Not Spaghetti

Agreed, Arthur. Actually, there is more to this than a few competing forecasts.

In the year 2000 Hansens’ famous “B” (business as usual) and “C” (capped CO2 emissions) were about the same at +0.5 degrees C relative to the 1951 – 1980 base line.

Thereafter the lines diverged, because CO2 emissions continued to increase while temperatures did not change.

Reading from the graph at RC, (their latest updates) by 2009 the figures were as follows:

Actual GISS 0.57
“B” Line 0.89
“C” Line 0.60

If the actual trend continues, and temperatures do not rise, by 2013 the “C” line and the GISS actuals will be close at about 0.55 degrees C, and the “B” to “C” divergence will be 0.5 degrees C.

At that point it will be very difficult to use the AGW theory to justify expensive attempts to curtail CO2 emissions.