Is "Climate Sensitivity" the main issue that differentiates skeptics/deniers from alarmists?

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Climate sensitivity as stated by consensus scientists does seem to be reducing at the moment. This is a good thing because if it comes down enough it means we don't have a problem. Professor Myles ALlen of Oxford University has produced a YouTube video in which he says that an increase of 11 deg C is possible by 2100. Now he is the co-author of a paper that claims 2 deg C is likely.

Hey Dook is quoting from SkS again and slagging off mainstream climate scientists. How ironic that SkS is run by Cook and Nuccitelli. One is a cartoonist and the other is in the pay of Big Oil.

Did the U.S. National Academy of Sciences bother to ask any of its members about their statements, I wonder? Or was it just a politbureau bulletin?

All things global warming in wikipedia are monitored by William (And I've just made my 10,000th edit.) Connelly (AKA Stoat) who is not best known for his fair-minded and even-handed wiki changes....Show more

There is a difference between deniers and skeptics as well as between realists and alarmists. Deniers use whatever tidbit that seems to support their agenda, such as cold weather somewhere and ignoring heat waves, often at the same locales at different dates, as well as some glacier that is expanding while most glaciers are shrinking. They also ignore long term trends in temperature in favor of shorter terms, which can still be up to 20 years long, but have cherry picked start and end dates. And when confronted with evidence they don't like, they call that evidence a lie. It must be convenient for everything they don't want to hear to be a lie.

I think that there are very few actual alarmists. Even Greenpeace does not go so far as to advocate a ban on driving cars. An alarmist may suggest that doomsday scenarios are not only possible, but likely or even certain, unless we immediately stop burning fossil fuels, or even if we do. As I say, I am not aware of many alarmists, unless you count denialists who either claim that we should be afraid of the next ice age or that taking action to stop global warming means the end of Western civilization, or ay least of our freedoms. Another group of alarmists would be opponents of nuclear power, who claim that events like Three Mile Island and Fukushima actually kill large numbers of people.

Regarding the possibility that it could be worse than experts predict, as skeptics and deniers love to point out that computers models are at best, questionable. People say that computer models do not handle clouds very well, even though new empirical data can fix that. More serious is the fact that climate models have underestimated ice melt in the Northern hemisphere and overestimated sea ice gain in the Southern hemisphere. When your beachfront property is six feet umder water, will it matter whether Earth has warmed by 5 degrees C or only by 2 degrees C? The bottom line isn't how much temperatures rise (climate sensitivity) but the effects of what ever warming happens.

<When giving percentages and understanding the difference between Fahrenheit and Celsius we know that the spacing in degrees Celsius will give a higher percentage rate than what Fahrenheit gives.>

Percent change in temperature = Percent change in absolute temperature. The freezing point of water is 0 degrees C = 273 Kelvin = 32 Farenheit = 491 Rankine. A 1.8 Farenheit change is the same percentage of 491 Rankine as 1 degree Celsius is of 273 Kelvin, which is 0.366%...Show more

Climate sensitivity is a measure of how responsive the temperature of the climate system is to a change in the radiative forcing of the system.

Although climate sensitivity is usually used in the context of radiative forcing by carbon dioxide (CO2), it is thought of as a general property of the climate system: the change in surface air temperature (ΔTs) following a unit change in radiative forcing (RF), and thus is expressed in units of °C/(W/m2). For this to be useful, the measure must be independent of the nature of the forcing (e.g. from greenhouse gases or solar variation); to first order this is indeed found to be so[citation needed].

The climate sensitivity specifically due to CO2 is often expressed as the temperature change in °C associated with a doubling of the concentration of carbon dioxide in Earth's atmosphere.

For a coupled atmosphere-ocean global climate model the climate sensitivity is an emergent property: it is not a model parameter, but rather a result of a combination of model physics and parameters. By contrast, simpler energy-balance models may have climate sensitivity as an explicit parameter....Show more

Interesting perspective on the math Zippi!

Does a realist understand it though?

I agree with JC to a point. He seems to think there is evidence for action, but I sincerely disagree and agree with Spencer in that climate sensitivity is low.

The Chicago analogy does shed some light on temperatures and how people like antarcticice manipulate the actual temperature data. 10% is a stretch. LOL!

I'm not sure what to think about the 1.3%F and 1.37%C increases, but it seems right. I thought it was closer to 1% and have always used the 1% forcing of added CO2 by humans....Show more

It is certainly one of the main issues, but I agree with the others who differentiate between Skeptics and Deniers-to be fair, there is also a considerable difference between Alarmists and 'Realists,' (or Proponents, Warmists, etc.) Deniers and Alarmists are roughly equivalent in their disconnect with reality and science; it would certainly seem that on both sides of the argument people have become very frustrated with one another and both terms are tossed around rather indiscriminately, which escalates the tension between Realists and Skeptics. Perhaps nowhere is it more evident than here in this category of Y/A.

The Realists and Skeptics aren't really all that far apart on the science/theory itself but I think you are right, that climate sensitivity is where most seem to diverge in opinion. I personally believe (as a non-scientist, BTW) that the evidence suggests greater climate sensitivity than is proposed by the self-avowed Skeptics. One arena I am very interested in is 'average' global temperature increase vs. regional variations and the influences on weather as those variations are equalized. While the average might appear to be minor, the regional variations might be major and as the system works to achieve equilibrium it certainly seems evident that weather extremes would increase. The issue is how much influence mankind's activities have on natural processes.

The greater disagreement between the Skeptics and Realists is, of course, our response to the evidence before us, with some Skeptics taking a 'wait and see' position for economic and political reasons while the Realists believe there is sufficient evidence to warrant action in various ways. Of course, regardless there is already an environmental, economic and political juggernaut that is gaining momentum as alternative energy sources are researched and developed. So what we see are people and organizations digging in their heels to try to slow the increasing momentum of that juggernaut down. So that is why you can see the conservatives among us are more likely to be on the anti-AGW side of the argument, as well as why the science has been co-opted by the ideological argument and that, in turn, feeds denial.

EDIT: Pat suggests that I seem to advocate for action based on my opinion about climate sensitivity but I'm not sure I intended to imply that; rather, my concern is that if we take economic (and geopolitical) action solely to mitigate climate change in the face of uncertainty, that is not a wise course of action and indeed, could upset a tenuous global economy as well as destabilize developed nations in a way that could lead to greater social harm sooner than AGW is likely to. Rather, we need to minimize risk by developing technologies with multiple benefits; alternative energy, although costly to develop relative to the use of fossil fuels, addresses multiple short and long term needs aside from any potential benefit it might offer in terms of helping to minimize the impacts of AGW. I trust in this particular exercise it isn't necessary to elaborate on the specifics. Conversely, I am not in favor of strategies solely designed to remove CO2 immediately, shifting political power through economic measures or worldwide governing bodies from developed nations to consortiums of small countries whose goal is to develop economically with financial aid from the developed countries while simultaneously punishing those same countries for their carbon footprint, or other policies that do not have other benefits for the countries who practice them.

That being said, I would like to study the less/more climate sensitivity issue more, and I think this conversation about it is interesting, very worthwhile and discussed in the spirit I would like to see more of the debate conducted. Great question!...Show more