Importance of Hansen’s Models

Chris O’Neill said on Deltiod

Gee, and I thought that twenty year old model was the be-all and end-all of climate forecasting.

My respnose was:

Chris, Hansen’s 20-yer old models presented in #109 are very important. They  are the  cornerstone of IPCC/your government policy. If they are wrong then your government is going the wrong way on CO2.

Yet in 2006 Hansen said here that Scenario B “was dead on the money”. It would now appear that he was wrong. Planet Earth appears to be tracking below the zero-emmissions Scenario C and Scenario B is not “dead on the money”; it is way too high.

GISS Temperature Data January-June 2008

Eli Rabbett re #192 on Deltioid wrote that

“This is the one with January standing for all of 2008”.

My response to Eli was that I stated that the temperature figures were for the first six months of the year. You can check the GISS surface station figures here or the land ocean data here.

I summarise the GISS Jan-Jun 2008 figures below for ease of reference:

GISS Temperature Data 

2008      Land       Land-
         Stations      Ocean

Jan               35             14
Feb               32             25
Mar               72             60
Apr               52             42
May              45             39
Jun               26             26
Average = 44           34


  1. Surface Station Data Jan-Jun 2008 average = 0.44 °C.
  2. Land-Ocean Data Jan-Jun 2008 average = 0.34 °C.

The latest figures are well below my original Jan-May graph posted in Deltoid #190. It is evident from my graph, and the latest GISS figures, that the 2008 temperatures will be significantly below recent temperatures. They will probably be as low as 1995 or even, God forbid, 1990! It would appear that our planet is currently tracking below Hansen’s Zero-Emissions Scenario C. Good old planet Earth!

I reiterate, is it possible that a stabilisation of temperatures and/or global cooling, as predicted by the solar-cycle/cosmic-ray fraternity, is beginning to happen?

Eli, I look forward to your response.

Reliability of Hansen’s Climate Change Models

It would appear that Hansen’s 1988 climate models are beginning to diverge from the actual temperature observations

The latest GISS readings are shown in the diagram below:

Scenarios A, B and C Compared with Measured GISS Surface Station and Land-Ocean Temperature Data
Scenarios A, B and C Compared with Measured GISS Surface Station and Land-Ocean Temperature Data

The original diagram can be found in Fig 2 of Hansen (2006) and the latest temperature data can be obtained from GISS. The red line in the diagram denotes the Surface Station data and the black line the Land-Ocean data. My estimate for 2008 is based on the first six months of the year.

Scenarios A and C are upper and lower bounds. Scenario A is “on the high side of reality” with an exponential increase in emissions. Scenario C has “a drastic curtailment of emissions”, with no increase in emissions after 2000. Scenario B is described as “most plausible” and closest to reality.

Hansen (2006) states that the best temperature data for comparison with climate models is probably somewhere between the Surface Station data and the Land-Ocean data. A good agreement between Hansen’s premise and measured data is evident for the period from 1988 to circa 2005; especially if the 1998 El Nino is ignored and the hypothetical volcanic eruption in 1995, assumed in Scenarios B and C, were moved to 1991 when the actual Mount Pinatubo eruption occurred.

However, the post-2005 temperature trend is below the zero-emissions Scenario C and it is apparent that a drastic increase in global temperature would be required in 2009 and 2010 for there to be a return to the “Most-Plausible” Scenario B.

Will global warming resume in 2009-2010, as predicted by the CO2 forcing paradigm, or will there be a stabilsation of temperatures and/or global cooling, as predicted by the solar-cycle/cosmic-ray fraternity?

Watch this space!

P.S: It would be very interesting to run an “Actual Emissions” Scenario on the Hansen model to compare it with actual measurements. The only comments that I can glean from a literature survey is that Scenario B is closest to reality, but it would appear that CO2 measurements are above this scenario, but unexpectedly, methane emissions are significantly below. Does anyone have the source code and/or input data to enable this run?