Believers in doom by global warming are fond of telling us that if we fail to act now to limit climate change it will be too late. If nothing is done, it seems we will shortly pass one or another ill-defined ‘tipping point’, beyond which the world will slide ever faster towards human oblivion.
It is always a bit difficult to nail down the exact nature of any of these supposed tipping points. They normally crop up in conversation while accompanied by a good deal of hand waving. But as a general rule they seem to be spin-offs from the proposition that man is ‘exponentially’ increasing the concentration of carbon dioxide in the atmosphere. That is to say, the carbon dioxide increase is occurring faster and faster. As a consequence, so too is the increase of Earth’s temperature.
Pretty soon, disastrous things will happen so quickly that it will be impossible for humans to adapt.
The problem with this theory is that the world’s response to any given increase of carbon dioxide will become smaller as the overall concentration of carbon dioxide increases with time. In mathematical parlance, the response is roughly ‘logarithmic’. The situation is a bit similar to adding more and more blankets in an effort to keep warm. The more blankets you have, the less will be the effect of one extra. An economic analogy might be the law of diminishing returns.
As any student of mathematics will tell you, an ‘exponential’ increase of something which imposes a ‘logarithmic’ change on something else means that, while that something else may continue to change, it will not change faster and faster.
Translated into plain English, if one really believes in doing something expensive about limiting climate change, there is probably no great reason for doing it now. Adaption to climate change in the future will be just as easy (or as difficult) as would be adaption now. One might as well put off the panic until it becomes observationally obvious that any change in climate resulting from human use of fossil fuels is both significant and detrimental.
It may be that people of the future decide in their time that it is indeed worthwhile reducing atmospheric carbon dioxide by limiting carbon emissions. It might be a bigger job by then, but it would probably be a lot cheaper. It would certainly be a lot cheaper from the point of view of those of the present generation who apply a normal discount for the future.