Is a Picture Worth a Trillion Dollars?

Updated with GISS Global Temperature and the Charney estimates at bottom:

Once the minions of the Great and Power Carbon spread their faith to the economic community, the finest Economists the world has to offer discuss the discount rate that should be justified for saving the world from the greatest peril current rattling around in the minds of the minions.  If "sensitivity" is greater than 3C it will cost trillions of US dollars to save the world, over $30 per ton of Carbon must be charged.  If "Sensitivity" is approximately 1.6 C, the world can eke by on a measly trillion or so with Carbon taxed at about $3 per ton.  If "Sensitivity" is less than 1, the whole Great and Powerful Carbon Crisis should have never existed.

When BEST first published their land only temperature reconstruction they included a simple forcing fit.  Volcanic and CO2 forcing scaled to produce a simple fit to the land only data.  You can download the data for their fit from their quickly improving website.  Above are three "Sensitivities with the volcanic forcing on a 1985 to 1995 baseline so later, satellite era data can be used.

Using the NOAA ERSST3 tropical ocean data (20S-20N) with the same baseline, this is the fit for three "Sensitivites"  Green nada cash, Red a trillion dollars maybe and Orange multiple trillions.  The 1.6C, trillion maybe is the best fit.

Using the same "sensitivities" without the volcanic for simplicity, back to 1700 AD, 1.6 a trillion maybe is still the best fit but OMG trillions is coming on strong!

Starting at 900 AD, 1.6 C a trillion is still the best fit but nada, zilch, bagels 0.8C is making a showing, OMG TRILLIONS is falling back in the pack.

 Starting at 0 AD, nada, zilch, bagels, 0.8C takes the lead for good.  The minions of the Great and Powerful Carbon can smooth out the past from 1500 AD back, but not even "Dimples" Marcott can get rid of the dip near 1700 AD, the period formerly known as the little ice age.  So the next time someone says they have to collect taxes for the Great and Powerful Carbon, stick this in their ear. 

 Since everyone seems to have favorite data to use, this one compares GISS temperature with the two original estimates offered to Jules Charney in 1979, Hansen 4C and Manabe 2C.  The 0.8 C, my estiamte for the more realistic lower end is also included.  The 3C mean IPCC estimate is the average of the Hansen and Manabe estimates with an uncertain to 0.5 C on both ends producing the original 1.5 to 4.5 C sensitivity range.  The baseline is still 1985 to 1995 which is roughly the "initial" condition for the first IPCC report.  Manabe's 2 C is right on time with the 0.8 providing a reasonable lower bound and the 4C still in the hunt but showing signs of divergence based on the 1990 start date.  Hinecasting, the 4C wanders out of contention with both 0.8C and 2C maintaining contact with the instrumental.   Just in case you were curious.