Fracking tremors

sir – Earthquakes occur when the pressures created by movements of subterranean strata overcome the opposing force of friction. The longer the pressure builds up, the more violent the quake.

In California, lubricants are pumped into the San Andreas Fault to cause multiple tremors, in order to avoid the devastating damage that would be caused by a single major event.

Fracking does not cause earthquakes (report, November 2), but may trigger benign tremors that protect people from the far more harmful effects of a major quake.

There may be many legitimate objections to fracking, but the causing of earthquakes is not one of them. Stephen Byrne

Okehampton, Devon

sir – On Tuesday night it was cold. On Wednesday morning, British electricity demand was about 39 gigawatts. Of this, less than 5 per cent was from wind and solar, while gas provided 60 per cent, nuclear 20 per cent and coal 5 per cent.

Such mornings will always occur. Even if we increased wind and solar by five times to replace gas, this would not satisfy our current energy needs, never mind the increased demand when all cars and homes are electric. Michael Hughes

Newbury, Berkshire

sir – According to the Committee on Climate Change’s net zero plan, even by 2050 we will need almost as much gas as we do now for electricity generation and conversion to hydrogen for heating.

The ban on fracking will merely increase our dependence on imports. Paul Homewood

Sheffield, South Yorkshire