Engineering and scientific advance have given us transport by land and air, the capacity and need to exploit fossil fuels which had lain unused for millions of years. One result is a vast increase in carbon dioxide. And this has happened just when great tracts of forests which help to absorb it have been cut down.
For generations, we have assumed that the efforts of mankind would leave the fundamental equilibrium of the world's systems and atmosphere stable. But it is possible that with all these enormous changes (population, agricultural, use of fossil fuels) concentrated into such a short period of time, we have unwittingly begun a massive experiment with the system of this planet itself.
Recently three changes in atmospheric chemistry have become familiar subjects of concern. The first is the increase in the greenhouse gases—carbon dioxide, methane, and chlorofluorocarbons—which has led some to fear that we are creating a global heat trap which could lead to climatic instability. We are told that a warming effect of 1°C per decade would greatly exceed the capacity of our natural habitat to cope. Such warming could cause accelerated melting of glacial ice and a consequent increase in the sea level of several feet over the next century.
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It is noteworthy that the five warmest years in a century of records have all been in the 1980s
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In studying the system of the earth and its atmosphere we have no laboratory in which to carry out controlled experiments. We have to rely on observations of natural systems. We need to identify particular areas of research which will help to establish cause and effect. We need to consider in more detail the likely effects of change within precise timescales. And to consider the wider implications for policy—for energy production, for fuel efficiency, for reforestation. This is no small task, for the annual increase in atmospheric carbon dioxide alone is of the order of three billion tonnes. And half the carbon emitted since the Industrial Revolution remains in the atmosphere. We have an extensive research programme at our meteorological office and we provide one of the world's four centres for the study of climatic change. We must ensure that what we do is founded on good science to establish cause and effect.
In the past when we have identified forms of pollution, we have shown our capacity to act effectively. The great London Smogs are now only a nightmare of the past. We have cut airborne lead by 50 per cent. We are spending £4 billion on cleansing the Mersey Basin alone; and the Thames now has the cleanest metropolitan estuary in the world. Even though this kind of action may cost a lot, I believe it to be money well and necessarily spent because the health of the economy and the health of our environment are totally dependent upon each other.