“The situation can be controlled and even reversed but it demands co-operation on a scale and intensity beyond anything achieved so far…I realise that there are any number of vital causes to be fought for, I sympathise with people who work up a passionate concern about the all too many examples of inhumanity, injustice, and unfairness, but behind all this hangs a really deadly cloud. Still largely unnoticed and unrecognised, the process of destroying our natural environment is gathering speed and momentum. If we fail to cope with this challenge, all the other problems will pale into insignificance.”

Edinburgh University Union (1969)
The Environmental Revolution: Speeches on Conservation, 1962–77 (1978)
Context: The sheer weight of numbers of the human population, our habitations, our machinery and our ruthless exploitation of the living and organic resources of the earth; together these are changing our whole environment. This is what we call progress and much of this development is naturally to the direct and welcome benefit of mankind. However, we cannot at the same time ignore the awkward consequences and the most direct and menacing, but not the only consequence of this change, is pollution... Pollution is a direct outcome of man's ruthless exploitation of the earth's resources. Experience shows that the growth of successful organic populations is eventually balanced by the destruction of its own habitat. The vast man-made deserts show that the human population started this process long ago. There are two important differences today. In the first place the process has gone from a walking pace to a breakneck gallop. Secondly we know exactly what is happening. If not exactly in all cases, we know enough to appreciate what is happening and the need to take care... Pollution is no longer a matter of local incidents, today it has the whole biosphere in its grip. The processes which devastated the Welsh valleys a hundred years ago are now at work, over, on and under the earth and the oceans. Even if we bury all this waste underground there still remains the risk that toxic materials through chemical reactions will be washed out and into underground water courses. If ever there was an area of research more closely related to human welfare it is the problem of the safe disposal of waste and effluents... The fact is that we have got to make a choice between human prosperity on the one hand and the total well-being of the planet Earth on the other. Even then it is hardly a choice because if we only look for human prosperity we shall certainly destroy by pollution the earth and the human population which has existed on it for millions of years... If the world pollution situation is not critical at the moment it is as certain as anything can be that the situation will become increasingly intolerable within a very short time. The situation can be controlled and even reversed but it demands co-operation on a scale and intensity beyond anything achieved so far... I realise that there are any number of vital causes to be fought for, I sympathise with people who work up a passionate concern about the all too many examples of inhumanity, injustice, and unfairness, but behind all this hangs a really deadly cloud. Still largely unnoticed and unrecognised, the process of destroying our natural environment is gathering speed and momentum. If we fail to cope with this challenge, all the other problems will pale into insignificance.