Leading Climate Scientist admits climate models are bollox

[NickFitz]

In what way?

The models exaggerate global warming is the point.

Can you explain how the above statement contradicts it?

Actually, your point appears to be "Leading Climate Scientist admits climate models are bollox" yet the paper cited (not the ignoramus's blog post referring to the paper) merely makes the blindingly obvious point that models are, by definition, incomplete representations of reality, which can however be improved and supplemented by experimental observation:

"Climate models, based on physical laws that describe the structure and dynamics of the atmosphere and ocean, as well as processes on the land, have been developed to simulate climate. Models help us understand climate sensitivity, because we can change processes in the model one-by-one and study their interactions But if models were our only tool, climate sensitivity would always have large uncertainty. Models are imperfect and we will never be sure that they include all important processes. Fortunately, Earth's history provides a remarkably rich record of how our planet responded to climate forcings in the past. This record yields, by far, our most accurate assessment of climate sensitivity and climate feedbacks."

It also makes the point that, in many cases, one does not even need to use complex models but can use simpler techniques to calculate the effects of climate change; e.g.:

• "No climate model is needed to calculate the forcing due to changed greenhouse gas amount. It requires only summing over the planet the change of heat radiation to space, which depends on known atmospheric and surface properties."
  
  
• "We will employ these forcings for simplified calculations of global temperature, demonstrating that a simple Green's function calculation, with negligible computation time, yields practically the same global temperature change as the complex climate model, provided that the global model's 'climate response function' has been defined."
  
  
• "Calculation of the climate forcings due to the GHG and ice sheet changes is a radiative calculation; it does not require use of a global climate model. Clouds may differ in the LGM, but those changes are part of the fast-feedback being evaluated. The forcing calculation uses a climatologic distribution of clouds (obtained from observations, but the calculated forcing differs insignificantly if clouds instead are taken from a general circulation model; Hansen et al., 1984)."
  
  
• "Below we argue that the real world response function is faster than that of modelE-R. We also suggest that most global climate models are similarly too sluggish in their response to a climate forcing and that this has important implications for anticipated climate change."

However it still says that climate change is happening, and it is happening primarily as a consequence of human activity. The major problem he has with models, it turns out, is that empirically observable climate change is happening at a faster rate than many models predict.

[EternalOptimist]

not everyone sees it that way nick

"People underestimate the power of models. Observational evidence is not very useful, Our approach is not entirely emprical."

John Mitchell, chief research
scientist at the Met


“It doesn’t matter what is true, it only matters what people believe is true.”
- Paul Watson,
co-founder of Greenpeace

[pjclarke]

The paper is a draft, posted for comment and is rather good. It just doesn't say what whoever writes 'The Hockey Schtick' wants it to. (That would be front page news, given Hansen's reputation - he gets rock star reception at conferences, was awarded the highest honour of the American Met Society, defended the Kingsnorth protestors etc etc.).

The uncertainty in aerosol forcing is not new, this paper attempts a new estimate of the actual value and asserts that the modelled range is too small, the modelled range is -0.4 to -1.1 W/m2, while Hansen estimates a range -1.3 to -1.9. Both values are within the uncertainty range estimated by the IPCC, though. Move on, really not much to see here. The implications, however are described thus:

If the negative aerosol forcing is understated by as much as 0.7 W/m2, it means that aerosols have been counteracting half or more of the GHG forcing. In that event, humanity has made itself a Faustian bargain more dangerous than commonly supposed.

It's a wide-ranging paper though, and the abstract does not do it justice, anyone interested in the science should read it.

In other Hockey Stick news, a paper critical of the methods behind the original HS studies has been withdrawn due to dubious scholarship. Students of irony will appreciate the fact that this paper, which was critical of peer review standards and data retention policies in climate science, was accepted after just 6 days and that all paper and electronic copies of the review have gone missing .....

[EternalOptimist]

It is a draft, and the review of aerosols are, well, about time. maybe clouds next eh ?

but no matter how you spin it pj, even in your wildest dreams, even saint Hansen himself

cannot claim that the science is settled.

[pjclarke]

even saint Hansen himself cannot claim that the science is settled.

False binary. There are not two classes of science, settled and not settled. That's a politician's rather than a scientist's soundbite. I've never said that, and far as I know, nor has Hansen.

[EternalOptimist]

False binary. There are not two classes of science, settled and not settled. That's a politician's rather than a scientist's soundbite. I've never said that, and far as I know, nor has Hansen.

but it's what you have been teaching our kids

[pjclarke]

One thing thats always puzzled me, is why the big emphasis on the atmospheric temperature ? ... Surely its the heat content of the oceans that we should be looking at ?

Absolutely. That is a far better metric. here 'tis:-



Source:- Lyman et al

[EternalOptimist]

now we all know that models are flakey. so stop it with the models.
the best way to measure ocean heat content is via thermal expansion which equates to sea level rise

what does Hansen have to say about sea level rises ? say in Manhatten for example

[pjclarke]

All models are wrong by definition. Some models are useful. Besides, the best way to measure heat is via temperature using thermometers which, if you read the paper is what Lyman (the black line) did.

I know the Hansen quote you're referring to and it really does expose the desparation in some quarters. Rather than engage with his peer-reviewed research we must focus instead on a press interview from 2001 with Rob Reiss:-

While doing research 12 or 13 years ago, I met Jim Hansen, the scientist who in 1988 predicted the greenhouse effect before Congress. I went over to the window with him and looked out on Broadway in New York City and said, “If what you’re saying about the greenhouse effect is true, is anything going to look different down there in 20 years?” He looked for a while and was quiet and didn’t say anything for a couple seconds. Then he said, “Well, there will be more traffic.” I, of course, didn’t think he heard the question right. Then he explained, “The West Side Highway will be under water"

The fact that the highway is still high and dry is used to brand Hansen alarmist. WattsUpWiththat even went to the trouble of surveying it using Google Earth . But even this attack based on decades old hearsay fails. Because:-

- The reporter was mistaken. Hansen said 40 years not 20.

- The highway he was referring to was temporary and has been rebuilt. The original suffered from flooding.

Monbiot said it best,

It is hard to convey just how selective you have to be to dismiss the evidence for climate change. You must climb over a mountain of evidence to pick up a crumb: a crumb which then disintegrates in your palm. You must ignore an entire canon of science, the statements of the world’s most eminent scientific institutions, and thousands of papers published in the foremost scientific journals.

Junk Science.

[BlasterBates]

Musings of a young climate scientist

Must be hard when you discover you've spent several years learning nonsense.