Sir – I have read with interest the article about fracking and local people’s fears about it (Report, July 4). It has been agreed internationally that a rise of two degrees Celsius in the global mean temperature could pose risks to human civilisation.

I also understand that to burn all the currently known reserves of fossil fuels would cause a global temperature rise far above this.

Therefore any attempt to exploit yet more reserves should be treated with extreme caution. The UK now has an energy security problem because much of our North Sea oil was squandered (some of it to pay for the dole) and we failed to keep some nuclear options open.

While I am all in favour of developing the know-how for fracking as an insurance policy against energy shortages, we should endeavour to keep these reserves in the ground for as long as possible.

John Killick, Abingdon