Step by step: Peter Singer 'A Fair Deal on Climate Change

from Project Syndicate

1. Establish the total amount of greenhouse gases that we can allow to be emitted without causing the earth’s average temperature to rise more than two degrees Celsius (3.6 degrees Fahrenheit), the point beyond which climate change could become extremely dangerous.
2. Divide that total by the world’s population, thus calculating what each person’s share of the total is.
3. Allocate to each country a greenhouse gas emissions quota equal to the country’s population, multiplied by the per person share.
4. Finally, allow countries that need a higher quota to buy it from those that emit less than their quota.

Seems perfectly reasonable to me.