'Hansen has been wrong before'

How to Talk to a Climate Skeptic

Posted by Coby Beck (Guest Contributor) at 10:01 AM on 14 Dec 2006

(Part of the How to Talk to a Global Warming Skeptic guide)

Objection: In 1988, Hansen predicted dire warming over the next decade -- and he was off by 300%. Why in the world should we listen to the same doom and gloom from him today?

Answer: While in some instances it is ignorant repetition of misinformation, at its source this story is a plain lie.

In 1988, James Hansen testified before the U.S. Senate on the danger of anthropogenic global warming. During that testimony he presented a graph -- part of a paper published soon after. This graph had three lines on it, representing three scenarios based on three projections of future emissions and volcanism.

Hansen graph

Line A was a temperature trend prediction based on rapid emissions growth and no large volcanic event; it was a steep climb through the year 2000 and beyond.

Line B was based on modest emissions growth and one large volcanic eruption in the mid 1990s.

Line C began along the same trajectory as Line B, and included the same volcanic eruption, but showed reductions in the growth of CO2 emission by the turn of the century -- the result of hypothetical government controls.

As it happens, since Hansen's testimony, emissions have grown at a modest rate and Mt. Pinatubo did in fact erupt, though in the early 1990s, not the middle. In other words, the Line B forcings scenario came remarkably close to predicting what actually came to pass.

Not coincidentally, the observed temperature trend has tracked closely with the Line B prediction as well.

Hansen was right on the money, and the models he used proved successful.

Unfortunately, when Patrick Michaels made his testimony before Congress in 1998, ten years later, he saw fit to erase the two lower lines, B and C, and show the Senators only Line A. He did so to make his testimony that Hansen's predictions had been off by 300% believable. He lied by omission. This lie was picked up by Michael Crichton in his novel State of Fear (one of many omissions, confusions, and falsehood in that book -- see here).

To my knowledge, Patrick Michaels has never owned up to his deception, either with an apology and retraction or with an explanation, and consequently the urban myth lives on to this day.

RabettRun has some more detail and illustrations here.

For story: 'Hansen has been wrong before'
12 Comments | Post a Comment

It was not unfortunate

Michaels actions were deliberate and dishonest.

by EliRabett at 6:35 PM on 16 Dec 2006

no argument here

Yes, deliberate and dishonest. And unfortunate for the truth.

"What if this weren't a hypothetical question?" -- unknown

by Coby Beck at 11:04 PM on 16 Dec 2006

Heh

Both Michaels.

-David Ahlport

by GreyFlcn at 1:01 AM on 11 Apr 2007
[ Parent ]

No but, yes but...

I think the argument I read once (on SciGuy) was that even if this graph is right Hansen was going all over Washington with a different graph only showing the worst case scenario. Only at this testimony did he produce the full version.

In other words Hansen is supposed to be a liar too cowardly to lie at a Congressional testimony and therefore the fact that he was right on the mark with his prediction is irrelevant. Or something like it. I'm still to really comprehend the thinking these people use.

by MarkUK at 6:12 AM on 11 Apr 2007

interesting logic!

Hi MarkUK,

Ok, I see what they are saying. Hansen is too cowardly to lie to a Senate hearing, whereas Patrick Michaels isn't! So we obviously should put our trust more in Michaels...or something.

"What if this weren't a hypothetical question?" -- unknown

by Coby Beck at 7:09 PM on 12 Apr 2007
[ Parent ]

There's

There's a really good comparison of the charts over here:

http://www.logicalscience.com/skeptic_arguments/models-do ...

As Hansen said when he presented it. Scenario B was most likely.

And guess what, scenario B is tracking almost perfectly. (And he gave this thing way back in 1989)

-David Ahlport

by GreyFlcn at 8:20 PM on 12 Apr 2007

wups.

Heh, well he showed it in congress in 1998.

But he was talking about it since 1989
http://greyfalcon.net/lindzen2.png

^ Vintage stuff. Still current ;D

(Note how it's published in "American Tobacco Magazine")

-David Ahlport

by GreyFlcn at 8:25 PM on 12 Apr 2007

What exactly are emissions ?

>> He lied by omission >>
Classic establishment tactics

Hansen is from NASA

I wonder what was the make up of what he termed "emissions".

This point may be the most critical point in his estimations.

by Zarkov at 11:51 PM on 12 Apr 2007

just check

zarkov,

instead of making sinister insunuations, why don't you just click the references and find out? Hansen's papers and the GISS climate models address all of the major climate forcings: CO2, CH4, NO2, ozone (stratosperic and tropospheric), solar irradiance, volcanic SO2, anthro aerosols, albedo changes and many others.

"What if this weren't a hypothetical question?" -- unknown

by Coby Beck at 2:07 AM on 15 Apr 2007

Very interesting

I could see BOTH men lying, especially while trapsing about Washington. When in Rome... Although lying is wrong, it doesn't make their science wrong.

by Bengt Washburn at 2:18 PM on 06 Nov 2007

Hansen's own words

From the 1988 Congressional record (EMPHASIS MINE):

Hansen: "We have considered several scenarios because there are uncertainties in the exact trace gas growth in the past and especially in the future. We have considered cases ranging from BUSINESS AS USUAL, WHICH IS SCENARIO A, to draconian emission cuts, scenario C, which would totally eliminate net trace gas growth by the year 2000."

He certainly opened himself up for the interpretation that he preferred scenerio A, given the low probability there would be any emissions changes.

by wmanny at 6:52 AM on 06 May 2008

Hansen Scenarios vs. Observed

There is no longer the need to chart Hansen's predictions, even his retroactively preferred Scenario B, against observed temperatures conveniently ending in 1998. It is now 2008, and none of Hansen's scenarios have been accurate for ten years. He is now warning us about a potential SIX degree upward move. Perhaps, just perhaps, the man has an agenda.

by wmanny at 11:07 AM on 07 May 2008

ADVERTISING POLICY

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