Your feature on fracking generally identifies and addresses the main issues surrounding this topic (The truth about fracking in Scotland, State of the nation, February 19). However, from a climate change perspective it is perhaps not irrelevant to point out that the fossil fuel industry has a long history of pursuing practices which are inimical to the environment. Consequently, claims by the industry that it will adhere to strict regulatory frameworks are difficult to take seriously.

In the USA, where regulations are admittedly lax, satellite observations of huge oil and gas basins in East Texas and North Dakota confirm staggering 9 and 10 per cent leakage rates of heat-trapping methane. If this is attributable to poorly regulated extraction processes it is very worrying, but if it is due to unavoidable natural seepage induced by the fracking process, then the case is made for blocking further developments in the more difficult geology of Scotland.

At these levels of methane leakage, fracking actually speeds up human-caused climate change because methane (CH4) is a super-potent greenhouse gas, which traps 86 times as much heat as carbon dioxide over a 20-year period. So even small leaks in the natural gas production and delivery system can have a large climate impact – enough to totally undermine the entire benefit of switching from coal-fired power to gas.

Fairly simple calculations demonstrate that if the fracking industry’s leakage rate were 5.4 per cent, replacing a fleet of coal plants with gas plants would be worse for the climate for 50 years. If the leakage rate were 7.6 per cent, fracked gas is worse that continuing to burn coal for a century.

The bottom line is that fracking speeds up global warming and has no net climate benefit whatsoever in any timescale that matters to humanity. The only safe route toward bequeathing a healthy planet to future generations is whole-scale adoption of renewable technologies.

Alan J Sangster

Edinburgh