Chris,
It is difficult for me to tell whether you are simply misinformed or are purposely fabricating a story in defense of Hansen’s failed forecast.
The Hansen 1988 forecast to which I am referring is:
http://pubs.giss.nasa.gov/docs/1988/1988_Hansen_etal.pdf
Check Figure 3 (this is the graph, which I posted earlier – but will post again):
http://farm3.static.flickr.com/2537/5738998081_b3b3e55049_b.jpg
Hansen’s 1988 study stipulated:
Scenario A assumes that growth rates of trace gas emissions typical of the 1970s and 1980s will continue indefinitely; the assumed annual growth rate averages about 1.5% of current emissions, so that the net greenhouse forcing increases exponentially.
Scenario B has decreasing trace gas growth rates, such that the annual increase of the greenhouse climate forcing remains approximately constant at the present level.
Scenario C drastically reduces trace gas growth between 1990 and 2000 such that the greenhouse climate forcing ceases to increase after 2000.
Based on CDIAC data, the actual CO2 emission growth rate increased from 1.5% in the 1970s and 1980s to 1.7% from 1988 to today, so the actual rate of increase was actually around 13% greater than that assumed by Hansen for Scenario A.
http://cdiac.ornl.gov/ftp/ndp030/global.1751_2008.ems
Obviously, Scenarios B and C are way off the mark.
The problem is that Hansen’s Scenario A grossly overestimated the GH warming that would result, very likely because he used a climate sensitivity estimate that was high by a factor of 2 or more..
Actual warming turned out to be the same as Hansen’s Scenario C, based on the complete shut down of GHG emissions in 2000 ” such that the greenhouse climate forcing ceases to increase after 2000”. But this did not happen, did it?
You can wiggle and squirm all you want to Chris, but all-in-all it was a forecast that turned out to be grossly exaggerated (like all of Hansen’s “predictions”).
Max