If you don't wish to take my word on Malthus, here's a snippet from Econlib's excellent encyclopedia entry that I've just stumbled upon:
Malthus is arguably the most misunderstood and misrepresented economist of all time. The adjective “Malthusian” is used today to describe a pessimistic prediction of the lock-step demise of a humanity doomed to starvation via overpopulation. When his hypothesis was first stated in his best-selling An Essay on the Principle of Population (1798), the uproar it caused among noneconomists overshadowed the instant respect it inspired among his fellow economists. So irrefutable and simple was his illustrative side-by-side comparison of an arithmetic and a geometric series — food increases more slowly than population — that it was often taken out of context and highlighted as his main observation. The observation is, indeed, so stark that it is still easy to lose sight of Malthus’s actual conclusion: that because humans have not all starved, economic choices must be at work, and it is the job of an economist to study those choices.Need I remind you, Econlib is a libertarian initiative, so it's not like this is grandstanding from some left-leaning environmental institute.