I SUGGESTED in a letter several weeks ago that those who reject the established consensus on the reality of human-induced climate change are guilty of 'cherry-picking' their evidence, ie to select those bits of evidence which support their case, and ignoring the evidence that doesn't.

Recent letters referring to 'The Science and Public Policy Institute' and to the 'Manhattan Declaration' and to Dr David Bellamy only reinforce my suggestion. We can quote other people's opinions in this forum forever without getting anywhere. Few of your letter-writers or readers are in a position to perform climate-related experiments, or review the whole of the research evidence. So as in many fields, whether medicine, engineering or law, we look to an un-biased respected source to test drugs, and keep aeroplanes flying. We have to look critically at the sources of information, and ask ourselves , 'Is this source or person an acknowledged expert ?' 'What do his or her peers think of his/her views ?' 'What are the scientific credentials of this source ?' 'How can I judge if this source is truly un-biased or if the opinions might be coloured by self-interest?'

The scientific method requires that all evidence is published and peer-reviewed, ie checked by colleagues, and experiments and models constantly re-run and checked for accuracy and consistency. An overwhelming majority, 97 per cent of scientists agree that climate change is "very likely" caused by human activity (US National Academy of Sciences).

What kind of conspiracy theory explains that? The United Nations Intergovernmental Panel on Climate Change, the IPCC, is charged with reviewing ALL the work relating to the field. It doesn't have a theory which it is trying to find evidence for, it is objective.

So, when it comes to the reality or not of man-made climate change, do we believe those sources funded and promoted by isolated special interest groups and people with financial interests in business-as-usual, or do we keep our trust in the long-established scientific method, and in the publicly funded bodies charged with its execution.

CLIVE PERKINS Cirencester