Classic Podium: The fragility of our life on earth

From a speech on the environment by Prime Minister, Margaret Thatcher, to the General Assembly of the United Nations, New York (8 NOVEMBER, 1989)

DURING HIS historic voyage through the South Seas on the Beagle, Charles Darwin landed one morning in 1833 on the shore of Tahiti. After breakfast, he climbed a nearby hill to survey the surrounding Pacific. The sight seemed to him like "a framed engraving", with blue sky, blue lagoon, and white breakers crashing against the encircling coral reef. As he looked out, he began to form his theory of the evolution of coral; 154 years after Darwin's visit to Tahiti we have added little to what he discovered.

What if Charles Darwin had been able not just to climb a foothill, but to soar through the heavens in one of the orbiting space shuttles? What would he have learned as he surveyed our planet from that altitude?

As we travel through space, as we pass one dead planet after another, we look back on our earth, a speck of life in an infinite void. It is life itself, incomparably precious, that distinguishes us from the other planets.

Of course, major changes in the earth's climate and the environment have taken place in earlier centuries when the world's population was a fraction of its present size. The causes are to be found in nature itself. What we are now doing to the world, by degrading the land surfaces, polluting the waters, and adding greenhouse gases to the air at an unprecedented rate, is new.

We are seeing a vast increase in the amount of carbon dioxide reaching the atmosphere. The annual increase is three billion tonnes. We're seeing the destruction on a vast scale of tropical forests that are uniquely able to remove carbon dioxide from the air. The consequences of this become clearer when one remembers that tropical forests fix more than 10 times as much carbon as do forests in the temperate zones.

Put in its bluntest form, the main threat to our environment is more and more people, and their activities: the land they cultivate ever more intensively; the forests they cut down and burn; the mountain sides they lay bare; the fossil fuels they burn; the rivers and sky they pollute.

Change to the sea around us, change to the atmosphere above, leading in turn to change in the world's climate could alter the way we live in the most fundamental way of all. That prospect is a new factor. It is comparable in its implications to the discovery of how to split the atom. Indeed, its results could be even more far-reaching.

The problem of global climate change is one that affects us all and action will only be effective if it is taken at the international level. It is no good squabbling over who should pay. As well as the science, we need to get the economics right.

First, we must have economic growth to generate the wealth required to pay for the protection of the environment. But it must be growth that does not plunder the planet today and leave our children to deal with the consequences tomorrow. Second, we must resist the simplistic tendency to blame multi-national industry for the damage. Far from being the villains, it is on them that we rely to do research and find solutions.

I would make a plea for a further global convention, one to conserve the infinite variety of species - of plant and animal life - that inhabit our planet. The tropical forests contain a half of the species in the world, so their disappearance is doubly damaging. It is astonishing that our civilisation, whose imagination has reached the boundaries of the universe, does not know, to within a factor of 10, how many species the earth supports. What we do know is that we are losing them at a reckless rate.

Reason is humanity's special gift. Now we must use our reason to find a way in which we can live with nature, not dominate nature.