There is no opinion, however absurd, which men will not readily embrace as soon as they can be brought to the conviction that it is generally adopted.
Next week marks the deadline that has been set for reactions to the less than satisfactory discussion paper that has emerged from the government’s belated review of the important issue of the economics of climate change.
It is important for David Cameron, too. For, while rightly giving the environment a high priority, he is in danger, over this issue, of making commitments which, in government, he would find it extremely damaging to honour.
Crucial though the economics of climate change is, the starting point clearly has to be the science. I readily admit that I am not a scientist myself; but then the vast majority of those who pronounce with far greater certainty than I shall on this aspect of the issue are not scientists either; and the vast majority of those scientists who speak with great certainty and apparent authority about climate change are not in fact climate scientists at all.
We know for certain only two things. The first is a matter of history rather more than science: namely, that since about 1860, when accurate temperature records were first collected on a comprehensive basis, northern hemisphere temperatures have risen by about 0.6oC; and that this coincides with a steady growth in the amount of carbon dioxide in the atmosphere, a significant part of which is a consequence of industrial and other man-made emissions.
The second is that our planet is kept from being too cold for life as we know it to survive by the so-called greenhouse effect, which traps some of the heat from the sun’s rays. This is overwhelmingly — somewhere between 75 and 95 per cent — caused by clouds and other forms of water vapour; and the carbon dioxide in the atmosphere accounts for most of the remainder.