Growing numbers of people and their increasing consumption mean fewer resources for wild plants and animals: less land, less water, and changes in the climates they evolved in. Extinctions are rippling through the 30 million species thought to exist (about 2 million of which have been identified).
It is not just the destruction of habitat – land, oceans, lakes and rivers – but also the moving of plants and animals; these invasive species become causes of extinctions. More important than individual species are the networks – the ecosystems – that support them, support life on earth, and provide us with food, water, topsoil and fibres. The most complex ecosystems containing the greatest species diversity tend to be in the tropics, where nations are poorer and populations are growing fastest.
It is impossible to put a monetary value on ecosystem services such as forests’ and oceans’ ability to lock up carbon and keep it out of the atmosphere, but when scientists try, they come up with figures far larger than global economies. This truth ought to help us figure ecosystem services into our financial and economic planning, budgeting far more for investments in conservation, investments that will begin to pay off immediately and will be ever more important to larger, future generations.
