Climate Sensitivity Lower than Previously Claimed

[TimG]

There is is new paper in Nature Geoscience that confirms what skeptics have been saying for years:

The models overestimate climate sensitivity.

First, using what is probably the most robust method available, it establishes a well-constrained best estimate for TCR that is nearly 30% below the CMIP5 multimodel mean TCR of 1.8°C (per Forster et al. (2013), here). The 95% confidence bound for the Nature Geoscience paper's 1.3°C TCR best estimate indicates some of the highest-response general circulation models (GCMs) have TCRs that are inconsistent with recent observed changes. Some two-thirds of the CMIP5 models analysed in Forster et. al (2013) have TCRs that lie above the top of the 'likely' range for that best estimate, and all the CMIP5 models analysed have an ECS that exceeds the Nature Geoscience paper's 2.0°C best estimate of ECS.

Of course, this is not news for people that actually looked at the data over the last 10 years and did not have a vested interest in the AGW industry.

The alarmist spin is amusing:

http://www.newscientist.com/article/dn23565-a-second-chance-to-save-the-climate.html

Humanity has a second chance to stop dangerous climate change. Temperature data from the last decade offers an unexpected opportunity to stay below the agreed international target of 2 °C of global warming.

So the previous models exaggerated warming but this is should be taken as an opportunity to re-introduce ineffective anti-CO2 policies?????

Talk about Chutzpah.

I realize that the alarmist apologists will insist this is self correcting science at work (a point I concede) but that does not excuse the vitriol hurled at people who looked at the data and raised questions over the last few years. Science is never settled.

More info here:

http://judithcurry.com/2013/05/19/mainstreaming-ecs-2-c/

Edited May 20, 2013 by TimG

[eyeball]

A second chance to save the climate

Yeah, good luck with that.

[bush_cheney2004]

More info here:

http://judithcurry.com/2013/05/19/mainstreaming-ecs-2-c/

Good stuff....with a refreshing self indictment by a "climate scientist" for wasted energies compared to useful and applied research (Donald Stokes' so called Pasteur's Quadrant), as referenced by Judith Curry (Georgia Tech):

...With regards to climate science, the concern that I have is that there is too much research in the lower half of Stokes’ diagram, scoring low on making advances to fundamental understanding. Applied research that is useful and used is a good thing, but at the end of the day I don’t see all that much applied climate research actually getting used by decision makers. The primary problem being that there is too much focus on the climate models, and the climate models are not yet up to the task.

Edited May 20, 2013 by bush_cheney2004

[ReeferMadness]

It doesn't surprise me in the least that climate models are not that accurate. The science is complex and relatively new. Models often have to go through a 'trial-and-error' cycle before they get perfected. But conclusion can be drawn from this? If the model can be wrong in one direction now, it could just as easily be wrong in the other direction later. The climate is not a linear system. There is no assurance that once changes start, we will be able to do anything to change them before they have catastophic consequences. This is what scientists have been trying to tell us.

But too many people only understand that it will just make the gas for their garden tractors and 4x4s more expensive.

Sadly, it also doesn't surprise me that many would seize upon this as an excuse to continue to change the composition of our one and only atmosphere. Devotion to economic doctrine is a belief system. It's more religion than science.

The only thing that really surprises me is that our species has survived as long as it has. Contrary to popular belief, it definitely isn't due to average intelligence.

Edited May 20, 2013 by ReeferMadness

[TimG]

But too many people only understand that it will just make the gas for their garden tractors and 4x4s more expensive.

Too many people don't understand how much our society depends on the cheap and reliable energy that comes from fossil fuels. Eliminating fossil fuels is simply not an option and any policy based on that objective is a failure before it starts. The only reason some people insist on useless anti-CO2 policies is because these policies promote their ideological objectives which are unrelated to CO2. It is more a religion than a science.

Sadly, it also doesn't surprise me that many would seize upon this as an excuse to continue to change the composition of our one and only atmosphere.

Sadly, there is no evidence that the AGW industry will acknowledge that their preferred policies cannot work and dumping more money into them makes even less sense given the relatively slow rate of warming. We would be much better off figuring out how to adapt. Edited May 20, 2013 by TimG

[waldo]

It doesn't surprise me in the least that climate models are not that accurate. The science is complex and relatively new. Models often have to go through a 'trial-and-error' cycle before they get perfected. But conclusion can be drawn from this? If the model can be wrong in one direction now, it could just as easily be wrong in the other direction later. The climate is not a linear system. There is no assurance that once changes start, we will be able to do anything to change them before they have catastophic consequences. This is what scientists have been trying to tell us.

what conclusions can be drawn? Several:

- as is MLW member, 'TimG's', manner, he'll flaunt any single study that he presumes to champion his cause. There are many other recent studies that bring forward sensitivity results that fall within the IPCC AR4 estimate range. As a single study, is it particularly noteworthy?

- the ECSensitivity for the study comes in at 2.2 (1.4 - 4.0) @ 5-95% confidence intervals. Your point about, "shifting direction... climate is not a linear system', is most astute. This study emphasizes the last decade observations; a period where warming has been at a reduced rate as compared to earlier decades. Were the higher sensitivity results prior to the last decade wrong... and this study is now the definitive 'right' result? There's a significant research effort engaged in analyzing the reduced warming rate over recent years... understanding natural influences, perhaps unique to this last decade... ocean heating and heat storage, etc.

- the study only factors the influence of fast feedbacks (like sea ice, water vapour), not the most significant and concerning longer-term feedback influences (like ice sheets, GHG release from soils/tundra/ocean, etc)

- the study is limited to recent observational temperature and doesn't include/factor paleoclimatic data. If MLW member, 'TimG', wants to argue for lower climate sensitivity than he must account for the wide temperature fluctuations seen throughout history.

- fake-skeptics seem very quick to adopt this study... yet discount the many statements from an assortment of its authors that suggest the study results aren't inconsistent with previous study estimates (i.e., with the accepted IPCC range of estimates).

- and most significant of all, it appears MLW member, 'TimG', perhaps purposely, confuses sensitivity with actual warming! Sensitivity is but one of 3 factors that will determine the actual amount of warming:

- EQSensitivity

- CO₂ ppm concentration levels in the atmosphere

- longer-term feedback influences

[ReeferMadness]

Too many people don't understand how much our society depends on the cheap and reliable energy that comes from fossil fuels. Eliminating fossil fuels is simply not an option and any policy based on that objective is a failure before it starts. The only reason some people insist on useless anti-CO2 policies is because these policies promote their ideological objectives which are unrelated to CO2. It is more a religion than a science.

Sadly, there is no evidence that the AGW industry will acknowledge that their preferred policies cannot work and dumping more money into them makes even less sense given the relatively slow rate of warming. We would be much better off figuring out how to adapt.

Yes, we have a dependency on fossil fuels, like we have a dependency on economic growth. Much like an addict has a dependency on crack. The growth can't last forever - neither can the fossil fuels. The only question is whether people will learn to acknowledge environmental limits before we destroy ourselves.

Clearly, you are a lost cause.

[TimG]

Yes, we have a dependency on fossil fuels, like we have a dependency on economic growth.

We have a dependency on many things: food, water, air, electricity. I doubt you would describe those dependencies as addictions (if you do you are truly a lost cause). There is no reason to describe a dependency on fossil fuels as an 'addiction' unless one is a member of a religious sect that thinks that fossil fuels are inherently bad.

The growth can't last forever - neither can the fossil fuels.

Actually, growth can last forever if the energy input per unit of GDP decreases. This has been happening for decades and the trend is downwards:

http://www.economist.com/blogs/dailychart/2011/01/energy_use

This trend will increase as the 'virtual economy' (electronically traded goods) expands around the world.

As for fossil fuels, they will run out eventually but for now they will have to do. We can eliminate coal for power generation today except nuclear is not acceptable to most followers of the enviro-cult (exceptions like Hansen exist). I suspect that this squeamishness around nuclear will disappear when the price of fossil fuels starts rising due to declining supply but that will take at least 50 years.

Edited May 21, 2013 by TimG