There was a recent exchange of letters in the Advertiser concerning perceived cooling or warming in the global climate, and I would like add some further comment.

There is thought, by many, to be a consensus about the science of climate change.

Others continue to be sceptical about this consensus, and especially of the certainty often expressed by its supporters.

Part of such concern arises from the fact that the greenhouse gas effect can only occur in the atmosphere, but climate models use surface data to support their theory in regard to the cause of warming.

If it is true that such surface warming is the result of the greenhouse effect, it must be that the warming should be much more apparent in the atmosphere.

The forecasts made by climate models of dramatic surface warming are just not evident in the atmosphere.

The assertion, therefore, that the greenhouse gas effect in the atmosphere can be the cause of an even greater warming on the surface is a logical jump that needs some explaining.

There is now some new interest in the phenomenon known as ‘groupthink’ in which a group of people look at the world in a way that is very important to them, but is not based on evidence.

Indeed, they may reject anything that does not fit in with their consensus, so great is their certainty.

Proper debate cannot, then, take place because those holding contrary views must be ignored or dismissed as not worth listening to.

I would like to think that readers of the Advertiser will not fall into this trap.

Real debate on the matter is vital to proper national energy policy.  ­— ROBERT SHEPPARD, Hillside, Beckingham.