the long run (albeit at a higher average temperature than today’s), the
atmospheric concentration of greenhouse gases must also be stabilized, at
least eventually. Such stabilization will eventually require an enormous
cut in the annual flow of GHG emissions from its current level of 50
billion tonnes of to about 5 billion tonnes per year, the amount
Earth can naturally absorb annually. Such a reduction in the annual flow
of global GHG emissions is an enormous task and will take many years to
accomplish.
CO 2 e