Guess who said that?

...
It is of course true that none of us would be here but for the greenhouse effect. It gives us the moist atmosphere which sustains life on earth. We need the greenhouse effect—but only in the right proportions.

More than anything, our environment is threatened by the sheer numbers of people and the plants and animals which go with them... 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 the seas they pollute.

The result is that change in future is likely to be more fundamental and more widespread than anything we have known hitherto. Change to the sea around us, change to the atmosphere above, leading in turn to change in the world's climate, which could alter the way we live in the most fundamental way of all.

That prospect is a new factor in human affairs. It is comparable in its implications to the discovery of how to split the atom. Indeed, its results could be even more far-reaching.

But 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...

(Hint: the person has a pretty solid chemical science background.)