My presentation today is exactly 20 years after my 23 June 1988 testimony to Congress, which alerted the public that global warming was underway. There are striking similarities between then and now, but one big difference.
Again a wide gap has developed between what is understood about global warming by the relevant scientific community and what is known by policymakers and the public.
Now, as then, frank assessment of scientific data yields conclusions that are shocking to the body politic. Now, as then, I can assert that these conclusions have a certainty exceeding 99 percent.
The difference is that now we have used up all slack in the schedule for actions needed to defuse the global warming time bomb. The next President and Congress must define a course next year in which the United States exerts leadership commensurate with our responsibility for the present dangerous situation.
Update: The usual noise (sort of like sci.environment about ten years ago) appears on today's discussion of this presentation on Dot Earth. I'm particularly taken by this comment #129:
My understanding of economics is quite complete, thank you, as is my understanding of the power of freedom, and the proven consequences of totalitarianism.
What is most disturbing is that AGW’s supporters understanding of economics is so weak, that they don’t recognize government force and intervention when it’s staring them in the face.
The whole underpinning of a carbon-tax, ignoring the whatever scientific basis it may or may not have, is government force. ...
I really appreciate the claim of "complete understanding". It is nice to know that economics is so trivial that a claim of "complete understanding" can be made without supporting evidence.
Unfortunately, all the usual patterns are reinforced in the Dot Earth discussion, and the stalemate continues.
Hansen's point, though, is that we can't afford a stalemate anymore.