Moderated Global Warming Discussion

[BenBurch]

Got one that explains the time when the Romans had vinyards in Britain? ...

You're smart enough to debunk that one for yourself, I think. Clearly you have not tried; Britain is an island, and its climate is greatly effected by currents. And we know that ocean currents have changed over time. And its not controversial that climate has changed in the past; Climate changes in response to its inputs. But what is different NOW is that we have added an input that we have not seen in the past, and that climate is responding to this input in accord with predictions of its effect.

See;

http://www.skepticalscience.com/climate-change-little-ice-age-medieval-warm-period.htm

http://www.skepticalscience.com/1500-year-natural-cycle.htm

http://www.skepticalscience.com/medieval-warm-period.htm

http://www.skepticalscience.com/greenland-used-to-be-green.htm

http://www.skepticalscience.com/CO2-is-not-the-only-driver-of-climate.htm

 

[Trakar]

Pick up any introductory textbook on climtate sceince.

In case you missed it the work he's referring to predates the internet and electronic formats so asking for links is clearly a red herring on your part.

On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground
Svante Arrhenius
Philosophical Magazine and Journal of Science
Series 5, Volume 41, April 1896, pages 237-276.

http://www.globalwarmingart.com/images/1/18/Arrhenius.pdf

"... A simple calculation shows that the temperature in the Arctic regions would rise about 8º to 9º C., if the carbonic acid increased to 2.5 or 3 times its present value..."

among other interesting nuggets of information, assessment and prediction.

 

[BenBurch]

On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground
Svante Arrhenius
Philosophical Magazine and Journal of Science
Series 5, Volume 41, April 1896, pages 237-276.

http://www.globalwarmingart.com/images/1/18/Arrhenius.pdf

"... A simple calculation shows that the temperature in the Arctic regions would rise about 8º to 9º C., if the carbonic acid increased to 2.5 or 3 times its present value..."

among other interesting nuggets of information, assessment and prediction.

Ah, thank you! I had posted that as a part of another post that was more-or-less off-topic.

We have known the effects of CO2 for 115 years, and suspected them for much longer than that. Note that Arrhenius was shown to have underestimated the magnitude of a doubling increase because he did not consider the knock-on effects.

 

[Matt Giwer]

We are discussing global warming and globally temperatures between 1940 and 1980 are right in line with model predictions. As has been pointed out to you multiple times the slight global cooling between 1940 and 1970 is readily attributable to global dimming. Sunlight reaching the earths surface has decreased as much as 4% since 1950 mostly due to anthropogenic aerosols as the Suns output has only decreased modestly in that time. BTW, a 4% decrease in Sunlight is massive, considering that the Suns output normally only varied by a few tenths of a percent at most.

When I was first told of the global dimming a URL was given. I read the URL and it very clearly said some parts of some countries. I pointed that out and asked how one gets from some parts of some countries to global. Do you have an answer this time?

 

[Matt Giwer]

Originally Posted by Matt Giwer View Post
The total anomaly shown in the temperature graph is only 1/2 degree centigrade or 0.166%.

Eh? I’m not at all sure what you are trying to say here. Over the last 100 years the earth has warmed by ~1 deg C, non-anthropogenic forcing is typically credited with ~0.2 deg of that Almost all of the non-anthropogenic forcing was in the period from 1900-1940.

I am pointing out that the 1/2 of 1 degree C indicated on the graphs associated with the URL suggests a 0.166% increase in heat content. As I noted when I first pointed this out it indicates a remarkable stability.

If you folks do not agree on your source material I request you settle it among yourselves and get back to me.

As we know greater changes are indicated in historical records than this 0.166% change which is still not indicated to be other than a short term trend melters have nothing but a coincidence which does not exist without a lot of hand-waving and appeals to unexplainable other factors. If you believe these factors have been explained to your satisfaction then explain them to me.

 

[Matt Giwer]

You are aware there are vineyards in England today right?

Correct. I should have exactly repeated my first assertion about "vintage wines" instead of generic vinyards. Yes there are vinyards in New England too. What would Welch's do without them?

 

[Matt Giwer]

On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground
Svante Arrhenius
Philosophical Magazine and Journal of Science
Series 5, Volume 41, April 1896, pages 237-276.

http://www.globalwarmingart.com/images/1/18/Arrhenius.pdf

"... A simple calculation shows that the temperature in the Arctic regions would rise about 8º to 9º C., if the carbonic acid increased to 2.5 or 3 times its present value..."

among other interesting nuggets of information, assessment and prediction.

The Northwest Passage opens. Canada and Siberia become breadbaskets to the world. Holland gets rich exporting dike technology -- the other kind.

As the world changes to nuclear power there is a global crisis seeking ways to keep CO2 levels elevated to preserve the post 20th c. prosperity.

 

[ProBonoShill]

The letter was published by the author here. Enjoy. It's a sign of things as they are and have been always.

The parts you highlighted represent previously expressed opinions. The whole thing is presented as an outburst and as some kind of breaking point of whatever. The fact is that Lewis was one of the group circulating this letter last December and it seems like there's nothing new there but the resignation. He now will be able to write a book with Plimer or any other holding his opinions.

How are called in English the episodes of a series that are made up by chunks taken from previous episodes, all following a kind of absurd theme to give cohesion to something intentionally made from leftovers? Well, that piece of news is it.

The letter was authored by these people:

Bob Austin, Professor of Physics, Princeton
Hal Lewis, emeritus Professor of Physics, University of California, Santa Barbara
Will Happer, Professor of Physics, Princeton
Larry Gould, Professor of Physics, Hartford
Roger Cohen, former Manager, Strategic Planning, ExxonMobil


Are we to believe they're incompetent or are politics involved?


Also I found this in the comment section:

I have heavily researched and thoroughly studied this subject matter for well over a decade, and I did so with the aide of a close acquaintance who's a department head at the USGS (A Climatologist), as well as with the great assistance of NOAA scientists. I can tell you, without a doubt, that NOTHING we are currently experiencing climate-wise is anywhere near the limits of historically proven fluctuations. Time and again, oceanic level studies, glacier core samples, and CO2 traces have proven beyond a doubt, that we are currently very fortunate to be on a mild crest of moderation within Earth's cyclic climatological track-record. For much of Earth's history, it was far hotter than now, and for much of Earth's history as well, it was also much colder.

If you look at organized human civilization for instance, it first emanated from a planet that was warming towards moderation. Such a facet never existed until our current climatological peak (Which came about thousands of years ago). We have had four global temperature peaks in the past 400,000 years, and all of organized civilization has only existed upon the current one (The fifth peak). Within this set peak, there are constant variances (Troughs and crests), but overall we should count ourselves very fortunate to be existing upon it at all! If anything, you should worry more about the next major glacial period, because, as proven throughout history, it will occur again (We will be the first organized civilization to face it as well, if we are still around that is).

The bottom line, is that the aforementioned set pattern proves the natural variances of Earth's cyclic climate drama. Combine that with the fact that we are currently well within the pre-established parameters, and human forcing becomes negligible at best, unmeasurable at worst.

Any truth to this or is it bunk?

 

[metzomagic]

Any truth to this or is it bunk?

Bunk. It is at best an argument from incredulity.

That diatribe completely ignores the fact that in the past 400,000 years of ice core samples that it alludes to, the atmospheric CO2 concentration has never been above 280ppm. It is now, just since the start of the industrial revolution in 1780 or so, at 390ppm and rising exponentially. It has so far caused a rise in global temperatures of around 0.7C - 0.8C in that short period, which so far as we can tell is unprecedented.

 

[aleCcowaN]

The letter was authored by these people:

Bob Austin, Professor of Physics, Princeton
Hal Lewis, emeritus Professor of Physics, University of California, Santa Barbara
Will Happer, Professor of Physics, Princeton
Larry Gould, Professor of Physics, Hartford
Roger Cohen, former Manager, Strategic Planning, ExxonMobil


Are we to believe they're incompetent or are politics involved?

The authors were already included in the link. Guessing motivations is what makes political what is a matter of science. Is "competence" what makes valid an argument? Let's see: "That is true because it was said by a competent person", "that is false because it was said by an incompetent" ¡Hmmm! I don't think so. It looks quite like argumentum ad verecundiam to me. We have to look towards what they said.

Also I found this in the comment section:

<snipped: some argumentation>

Any truth to this or is it bunk?

I didn't find it in the comment section of each of both linked pages. Can you provide a link to those texts? Are you telling that those texts were written by all or any of the authors you listed? I'm asking because the lay-out of your post might induce the inference that those authors were saying those paragraphs.

 

[macdoc]

None - they are trying to insert geologic climate variations when the only ones that matter to our current civilization is the range in the Holocene which we are rapidly departing.
The Exxon referral and failure to name the "climatologist "- it's just more political posturing....the industry's scientists told their superiors the truth of the matter in the mid 90s..

Industry Ignored Its Scientists on Climate

By ANDREW C. REVKINPublished: April 23, 2009

For more than a decade the Global Climate Coalition, a group representing industries with profits tied to fossil fuels, led an aggressive lobbying and public relations campaign against the idea that emissions of heat-trapping gases could lead to global warming.

“The role of greenhouse gases in climate change is not well understood,” the coalition said in a scientific “backgrounder” provided to lawmakers and journalists through the early 1990s, adding that “scientists differ” on the issue.

But a document filed in a federal lawsuit demonstrates that even as the coalition worked to sway opinion, its own scientific and technical experts were advising that the science backing the role of greenhouse gases in global warming could not be refuted.

Industry Ignored Its Scientists on Climate - NYTimes.com
http://www.nytimes.com/2009/04/24/science/earth/24deny.html?_r=2

time to move on to the "how to cope" and "reduce the impact phase"

The letter is just residual debris from Exxon and others fossil fuel industry funded disinformation campaign.....which was serious enough for the Royal Society to call Exxon to task directly for it's role - and action unprecedented -
The Rockefeller family to it's credit staged a shareholder revolt over the same funding by Exxon....
This is where the science resides...and this was several years ago...

Here is what Gammon had to say concerning links between humans and climate change.

This is like asking, ‘Is the moon round?’ or ‘Does smoking cause cancer?’ We’re at a point now where there is no responsible position stating that humans are not responsible for climate change. That is just not where the science is.…For a long time, for at least five years and probably 10 years, the international scientific community has been very clear.”

In case there is any doubt, Gammon went on:
This is not the balance-of-evidence argument for a civil lawsuit; this is the criminal standard, beyond a reasonable doubt We’ve been there for a long time and I think the media has really not presented that to the public.”

Dr. Richard H. Gammon
Professor of Chemistry and Oceanography*
Adjunct Professor Atmospheric Sciences, University of Washington

Gammon IS a climate scientist working in the field with boots on the ground, not a physicist commenting on a field outside his ken and receiving funding from right wing oil funded think tanks.

Let's pick one of the signers at random, Will Happer,

http://www.desmogblog.com/will-happer-testify-congress-climate-science

you can most likely type in any of the others and get the same oil-tainted CV

 

[BenBurch]

It's bunk, PBS.

What differs NOW is that we know what the forcing is, and we are causing it.

Also, that climate has varied more in the past does not mean a similar excursion now would be at all beneficial for human civilization. Think of sea levels 18 meters above present. What would that do to Manhattan? To Florida? If we keep pumping the greenhouse, that is not an impossible result.

In fact, if all ice melts, a sea level rise of 65 meters is possible. Three million years ago, Antarctica was ice-free.

London is 9 meters ASL.

Rome is 14 meters ASL.

Houston is 13 meters ASL.

So, the fact that the planet has been warmer than this in the past does not mean that we would find this to be a good thing. In fact, it would be a calamity.

 

[lomiller]

When I was first told of the global dimming a URL was given. I read the URL and it very clearly said some parts of some countries. I pointed that out and asked how one gets from some parts of some countries to global. Do you have an answer this time?

What an odd question. The global effect is the sum total of the regional effect. Why are you suggesting it’s impossible to know both?

I am pointing out that the 1/2 of 1 degree C indicated on the graphs associated with the URL suggests a 0.166% increase in heat content. As I noted when I first pointed this out it indicates a remarkable stability.

Relative to what? You have not context to say whether that’s a tiny change or a massive one. Surely you don’t think that “it doesn’t matter just because the number is less then 1”?

BTW temperature != heat content. The heat uptake in the oceans over the last 30 years is an order of magnitude greater then the impact energy of the asteroid that wiped out the dinosaurs. The energy required to melt the ice Greenland is currently loosing is comparable to several thousand Hiroshima atomic bombs every year. On any human scale we are talking about massive amounts of energy.

Correct. I should have exactly repeated my first assertion about "vintage wines" instead of generic vinyards. Yes there are vinyards in New England too. What would Welch's do without them?[/QUOTE
Again a puzzling response on your part? Are you saying roman wine is comparable to what we drink today? The better English and Welsh wines, particularly sparkling wines, routinely do well in taste tests and certainly rank far better then “grape juice”.
http://www.english-wine.com/history.html

The Northwest Passage opens. Canada and Siberia become breadbaskets to the world. Holland gets rich exporting dike technology -- the other kind.

Canada is already one of the world’s larger exporters of grain, but global warming threatens that. Current grain producing regions in Canada are dry and if they get much dryer they would no longer be suitable for grain production. Land further north may become warmer but the soil is unsuitable for agriculture of any kind.

Economic activity in Northern Canada and Alaska is already under threat as it depends heavily on ice roads and but warming temperatures are shortening the shipping season. Last year some communities couldn’t even get enough food trucked in to feed them for the year and needed emergency supplies shipped in by small aircraft.

 

[lomiller]

Are we to believe they're incompetent or are politics involved?

Let me explain how these things work. If you want to reference an expert, you need to demonstrate that person truly is an expert in the field.

In the absence of such proof we can’t treat these people as experts because every woo imaginable can find people with letters behind their name that endorse their woo. In short, if you want to call these people climate experts show us they have published climate related papers in significant journals within the last decade. A quick Google scholar search, on Bob Austin with the keyword, for example yields no published papers in the last decade. Why should we accept him as a climate expert when he has published absolutely no relevant papers?

If you look at organized human civilization for instance, it first emanated from a planet that was warming towards moderation.

Until the last 100 years it’s been cooling since the Holocene maximum 8000 years ago, which predates the rise of any significant civilization.

We have had four global temperature peaks in the past 400,000 years, and all of organized civilization has only existed upon the current one (The fifth peak).

The last time it was significantly warmer then today was 125kya at which point it was ~3 deg warmer then 1950, ~2 de warmer then today and about as warm as it’s expected to be in the second half of this century. Not only did human civilization not exist back then, neither did our sub-species homo sapiens sapiens. One thing we do know about this period is that it was warm enough to raise sea levels 20 feet above where they are today.

Clearly just because it was warmer then today before fully modern humans let alone human civilization even existed doesn’t mean it’s “all right” for it to get that warm in the next 100 years.

! If anything, you should worry more about the next major glacial period, because, as proven throughout history, it will occur again (We will be the first organized civilization to face it as well, if we are still around that is).

If you ignore the effects humans have had the next serious brush with a glaciations would be 17 000 from now, but that is expected to have failed. The next glacial period would likely have been some 50 000 years from now.

The bottom line, is that the aforementioned set pattern proves the natural variances of Earth's cyclic climate drama. Combine that with the fact that we are currently well within the pre-established parameters, and human forcing becomes negligible at best, unmeasurable at worst.

Any truth to this or is it bunk?

Bunk for sure. The cause for the pattern of glaciations is reasonably well understood. We should be in a modest cooling trend and instead we are in a 100 period where it’s warmed faster then any time other then the end of a glaciations. There is no interglacial warm period in the last 2 million years where the planet has subsequently warmed another 2-4 degrees in a couple centuries.

 

[Mikemcc]

The Northwest Passage opens. Canada and Siberia become breadbaskets to the world. Holland gets rich exporting dike technology -- the other kind.

As the world changes to nuclear power there is a global crisis seeking ways to keep CO2 levels elevated to preserve the post 20th c. prosperity.

Northwest passage opening means that circulation patterns change both in the sea and atmosphere with further knock-on effects. Also opening up the region to exploitation and potential conflict (as shown by the Russians, Canada and the US).

Just because temperatures increase does not necessarily mean that the soils become useful arable land

How much are these dikes going to cost? What about the cost of their potential failure? How does it help the people of places like Bangladesh?

Then there's the problem of changes in water distribution. Himalyan glaciers feed many rivers that support a significant portion of the worlds population, their eventual loss will cause massive problems.

 

[oponol]

Any truth to this or is it bunk?

It's bunk.

Consider this part:
"NOTHING we are currently experiencing climate-wise is anywhere near the limits of historically proven fluctuations....For much of Earth's history, it was far hotter than now, and for much of Earth's history as well, it was also much colder."

It's a strawman, deliberately or not. We don't need to reach the limits of Earth's history for there to be a problem. If we experienced a 10 meter sea level rise, "climate-wise that wouldn't be anywhere near the limits of historically proven fluctuations" in sea level. Yet 10 meter sea level rise would be a problem.

Also the limits of climate change over Earth's entire 4.5 billion year history is completely irrelevant to us, a species that's only been around for a few hundred thousand years with a civilization barely 10,000 years old? Even with regard to other species that exist today, is the climate in the Cambrian really relevant? Does the fact that ancient lifeforms survived in the Cambrian mean it will be fine for all species today? In a sci-fi this would be a bit like the captain of a ship saying that because the aliens are doing just fine on a newly discovered planet, therefore we can safely land men on it without suits.

Even the author seems to realize his above argument is wrong because he contradicts it by stating:
"you should worry more about the next major glacial period, because, as proven throughout history, it will occur again"

Ah but why should we worry when a glacial period is "nowhere near the limits of historically proven fluctuations"?

What's most ironic is that many of the author's points are actually a good case for human induced climate change being a problem. If the climate swings all over the place in the past then how easy would it be for us to accidentally knock it about a bit?

The author doesn't provide any reason why we can't do that, just states that our contribution is dwarfed by natural variation - which is a bit of a circular argument.

The piece of data that the author fails to consider is how CO2 is changing:

The co2 level going back to 650,000 years is from ice cores. It's the limit of the ice core, however the climate behavior goes back many more millions of year. Other proxies suggest you have to go back 15 million years to encounter co2 levels as high as they were today. Even then there's no evidence of such a large co2 change as is happening now occuring in the space of a few centuries.

And it's as much the rate of change that causes problems as the magnitude of changes. Because co2 has spiked up 100ppm in less than 200 years, natural systems have less time to adjust than if it had risen 100ppm in 2,000 years. For example there is a balance between the amount of co2 in the atmosphere and the amount of disolved co2 in the upper ocean. When atmospheric co2 is forced upward this prompts the oceans to start absorbing more co2 until balance is restored. A side effect of this is ocean pH drops. If the forced co2 jump in the atmosphere happens gradually then the ocean has more time to spread the disolved co2 around. If it happens rapidly then the ocean has less time and you get large pH drop in the surface ocean. Because of the rate of co2 rise in the past 200 years, it is thought that the associated ocean pH drop will be very significant in context of geological time. I've seen a figure of 300 million years cited.

 

[Mr Clingford]

A sign of things to come perhaps?
The full letter can be found at the link provided.

Here's some of the fun stuff. Bolded is mine.

http://wattsupwiththat.com/2010/10/08/hal-lewis-my-resignation-from-the-american-physical-society/

Sent: Friday, 08 October 2010 17:19 Hal Lewis

From: Hal Lewis, University of California, Santa Barbara
To: Curtis G. Callan, Jr., Princeton University, President of the American Physical Society

It is of course, the global warming scam, with the (literally) trillions of dollars driving it, that has corrupted so many scientists, and has carried APS before it like a rogue wave. It is the greatest and most successful pseudoscientific fraud I have seen in my long life as a physicist. Anyone who has the faintest doubt that this is so should force himself to read the ClimateGate documents, which lay it bare. (Montford’s book organizes the facts very well.) I don’t believe that any real physicist, nay scientist, can read that stuff without revulsion. I would almost make that revulsion a definition of the word scientist.

The APS reply
http://www.aps.org/about/pressreleases/haroldlewis.cfm

"On the matter of global climate change, APS notes that virtually all reputable scientists agree with the following observations:

* Carbon dioxide is increasing in the atmosphere due to human activity;
* Carbon dioxide is an excellent infrared absorber, and therefore, its increasing presence in the atmosphere contributes to global warming; and
* The dwell time of carbon dioxide in the atmosphere is hundreds of years.

On these matters, APS judges the science to be quite clear. However, APS continues to recognize that climate models are far from adequate, and the extent of global warming and climatic disruptions produced by sustained increases in atmospheric carbon loading remain uncertain. In light of the significant settled aspects of the science, APS totally rejects Dr. Lewis’ claim that global warming is a “scam” and a “pseudoscientific fraud.”"

 

[Trakar]

The letter was authored by these people:

Bob Austin, Professor of Physics, Princeton
Hal Lewis, emeritus Professor of Physics, University of California, Santa Barbara
Will Happer, Professor of Physics, Princeton
Larry Gould, Professor of Physics, Hartford
Roger Cohen, former Manager, Strategic Planning, ExxonMobil


Are we to believe they're incompetent or are politics involved?


Also I found this in the comment section:

I have heavily researched and thoroughly studied this subject matter for well over a decade, and I did so with the aide of a close acquaintance who's a department head at the USGS (A Climatologist), as well as with the great assistance of NOAA scientists. I can tell you, without a doubt, that NOTHING we are currently experiencing climate-wise is anywhere near the limits of historically proven fluctuations. Time and again, oceanic level studies, glacier core samples, and CO2 traces have proven beyond a doubt, that we are currently very fortunate to be on a mild crest of moderation within Earth's cyclic climatological track-record. For much of Earth's history, it was far hotter than now, and for much of Earth's history as well, it was also much colder.

If you look at organized human civilization for instance, it first emanated from a planet that was warming towards moderation. Such a facet never existed until our current climatological peak (Which came about thousands of years ago). We have had four global temperature peaks in the past 400,000 years, and all of organized civilization has only existed upon the current one (The fifth peak). Within this set peak, there are constant variances (Troughs and crests), but overall we should count ourselves very fortunate to be existing upon it at all! If anything, you should worry more about the next major glacial period, because, as proven throughout history, it will occur again (We will be the first organized civilization to face it as well, if we are still around that is).

The bottom line, is that the aforementioned set pattern proves the natural variances of Earth's cyclic climate drama. Combine that with the fact that we are currently well within the pre-established parameters, and human forcing becomes negligible at best, unmeasurable at worst.

Any truth to this or is it bunk?

As stated, it is bunk.
climate does not just randomly and without cause vary between extremes. Climate responds to and is the result of very specific but complexly interacting
factors. Though we are still learning the particulars of many of the interactions, we have robust understandings of most of the general factors and processes and can to a fair degree of accuracy assess and indicate the current situation, trends and causative factors/agencies.

 

[macdoc]

Originally Posted by ProBonoShill
! If anything, you should worry more about the next major glacial period, because, as proven throughout history, it will occur again (We will be the first organized civilization to face it as well, if we are still around that is).

nope - it has been indefinitely delayed by our actions.

Next Ice Age Delayed by Burning of Fossil Fuels
Written by Simmons
l!
Future ice ages may be delayed by up to half a million years by our burning of fossil fuels, according to a new study released by researchers lead by Dr. Toby Tyrell at the University of South Hampton

http://www.environmentalgraffiti.com/sciencetech/next-ice-age-delayed-by-burning-of-fossil-fuels/251

This is what people don't seem to get....carbon persists...it does not drop out quickly the way most other GHG do.
In human scale it is there indefinitely unless we actively remove it.
So if we raise it 1/3 as we have....and the planet has not seen that level for 15 million years......then it stays close to that - each year accumulates and the radiative balance alters towards the warm end of the change.
What we already have altered, is not fully expressed either....
Another .6C is in the pipeline as it takes time to reach a new radiative balance....60 years or so.

Your lawn mowing today with a fossil fuel will have persistent impact upwards of 100k years.
Even if we stopped cold turkey - it would not return to pre-industrial levels for 100s of millenia and the atmosphere and ocean continue to warm until a new radiative equilibrium is reached.
The thin edges of change are already here, there is a nothing short of removing carbon from the atmosphere to counter the changes that are "in progress ".
We CAN slow future impacts by reducing carbon output now...we will not eliminate those impacts.

We will get hit by the train that is already in motion.....the severity of the hit is uncertain both due to some climate uncertainties ( tipping points ) but most of all the uncertainty of how much carbon we will release.

No one can predict the latter....
The only benchmark....if we burn it all....we are in serious trouble.

 

[macdoc]

A good article that brings the scale of the risks into focus....

A detailed look at climate sensitivity
Debunking the dangerous anti-science fantasy of the 'lukewarmers'
September 19, 2010

The amount of warming we are going to subject our children and countless future generations to depends primarily on three factors:

1. The sensitivity of the climate to fast feedbacks like sea ice and water vapor (how much warming you get if we only double CO2 emissions to 560 ppm and there are no major “slow” feedbacks). We know the fast feedbacks are strong by themselves (see Study: Water-vapor feedback is “strong and positive,” so we face “warming of several degrees Celsius” and detailed analysis below).
2. The real-world slower (decadal) feedbacks, such as tundra melt (see Science: Vast East Siberian Arctic Shelf methane stores destabilizing and venting and links at the end).
3. The actual CO2 concentration level we are likely to hit, which is far beyond 550 ppm (see U.S. media largely ignores latest warning from climate scientists: “Recent observations confirm … the worst-case IPCC scenario trajectories are being realised” — 1000 ppm).

Given that the anti-science, pro-pollution forces seem to be succeeding in their fight to keep us on our current emissions path, it’s no surprise that multiple recent analyses conclude that we face a temperature rise that is far, far beyond dangerous:

* Hadley Center: “Catastrophic” 5-7°C warming by 2100 on current emissions path
* M.I.T. doubles its 2095 warming projection to 10°F — with 866 ppm and Arctic warming of 20°F
* Our hellish future: Definitive NOAA-led report on U.S. climate impacts warns of scorching 9 to 11°F warming over most of inland U.S. by 2090 with Kansas above 90°F some 120 days a year — and that isn’t the worst case, it’s business as usual!”
* “The Copenhagen Diagnosis” warns “Without significant mitigation, the report says global mean warming could reach as high as 7 degrees Celsius by 2100.”

And this is all consistent with the best recent analyses of paleoclimate data (see Science: CO2 levels haven’t been this high for 15 million years, when it was 5° to 10°F warmer and seas were 75 to 120 feet higher — “We have shown that this dramatic rise in sea level is associated with an increase in CO2 levels of about 100 ppm”).

There is a small group of self-proclaimed “lukewarmers” who don’t know the scientific literature well or are just outright anti-science disinformers. They assert, despite all the science to the contrary, that the sensitivity of the climate to fast feedbacks is very low. They then blindly ignore factors #2 and #3 above in order to claim total warming this century will be maybe 1°C — or 2°C at most — no big deal, according to this dangerously confused and/or misguided group.

Skeptical Science has a good post on this, “A detailed look at climate sensitivity,” that I am reprinting in its entirety below.

There are numerous links embedded for further use and the article continues
http://climateprogress.org/2010/09/19/climate-sensitivity-lukewarmers/

continues
This is the referenced article http://www.skepticalscience.com/detailed-look-at-climate-sensitivity.html