The announcement in the chancellor's autumn statement of tax breaks for fracking shale gas and approval for more than 30 gas-fired power stations is bad for the environment, energy security, and our economy (Report, 6 December).
Although burning a tonne of natural gas produces about half the CO2 compared with a tonne of coal or oil, this is only part of the story. A recent paper in Nature Climate Change shows that CO2 from burning the world's reserves of fracked gas is enough on its own to warm the planet by 3C. A further recent report from the highly respected Tyndall Centre for Climate Change has concluded that the reduction in CO2 emissions resulting from the switch from coal to gas in the US has been entirely offset by the export of the coal saved.
A similar argument can be applied to the UK, as North Sea oil saved by burning shale gas in place of gas will not remain in the ground. Moreover, when the life cycle emissions of greenhouse gases from producing fracked gas are taken into consideration, four recent papers in highly respected peer-reviewed journals show that a switch to gas from coal or oil for electricity generation, or from petrol and diesel for transport, is unlikely to mitigate global warming. Science tells us fracked gas is not better than coal or oil to keep climate change in check.
Depletion of reserves has played a part in the decline in US natural gas production since September 2011. This and the high cost of fracking makes shale gas uneconomic to exploit according to the US gas industry analyst George Berman. Thus the US shale gas bubble appears to be close to bursting. Why does George Osborne think the UK, with its much smaller shale gas reserves, can buck these trends?
Money spent on gas only delays the urgent and inevitable need to switch to renewables, and to invest in a smart grid and energy storage to meet UK targets for lower greenhouse gas emissions. Renewable energy will give us energy independence, cheaper energy production and underpin future economic prosperity.
Prof David Knight, Prof Robert Whitmarsh, Dr Anton Page, Robin Speed, Claire Jones
Science and Technology Advisory Panel, Winchester Action on Climate Change
• The UK's green economy has grown steadily even as the rest of the economy struggles, showing that action to avert dangerous climate change is not a luxury for the good times – it can help turn our economy around. With climate change already being felt by wildlife and people, particularly the world's poorest, we need to do all we can to fight it.
We call on the government to take its climate commitments seriously – and reap the rewards of a green economy at the same time. In light of the chancellor's gas strategy, we need the government to explain how it reconciles its plans with the climate change committee's warning that it will breach our legislated carbon targets.
Neil Thorns Cafod, Martin Harper RSPB, Christine Allen Christian Aid, John Sauven Greenpeace, David Nussbaum WWF-UK, Paul Cook Tearfund, Andy Atkins Friends of the Earth, Kathleen Spencer Chapman Oxfam, Louise Hazan People & Planet, Isobel Tarr UKYCC
• Dominic Raab (Comment, 5 December) prefers a "shift away from inflating consumer energy bills [caused by] gambling on existing inefficient and expensive renewable technologies" and a move "towards an environmental policy that makes wider economic sense". Well it's good to know that, in Mr Raab's view, "economy trumps planet" and that the electorate can look forward to cheap energy. Unfortunately the planet doesn't play by Mr Raab's (or even Mr Osborne's) rules and those who will have to clean up after this generation has pumped poisonous chemicals (used in fracking) into the groundwater and has created even larger piles of radioactive waste are not here to comment.
• Michael Jacobs is right (Comment, 3 December): the battles whose outcome will determine whether we avoid catastrophic climate change are being fought not in Doha but in energy and finance ministries around the world and in the boardrooms of energy companies and their bankers.
That's very worrying because neither the ministries nor the boardrooms, let alone the banks, are committed to ensuring the necessary global reductions in global warming emissions called for by climate scientists. They all have other agendas. They are not co-ordinated. Climate change requires a global system to ensure that the overall reduction in emissions called for by climate scientists is achieved.
The initiative has to come from civil society. We could establish a new independent global institution, a global climate commons trust, which could take evidence from climate scientists, set a cap on the overall global production of fossil fuels in each of the next 10 years, print production permits, auction the permits and distribute the net proceeds of sale to all citizens of the world equally. Implementation of such a scheme would require the co-operation of corporations and governments.
Cloughjordan, Co Tipperary, Ireland
• About 10 years ago ministers were urging us to unplug our phone chargers at night to reduce our carbon footprint. I wonder for how many thousands of years I will have to remove my charger at night to offset the carbon put into the atmosphere by a space tourist, whether flying on the fringe of space or visiting the moon (Report, 7 December).
Brian P Moss
• To talk of "saving the planet" has doctor/patient overtones (You can't ignore this, 1 December). It also puts us at one remove due to the individual impossibility of the task. The planet doesn't need saving – it will deal with us very nicely.