How close IS the Tipping Point?

In previous posts and in public statements (most recently on the BOCC's decision to site a waste transfer station), I have asserted that every decision government makes should factor in global warming and carbon emissions. Concerns over global warming should not be the only factor considered, but we should include energy use, energy efficiency, carbon emissions as criteria in all are critical decisions.

The reason is this: scientist believe earth may soon be reaching a tipping point when it comes to the effects of carbon on the atmosphere. We can no longer afford to dither. Action must be taken soon and by all of us: individuals, governments, and businesses.

This excellent article from USA TODAY explains why.