I am old enough to remember how around 1970 Americans like Paul Ehrlich were telling us quite clearly that by the year 2000 there wouldn't be enough food to eat or air to breathe on the planet.
The latest scare, of course, has been man-made global warming. Governments appeared to fall for it. Unfortunately for the environmentalists, the arguments in its favour appear to be losing their potency. The BBC now says that for the last 11 years there has not been any increase in global temperatures. Over the past 11 years, in fact, I believe global temperatures have dropped.
More and more people have begun to see that there is no concrete evidence for man-made global warming, to the extent that environmentalists are no longer talking about global warming, but about climate change. Climate change, of course, includes not only global warming, but global cooling.
An attendee at an environmental conference recently complained that in any other sphere, people wanted to see independent verification of scientific findings; but if environmental organisers said something, it was taken as gospel.
What he wanted to see, he said, was journalists treating "big environmentalism" the same way they treated big politics, big government and big business. By asking the same questions. Like where's the money coming from to promote all this about man-made global warming? And who's channelling it?
Now there are some interesting questions. . .