Why can’t we stop Global Warming now?
I have several times been asked this question. There are, in essence, two answers. Both include within their explanation the passage of time. Nothing happens in zero time. Everything has its natural rhythm and changing that is always difficult and often impossible.
The first answer is that social systems have their own responses in time. The structure of our politics, religious mores, education, government, mining, manufacturing and the financial system each need time to respond to changing circumstances. Let us take just one fairly simple example. Let us assume that everyone on earth agreed that big cars are causing global warming and should not longer be used. This, of course, will not happen, but let us assume it does. Thousands of people have just invested a substantial lump of future income in a new car. They expect their car to last at least three years before they will be in a position to change it. There thus has to be at least a three-year time lag before any significant benefit will start to accrue.
All systems have such time lags and they are often cumulative. It is not the slightest use stamping your feet and saying you want it now. That is impossible. Accept it.
The second answer is that the natural systems that control the atmosphere and biosphere also have their natural time based responses. The vast majority of systems in the universe have these lags and their fundamental characteristic is called a time constant. They respond to a disturbance in a fashion that can be explained by invoking a time delay. The concept is identical in principal to the physicists’ half-life in the decay of radioactive elements. The accountants call a similar phenomenon the law of diminishing returns. Engineers call it a time constant and it is the time in which a system will respond to around two-thirds of the demand made upon it by a disturbance.
The demand we are making upon the earth is by inputting a step change in carbon dioxide. The atmosphere has been going its own way for about four billion years with inputs from many sources such as volcanoes, meteors and a multitude of life forms. In each case the atmosphere has responded. In at least five cases we know the response has caused major extinctions. It has taken man about one hundred and fifty years to make the step input of carbon dioxide. I call it a step input because one hundred and fifty years is a miniscule time in comparison to the age of the atmosphere or even to the thousands of years it has existed in more or less its current condition.
Once a step input is made it cannot be undone. Even if carbon dioxide production could be reduced to zero now, the damage is still done. The earth will respond to the existing step change in carbon dioxide levels. Just how, or when, it will respond is impossible to say. There are hundreds or even thousands of chemical reactions in the air, sea, land, life-forms, weather and rocks of the earth and many are intimately interconnected. Some will respond quite quickly, possibly in days, many in months or years. Others, we know, will respond in millions of years. The system is so complicated that the finest supercomputers we have could not possibly be programmed to simulate it. We shall never know all the details of what we have done. We will suffer the consequences on our own hides.
We are conducting a fairly hefty experiment on the atmosphere that is our only possible home and we have no way whatsoever of predicting the nature, magnitude or timing of the consequences. We do know that they cannot be reversed. That is why we cannot change global warming now. It is impossible. Kyoto? Meaningless Twaddle. Forget it.