low carbon electricity system.

But as we've  explored before, scientists are struggling to establish the full impact of increased shale gas production on the climate, due to methane that escapes during the extraction process - known as fugitive methane emissions.

Two papers released this month examine what the actual climate impact of natural gas is. At first glance they seem to show opposite things. The graph on the left, taken from a paper by Robert Howarth appears to show natural gas electricity generation emissions - the towering left bar - can be much higher than coal's. The second graph, from  Heath et al, appears to show the opposite - that coal's generation emissions (on the left) are much higher than those from both conventional and shale gas.

Howarth Vs Heath Coal And Gas Emissions

Both papers examine the 'lifecycle emissions' of the fuels: the amount of gas emitted from extraction to combustion. So why is there such a large discrepancy between two papers?

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UK and Germany top ‘dirty 30’ league of coal plants

  • 22 Jul 2014, 16:45
  • Simon Evans

The UK and Germany are ranked joint first  - or last, depending on your perspective - in a new league table of Europe's 30 most polluting coal-fired power stations.

The ranking comes from several NGOs including WWF and the European Environmental Bureau. They're using it to argue for specific anti-coal policies, saying Europe won't meet its climate targets without them.

We take a look at what they want, and why.

Europe's biggest emitters

The NGOs have listed the EU's top 30 emitters of carbon dioxide in 2013, dubbing the contenders the "dirty 30". All of them are coal-fired power stations.

The UK and Germany both have nine coal plants on the list, putting them joint top of the league table. If you count up the emissions for each country, however, Germany comes out top because its coal plants are generally larger than the UK's and burn more coal.

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Government decides not to amend UK’s fourth carbon budget

  • 22 Jul 2014, 10:35
  • Carbon Brief staff

The government  today announced it will leave the UK's emission reduction targets as they are.

The UK has a legally binding obligation to reduce emissions by 80 per cent by 2050 on 1990 levels. To ensure progress is made at a steady pace, four interim targets were included in the law - known as carbon budgets.

It has been reported for some time that chancellor George Osborne wanted to  weaken these targets, opening the door for increased use of gas power. The government's advisory body, the Committee on Climate Change (CCC), has always maintained there were  no grounds for such a move.

The UK met its first carbon budget and is currently making progress towards the second. The chancellor was reportedly looking to change the  fourth carbon budget, covering the period from 2023 to 2027, which is roughly when new gas capacity might be expected to come online.

The budget requires emissions to be reduced by 50 per cent on 1990 levels in 2025. Having gone through a  review of the basis of the fourth carbon budget, the government today decided to keep that target.

No change of circumstance

The Climate Change Act says the government can legally change the carbon budget if there were  "significant changes" in circumstances since the target was set. Changes in the scientific evidence on climate change, economic circumstances, and the rate at which other countries are decarbonising can all be considered.

Energy and climate change secretary  Ed Davey says  the fourth carbon budget review made it "clear that the evidence does not support amending the budget", with the government's decision being "consistent with the advice of the Committee on Climate Change".

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