THE request by your readers for Holyrood to issue hard facts on wind farms in Scotland (Letters, August 18) will never be met as there is a wall of silence on this topic. However, until the Growth Commission report is issued, here are a few facts that may assist your readers to understand the economics of renewable energy.

The first is that electricity is three times more expensive than gas, hence replacing domestic gas will see a vast increase in energy bills for Scottish consumers. In addition, electricity from offshore wind farms is paid a subsidy of £100 per MWhour plus the current grid price, or three times that from Combined Cycle Gas Turbines (CCGT) units.

If the data in a paper written by Professor G Hughes (of Edinburgh University) are correct then wear and tear on wind turbine blades means that the units only have a 10-year life instead of the design figure of 25 years with a further increase in the cost.

The cost of the Neart na Goithe wind farm is given as £5 million per MW installed. Scots use six times more energy from gas than that from electricity, hence phasing out gas means a £420 billion price to install sufficient wind farms. MSPs have never indicated how Scottish consumers can meet such a bill.

The final fact is that there is 12,000 MW of generation to meet a maximum demand of only 5,000 MW yet MSPs have never explained why additional plant is required. I trust these facts assist Lyndsey Ward et al in understanding the financial impact the policies of our MSPs will have on their future energy bills

Ian Moir,

79 Queen Street, Castle Douglas.

ROY Turnbull (Letters, August 17) uses cherrry-picked data to justify his contention that global warming is ongoing but, granted, opinions differ, as always, choice of time-years being an import cause of disparities in conclusions.

However, science does not at all fully understand the multiple influences on our always-changing climate. Decarbonisation of the world's energy generation might just induce some stabilisation, but at a devastating global cost, which the "big emitters" have no intention of meeting. To close down our own, trivial proportionate contribution would be like failing to drain the ocean with a teaspoon. Those moved by some perceived moral imperative discount more immediate, pressing demands on our efforts and financial resources, including the vital need to repair our indebted economy.

The scientific method consists of constructing hypotheses, then seeking verification. There is no proof of causality in the CO2-climate change relationship.

Politicians and scientists in the West have latched on to industrial and domestic decarbonisation without considering the bigger picture, so we must logically review these commitments such as targets for CO2 output.

Charles Wardrop,

11 Viewlands Road West, Perth.

Dr RM Morris (Letters, August 17) attacks your cartoonist Steven Camley for using the title of Al Gore’s film An Inconvenient Truth in what he describes as a denigratory way. Some might think Al Gore’s apocalyptic claims are worthy of a little gentle satire.

Dr Morris then takes aim, apparently with a straight face, at “unnecessary support to those who deny climate change”. I think he may mean, in his denigratory way, people like me who question whether there is quite such a direct human and catastrophic link to global warming as he and Mr Gore seem to think. I don’t know anyone who denies that climate changes.

In order to evaluate his claim that solar energy is practical in Scotland, it would be helpful to know the quantity of subsidies, in cash or kind, his solar panels have generated over the years. Taxpayers have a legitimate interest in that figure.

Councillor Cameron Rose (Conservative, Southside Newington),

Edinburgh City Council, City Chambers, Edinburgh.

IN relation to the global warming debate, Philip Adams (Letters, August 18) raises the issue of scientific scepticism. All genuine scientists are sceptical in relation to the hypotheses that underpin their area of research, otherwise science would not advance. However this is rather different from scepticism prompted by over-enthusiastic media reporting of junk science and the predilection of journalists for irresponsibly stirring up debate where none exists.

For example, while biologists may be dubious about the validity of some theories as to the precise mechanism which causes carcinogenic materials in smoke to trigger cell mutation, the public should not be sceptical about the solidity of the science and should be reassured that smoking is not advisable. Furthermore, would Mr Adams desist from stopping someone from jumping out of an aircraft without a parachute, because of the remaining uncertainties in gravitational theory, which remain because of the elusive graviton?

The greenhouse effect was discovered in 1824 by Fourier, the heat-rapping properties of CO2 and other gases were first measured by Tyndall in 1859, the climate sensitivity to CO2 was first computed in 1896 by Arrhenius, and by the 1950s the scientific foundations were pretty much understood. The following aspects of climate change are scientific fact: the concentration of carbon dioxide in the atmosphere is increasing more rapidly than in the last 3000 years, carbon dioxide is a greenhouse gas, carbon dioxide persists in the atmosphere for a very long time, climate change is not due to solar activity, climate change is not due to volcanic eruptions. Any scientist, or any individual of an inquisitive bent, with a passing acquaintance of thermodynamics, is therefore bound to ask – if the CO2 build-p on Earth is not associated with changes in the Sun’s output, or the Earth’s core, what is causing it? The first and second laws of thermodynamics have to be satisfied, and the only rational answer is that the source is "ancient sunlight" released by the burning of fossil fuels. While the direct heat released into the atmosphere from homes, power stations, factories and vehicles is negligible the added carbon from ancient forests is not.

The thermal blanket which we are wrapping around the globe will result in planetary warming. What is unknown, or difficult to predict, as the IVth Working Report of the Intergovernmental Panel on Climate Change makes perfectly clear, is how warm it will get and how quickly.

Alan J Sangster,

37 Craigmount Terrace,

Edinburgh.