Evidence counters claims that world is suffering unprecedented warm spell

THERE has been some interesting and thought-provoking recent correspondence in your Letters column on the topic of man-made global-warming.

But there are some further points that should be borne in mind. For instance, the Piri Reis map, dated 1513, shows the coastline of Antarctica (according to the US Air Force), which is still buried under a huge quantity of ice. Could it have been mapped by the Chinese fleet that circumnavigated the globe in the 1420s?

A recent melting of ice in the Alps revealed a pass which was clearly in use during the Roman and Medieval periods. Carbon-dating of plant remains in Greenland at a location from which the ice has recently retreated shows that the roots dated from the time that the Vikings settled there around 1000AD, clearly finding its climate congenial.

According to NASA's Goddard Institute for Space Studies, the warmest years of the 20th century were, in order: 1934, 1998, 1921, 2006, 1931, 1999, 1953, 1990, 1938 and 1939. So six of the top ten were more than 50 years ago; five were 70 or more years ago. Proponents of the "greenhouse gas" hypothesis explain that recent alleged global warming has been caused by the increase in output of by cars, planes and industry since the Second World War and especially since the 1970s. Do they have explanations for the points I have raised, or will they simply scream that I am denying facts, when, like most of us, I simply want a credible explanation of a phenomenon which seems readily explicable and not particularly alarming?

ANDREW HN GRAY

Craiglea Drive

Edinburgh

Paul Chitnis (Letters, 2 July) claims: "Doing our fair share to tackle climate change is a simple matter of justice" and "It is perfectly reasonable to claim that Scotland can punch above its weight by showing other countries what can and must be achieved."

I can only assume he was not watching the BBC news channel on 24 June, which said: "SNP ministers acknowledged an 80 per cent cut in emissions in itself would make no difference on a global scale."

It may well be the case that, "the poorest and most vulnerable, whose carbon footprints are virtually negligible are the most exposed to the dangers of climate change", although I note Mr Chitnis did not use the term "man made climate change", but there are far better ways of improving the lot of such people than setting meaningless carbon cutting targets and signing up to worthless bits of legislation such as the Climate Change (Scotland) Bill.

NEIL McKINNON

Tulchan Garden

Glenalmond, Perth

I do hope Bill Jamieson (26 June) is right. Then my grandchildren can continue in the habits we have taught them – profligate use of energy as if there is no tomorrow. I welcome the Scottish Climate Bill as yet another wake-up call to all of us. There is evidence that oil is becoming more difficult and expensive to extract. Consequently, we should be learning to use less of it.

Burning any fossil fuel and producing ever-increasing concentrations of carbon dioxide runs the risk, of climate change, with potentially catastrophic damage to lives and food supplies. Surely we owe it to the next generation to reduce that risk. If the dangers turn out to be less than many fear, some actions, for example increasing insulation of buildings, will save money and provide employment now. The Climate Bill encourages such action.

DR JOHANNA CURRIE

Caiystane View

Edinburgh