SIR Ian Wood, rather predictably, avers that North Sea oil is draining away and that before long, he suggests, somewhat illogically, Scotland will "in 20, 30 or 40 years time" be forced to import fracked gas from England ("Salmond faces grilling after tycoon warns oil running out", The Herald, August 21).

Clearly, Sir Ian is failing to keep in touch with the findings on climate change which are a major threat to his former industry. Dwindling fossil fuel reserves are not a problem either for Scotland or the world. There is plenty to warm the planet into an irretrievable death spiral. If we are to preserve an ecologically healthy planet, it will be necessary in 20 to 30 years for mankind to have abandoned fossil fuels in favour of renewable energy. In these circum­stances, support for any proposal that the UK should resort to extracting shale gas, by sanctioning fracking, is simply inexplicable. However, it will not happen for several reasons.

The residents of northern England are well aware of the earth tremors which accompanied fracking tests near Blackpool, and will be wary of fracking in their neighbourhoods, and so they should be. Recent research reported in a geological sciences journal points to direct links between fracking in the US and a magnitude 5.7 earthquake in the near vicinity. This is not an insignificant event.

They should also be concerned that extensive testing near shale gas extraction wells in the United States has discovered that ground water pollution has occurred within a one- mile radius of the well head for nearly all wells tested. This is further compounded by the detection, by satellite, of serious methane leakage into the atmosphere from the vicinity of the majority of fracking installations. Methane is a powerful greenhouse gas.

In the US some of these disadvantages of fracking can be tolerated because the wells exist in the vast expanses of meagerly populated terrain. Nevertheless, recent reports suggest that even the gung-ho Americans are beginning to question this technology. In crowded Britain the technology has little chance of securing public acceptance.

The Yes campaign in the independence debate should be acknowledging that the exploitation of fossil fuels as a source of energy has to be terminated by 2030, and that an independent Scotland will be in the vanguard of European nations seeking to use the remaining fossil fuel window to vigorously transition to a renewables-based economy.

Alan J Sangster,

37 Craigmount Terrace, Edinburgh.

At the final Holyrood debate before the referendum, Alex Salmond insisted that 24 billion barrels of oil could be extracted from the North Sea despite the fact that this amount almost certainly does not exist in recoverable form ("Salmond denies exaggerating oil reserve figures", The Herald, August 22). His party then used its parliamentary majority to pass a motion that an independent Scotland would be "greener" as well as fairer and more prosperous.

Quite how our country could be greener whilst extracting and burning 24 billion barrels of fossil fuel is anyone's guess. Quite how the Scottish Greens can square this particular circle and support the SNP is also a matter of conjecture.

It is surely fitting that the First Minister and his fellow separatists concluded this final session using the shameless blend of paradox, deceit, and contradiction that has characterised the Yes campaign for the past two years.

Derek Miller,

Westbank, West Balgrochan Road,