SOME of your correspondents continue to perpetuate, irrationally, arguments denying man-made climate change. Generally these are grossly unscientific. A case in point is Rev Dr John Cameron’s contribution (Letters, May 17). His claim that “cooling” is occurring is a statistical quirk of variable measurement and has been addressed many times.

Any scientist, or any individual of an inquisitive bent, with a passing acquaintance of thermodynamics, and planetary motions in our solar system, can readily rationalise the nature of global warming. On the basis of these long-established disciplines it is not difficult to ascertain that the relentless CO2 build-up on Earth, since the industrial revolution, is not associated with any known changes in Earth’s wobbling orbit around the Sun, nor with measureable alterations in the intensity of solar radiation, nor with any variations within the Earth’s core. So what is causing it? Since the first and second laws of thermodynamics have to be satisfied at the global, solar system, and universe, levels, the only rational answer is that the prime mover of global warming must be “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 certainly not.Carbon dioxide wraps our planet in an invisible “blanket”. Unfortunately it is not invisible at infrared frequencies, and heat is trapped.

The debate that remains revolves around the implementation of the transition, which the human race must make, to achieve a fossil fuel-free mode of existence, before the survival of future generations of humans on this planet becomes impossible. The available evidence points to a wholesale adoption of renewable energy sources, backed by massive energy storage techniques, as probably the most effective route forward.

Alan J Sangster,

37 Craigmount Terrace, Edinburgh.