Human and natural fertility

I have just found at Spiked Online Brendan O'Neill's superb recent essay on whether the earth is finite, and I heartily recommend it. Here's a sample:

Over the past 200 years, Malthusians have tended to look at people as simply the users-up of scarce resources. They have tended to view nature as the producer of things and mankind as the consumer of things. And their view of people as little more than consumers - almost as parasites - inevitably leads to them seeing human beings as the cause of every modern ill, and therefore reducing the number of human beings as the solution to every modern ill. Their focus on finiteness means they conceive of humanity as a kind of bovine force, hoovering up everything that it comes across.

I read this while sitting in a hotel room at San Francisco airport. Huge jets queue for take off in full view of my window. I am in the middle of a great conurbation. But between me and the jets lies a stretch of water, an arm of the Bay itself. And the water is a bird watcher's paradise. There are rafts of ducks such as buffleheads and wigeon. There are pelicans, grebes and two speces of gull. Along the shore there are great white and little egrets, willets, whimbrels, grey plovers, stints, dowitchers, avocets, yellow-legs and tight flocks of sandpipers. Sea lions cruise a litle further out, and an osprey has just plunged into the water after a fish.

My point? The water is presumably `polluted' by humankind with nitrogen and phosphorus from farming and sewage run-off, or `enriched' as it is sometimes called. Without people I doubt these would be nearly as much birdlife here. People enhance the productivity of natural ecosystems as well as agricultural ones.