Climatologist challenges low-end claims of Intergovernmental panel

March 10, 2014 by Bob Yirka report
Climatologist challenges low-end claims of Intergovernmental panel
Global mean temperature change estimates based on anthropogenic forcings obtained from a multi-model analysis. Credit: Nature Climate Change (2014) doi:10.1038/nclimate2136

( —Drew Shindell, a climatologist and ozone specialist with NASA's Goddard Institute for Space Studies, has published a Letter piece in the journal Nature Climate Change challenging the findings of an intergovernmental panel that last fall concluded that average global temperatures are likely to increase by a minimum of 1.0°C over the next 70 years. Shindell claims the panel misinterpreted some important data which he says, if used correctly, would actually show a minimum rise 1.3°C over the same time period. In an accompanying News & Views piece, David Stainforth of the Grantham Research Institute on Climate Change and the Environment, London School of Economics, backs up Shindells claims and suggests that it's important that data used in creating projection models be as accurate as possible as such models are becoming increasingly important to policy-makers.

Last September, the Intergovernmental Panel on Climate Change (made up of climate experts from around the world) issued a report suggesting global warming may not be happening as quickly as some have thought, due to another type of pollution that causes temperatures to lower: aerosols. They noted that aerosols prevent heat from the sun from reaching the ground, thus reducing planet wide warming. Shindell agrees that aerosols do indeed lead to cooling but notes that the panel failed to recognize that such cooling only occurs around large cities, thus, it's not a global phenomenon, and thus it can't be presented as such in computer models. He claims that if adjustments are made to existing models, it would mean a minimum increase in global temperature of 1.3°C over the next 70 years, not 1.0°C . That small difference, most climatologists would agree, would be quite significant as it would likely represent bigger changes in weather patterns such as an increase in the number and strength of storms in some places and droughts in others.

Stainforth notes that as global warming has become accepted by most scientists around the world, those who make policy decisions have begun to take the issue more seriously. That means, he adds, that experts in the field need to be more careful when making estimates or predictions, because policy decisions might be riding on what is claimed. In the case of the discrepancy between the finding of the Intergovernmental panel and Shindell, it could mean major differences in how governmental entities plan for coming changes and how funds are allotted.

Explore further: Climate scientists want to interact more directly with the public

More information: Inhomogeneous forcing and transient climate sensitivity, Nature Climate Change (2014) DOI: 10.1038/nclimate2136


Understanding climate sensitivity is critical to projecting climate change in response to a given forcing scenario. Recent analyses have suggested that transient climate sensitivity is at the low end of the present model range taking into account the reduced warming rates during the past 10–15 years during which forcing has increased markedly. In contrast, comparisons of modelled feedback processes with observations indicate that the most realistic models have higher sensitivities5, 6. Here I analyse results from recent climate modelling intercomparison projects to demonstrate that transient climate sensitivity to historical aerosols and ozone is substantially greater than the transient climate sensitivity to CO2. This enhanced sensitivity is primarily caused by more of the forcing being located at Northern Hemisphere middle to high latitudes where it triggers more rapid land responses and stronger feedbacks. I find that accounting for this enhancement largely reconciles the two sets of results, and I conclude that the lowest end of the range of transient climate response to CO2 in present models and assessments7 (<1.3 °C) is very unlikely.

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2 / 5 (20) Mar 10, 2014
I think that none of you know what is going on with our climate. You guys argue over butterfly effects within flawed computer models and then expect the public to join your church of 'Global Warming'. You can not even tell me if it is going to rain next Thursday but expect me to believe you know what the temperature is going to be in the next century???...
Give your head a shake.
The Shootist
2.1 / 5 (21) Mar 10, 2014
If your climate models cannot accurately reproduce the past 70 years, why should we believe they can produce the next 70?

Still waiting for my chain of dairy farms in Greenland to exist for 400 years, as they did during the gloriously warm Medieval Climate Optimum.

And finally, "the polar bears will be fine." - Freeman Dyson
1.8 / 5 (16) Mar 10, 2014
The debate over climate change demonstrates the consequences of ignoring philosophy of science. The belief in the conclusions of climate science, with minimal discussion or even awareness of the philosophy of modeling, idealizes the process of science to something which is not reflective of reality. Then, the marketers take these failures to understand -- Daniel Kahneman would call them System 1 narratives -- and actually use them as tools for manipulating public opinion yet further.

It's all out in the open, but job scarcity ensures that even if people have the skills to do their own research on this, few people have the time.

Meanwhile, we have a growing skills gap that is happening right now. Obama could be solving it. But, instead, he's surrounded himself with these confused environmentalists. Our unemployment is now the result of the skills gap & it's here to stay.

The widening of the skills gap will stop all of this climate change discussion, but it will be a bit late.
2.6 / 5 (8) Mar 10, 2014
As long as we're talking politics, too. Obama will be seen as one of the best presidential leaders America has seen. He is black, which makes him an easy target for, well, how many racists are hiding behind their whiteness? (or blackness, but they usually don't target President Obama.) The widening of the skills gap is directly attributable to flawed, racist policies put in place by the white majority, many of whom have been working tirelessly behind the scenes to keep the poor and any minority population under their heels. Jesus did not support this hate, but religion seems to thrive by giving life to stories carried along since tribal days. The religious haters give attention to any tiny tidbit that they can find to misinterpret to support their bigotry. So much for the overly pious.

Technological creative destructionism will further enable the privileged to keep the majority desperate and powerless.
2 / 5 (8) Mar 10, 2014
Discover the cause of the warming, the end of it, why temperatures are headed down and what to expect.

There are only two primary drivers of average global temperature change. They very accurately explain the reported up and down measurements since before 1900 with R2>0.9 (correlation coefficient = 0.95) and provide credible estimates back to the low temperatures of the Little Ice Age (1610).

CO2 change is NOT one of the drivers.

The drivers are given at
3.8 / 5 (10) Mar 10, 2014
Climatologist challenges low-end claims
I've thought this for the longest time. In climate science we tend to present temperature changes and computer models that show "conservative" measurements. So far, the conservative measurements have been off by a significant percentage. The conservative models have a change from AGW of 1.0C over 70 years, but when you examine what has happened over the past 10-15 years and add that in to the models, it shows a much higher rise of 1.3C. The 1C to 1.3C is a global average temperature change and doesn't reflect the devastating local temperatures expected in specific regions. The Northern hemisphere could swing 2 -3C in the upper latitudes. A good example is the incredibly blazing hot temps Australia experienced this year during it's summer.

These are some pretty foreboding numbers that will devastate agriculture if these numbers come to bare. It will put pressure on mankinds ability to survive the great AGW.

4.6 / 5 (9) Mar 11, 2014
I think that none of you know what is going on with our climate. You guys argue over butterfly effects within flawed computer models and then expect the public to join your church of 'Global Warming'. You can not even tell me if it is going to rain next Thursday but expect me to believe you know what the temperature is going to be in the next century???...
Give your head a shake.

Sam, just because you don't understand it doesn't mean it is nonsense.
4.5 / 5 (8) Mar 14, 2014
Man, you DENIERs just don't get it. Do you? Man made global warming (Antropogenic Global Warming (AGW)) from the heat trapping greenhouse gasses is going to cook this world! Yet we can't stop it because of government inaction and teaparty resistance.

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