Hansen’s 1988 appearance before a Senate committee conventionally marks the beginning of the era for climate alarm, when many Americans started worrying about global warming and why their leaders were doing so little about it.
This process is already embedded in conventional modeling of our climate future.
But the uncertainty range is much higher for aerosol cooling than for other, more widely measured climate inputs, and the high end of that estimated range is above a full degree of cooling.
In the “Pipeline” paper, Hansen gives a higher estimate still: that aerosols are cooling the planet by perhaps 1.5 degrees Celsius.
assumes and that a collapse of one of the ocean’s major circulation systems is possible this century, much sooner than most believe.
Persons:
wonks, Hansen
Organizations:
NASA, United Nations