We've heard that the world's wealthiest 10 percent are disproportionately responsible for environmental damage.

It’s difficult to put a price on the environment, and some scientists even argue it’s beside the point: that nature has intrinsic value, beyond the services it provides to us.

But in some situations, it helps to try to put it in economic terms: especially when those are the terms the world’s wealthiest are used to dealing in.