Icemelt Could Shift Earth's Rotation, Moving Water Northward

WASHINGTON — Long-term sea level increases that could have a devastating effect on southern Florida and highly populated coastal areas may be even larger than once thought, a report suggests.

Some studies have suggested that melting of ice in Antarctica and other areas could raise sea levels by 16 feet to 17 feet over the long run, a potential threat to coastal areas such as Washington, D.C., New York City and California.

But a report in Friday's edition of the journal Science warns that factors not previously considered could one day boost that increase to up to 21 feet in some areas.

The study did not list a time frame for such a dramatic change. But co-author Peter Clark, a geoscientist at Oregon State University, stressed that they "aren't suggesting that a collapse of the West Antarctic Ice Sheet is imminent."

The most recent International Panel on Climate Change report estimated sea level rise of up to 3 feet by the end of this century.

"People have been trying prepare for sea level rise for some time, it's not a new issue," Clark said, noting that the U.S. Fish and Wildlife Service and U.S. Geological Survey are holding a meeting in San Francisco on the effects of coastal change.

Earlier research has focused on melting ice adding water to the oceans and on thermal expansion of sea water in a warmer climate over long periods of time.

In the new report geophysicist Jerry X. Mitrovica and physics graduate student Natalya Gomez of the University of Toronto, Canada, and Clark, say other factors need to be considered.

Story continues below

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_When an ice sheet melts, its gravitational pull on the ocean is reduced and water moves away from it. That means sea levels could fall near Antarctica and rise more than expected in the northern hemisphere.

_Antarctic bedrock that currently sits under the weight of the ice sheet will rebound from the weight, pushing some water out into the ocean.

_The melting of the West Antarctic ice sheet will cause the Earth's rotation axis to shift, potentially moving water northward.

"The net effect of all of these processes is that if the West Antarctic ice sheet collapses, the rise in sea levels around many coastal regions will be as much as 25 per cent more than expected," Mitrovica said in a statement.

___

On the Net:

Science: http://www.sciemcemag.org

Comments

[RobTaylor]

I'm sorry, but this is a joke right? Your source is a made for Adsense site and there are no reputable scientist who think melting sea ice would change the rotation of the earth, which isn't even what the article says in the first place.

Let me ask a question here. If I build a page on the Internet with a nice header is there anything on it you wouldn't believe?

[Mykel]

The very axis of our planet could shift?

Because of 50 years of fat, car-addicted suburbanites?

Great. Just great.

Perhaps they will finally lose their appetites when they look up one day and see the stars rushing across the sky as the world tips over.

[Exusian]

"The very axis of our planet could shift?"

It shifted ever so slightly--about an inch--as the lake filled behind the Three Gorges Dam, too.
Earth's speed of rotation also slowed ever so slightly.

[realpolitic]

Climate change denier Bjorn Lomberg was on a talk show this morning debating how to respond to climate change with Dr. Jeffrey Sachs. Of course, Lomberg advocated doing little. Tellingly, Dr. Sachs spoke with Lomberg as if he were talking with a small child. Lomberg just iterated a series of false choices. Most insidiously, Lomberg would not even admit that all his pronouncements on the science to date have been wrong, like his insistence that the Artic ice cap was not losing ice mass or that polar bear populations were not threatened. Lomberg now wisely tried to limit his arguments to the cost-benefit analysis of what to do. It is in this direction of how to respond to warming that deniers should take their arguments. Otherwise, they look like high school kids who have not done their homework.

[UbiVeritas]

Actually, a lot of us are not deniers -- we're just skeptics (like most good scientists). We're suspicious of the shrill and accusatory tone of AGW believers, who are absolutely certain beyond any doubt that the IPCC computer models are correct, even though they failed to predict the current 12-year stable temps. Co2 was continuing to increase during this period, so if all of the forcing hypotheses are correct, temps should have continued to climb. The models are missing something, and the IPCC gurus don't know what that something is.

We also resent being told that climate science is so incredibly unbelievably complex that mere mortals could never pretend to understand it. I'll agree it's complex, which is one more reason to doubt the models -- they pile assumption upon assumption upon assumption, and then pretend to be able to predict temps 100 years from now. Not a believable scenario.

Finally, it's just a little too convenient that the policy prescriptions outlined by AGWers dovetail nicely with the extreme environmentalist agenda, which is hostile to capitalism. Although I have always driven a subcompact, recycle dutifully, live in a modest house and don't jet around like Al Gore, I'm typical of many people who don't like to be manipulated by other people who think of themselves as everyone's intellectual superior and want to tell everyone else how to live.

[realpolitic]

I think you have to look at the science by itself, and consider agendas secondarily. There is plenty of time for discussions about agendas when policy alternatives to climate change are implemented. That is when the policy prescriptions of conservatives can be taken into account, because science is neither conservative or liberal.

[Exusian]

But that's just it, Veritas, there has been no 12-year period of stable temps. You are being fed deliberately fabricated misinformation.
Temperature continued to rise until only recently.

See: Global-mean monthly, annual and seasonal dTs based on met.station data
http://data.giss.nasa.gov/gistemp/tabledata/GLB.Ts.txt

year J-D D-N
1994 32 29
1995 46 46
1996 39 38
1997 41 40
1998 72 70
1999 46 49
2000 42 42
2001 57 55
2002 69 70
2003 67 65
2004 60 61
2005 76 76
2006 66 66
2007 74 76
2008 54 55

Or: Global-mean monthly, annual and seasonal land-ocean temperature index
http://data.giss.nasa.gov/gistemp/tabledata/GLB.Ts+dSST.txt

year J-D D-N
1994 24 22
1995 38 38
1996 30 29
1997 40 38
1998 57 57
1999 33 34
2000 33 34
2001 48 46
2002 56 57
2003 55 52
2004 48 50
2005 62 62
2006 55 54
2007 57 59
2008 44 43

In both anomaly sets 1998 was clearly an anomalous outlier, caused by the exceptionally strong El Nino. Picking it as the start of any comparison, as is often done by "skeptics," would be either naive or deliberately deceptive. Also clearly in both data sets, the positive temperature trend did not peak until 2005. There certainly has NOT been a 12-year period of stable temps.

[NL207]

Which NASA/GISS dataset is this one? The one that was adjusted incorrectly in the year 200 or the newer one that was adjusted incorrectly in 2008?

[Exusian]

You can use HADCRUT or RSS if you like, but I'm sure you'll dismiss them, too.

[Exusian]

As for why temperature hasn't continued to climb steadily since CO2 has continued to increase steadily, no climate scientist ever suggested that CO2 is the only factor and there is still natural variability, just as there always has been. Why would you expect it to suddenly cease just because we're adding CO2 to the atmosphere?

El Nino still occurs, temporarily pushing the trend well above what was expected in 1998, as does La Nina, pushing down during the winter of 2007-2008. El Nino-La Nina are not strictly periodic, however, so it is not possible to predict them ahead of time in a model, only their long term aggregate effect.

Major volcanoes still erupt and produce temporary cooling, as Pinatubo did in 1991. But eruptions are random and unpredictable. (Although the resulting cooling of a random eruption included in some models was successfully predicted, btw.)

continued....

[NL207]

Denial. That can be the only explanantoin. The mere fact that CO2 has been monotonically increasing over the last 150 years and the temperatures have not is proof that the natural variations in the system can and will dominate CO2 concentration increase, whether it is of human origin or not.

That you cannot accept this fact is denial.

People like you worry that doubling CO2 could cause a 1.1 or thereabouts degree C increase in global mean temperature but are not all concerned that natural forces can cause a 5.0 degree increase or a 10.0 degree decrease.

[Exusian]

"The mere fact that CO2 has been monotonically increasing over the last 150 years and the temperatures have not is proof that the natural variations in the system can and will dominate CO2 concentration increase, whether it is of human origin or not."

Gee, isn't that exactly what I said?
Pray tell, NL, where's the denial?

[Exusian]

And then NL pulls some numbers literally out of a hat.

NL's climate sensitivity to a doubling of CO2 of 1.1C is for CO2 alone, NOT including any warming from any natural feedbacks to the 1.1C increase, such as the resulting lowering of albedo, or increase in atmospheric water vapour, or amplifying emissions from natural carbon sinks. These feedbacks would boost that 1.1C to between 2C and 4.5C, with best estimates being 2.5C to 3C, REGARDLESS of the cause of that initial 1.1C, be it rising CO2, or a brighter sun, or galactic cosmic rays, or the tooth fairy. That's why global warming/climate change deniers/he­cklers/obf­uscators don't like to talk about the feedbacks: they have to account for them in any alternative explanation of their own that they come up with.

As for NL's -10C to +5C temperature change from today due to natural variability, sure, if you consider the difference between Snowball Earth and the Cretaceous hot house. You only have to compare the last glaciation 20000 years ago with today to see a difference of 6C.
Funny, NL doesn't like it when other people refer to paleoclimate events, though.
Too "alarmist."

Oh, did you find your missing argon yet, NL?

[Exusian]

....continued

Sun spots still cycle from maximum to minimum, and the current minimum has been particularly quiet and long-lived. But again, the sun spot cycle is not strictly periodic and it is not possible to predict the length of a sun spot cycle or its intensity with any accuracy.

That's why the long term trend in climate can only be determined after sufficiently long observation. The agreed upon period is 30 years because it takes that long for the underlying climate trend "signal" to emerge from the day-to-day, year-to-year, and decade-to-decade natural variation of weather "noise."

So, yes it's colder now, and the upward trend seems to have halted and reversed, but only time will tell if the trend has actually reversed, or if it has only temporarily been masked by natural variability.

[Hunffingtongreen]

It wasn't so warm when glaciers covered the earth.

It's warmer now.

Socialist have already told us they will promote global warming as a tool to take down the economies of the west and promote socialism.

Gore says they can win the day by brainwashing our children.

Sigh. When did the left become the Totalitarian leftists?

[javaman]

So Tell me, Huffingtongreen, exactly how long have you been off your meds?

[UbiVeritas]

He's just not drinking the socialist kool-aid. You ought to try drinking less of it -- might clear your head.

[Exusian]

The flaw in this argument is that a so-called socialist workers paradise will do nothing to halt global warming.

[NL207]

Precisely what WILL the left do to 'halt global warming'??

I think nothing. The Kyoto Protocol was a product of leftist ideology with the stated goal of reducing global warming and it did NOTHING to halt global warming. It instead was aimed at redistributing wealth on a global scale.

[Exusian]

As long as global warming/climate change is framed as a left vs right political issue rather than as a scientific issue nothing much constructive and substantive is likely to be done, which will suite some people just fine, which is precisely why they continue to frame it as a left vs right political issue.

You were saying, NL?

[NoSillyName]

You must get your "scientific" information from Rush.

[UbiVeritas]

"Cloud-coo­-koo-denie­r land"? Is spelling optional for AGW kool-aid drinkers???

Listen, you can believe the hoax and worship at the Al Gore Temple of gloom and doom. Cut your emissions and shrink your global footprint. Meanwhile Al will continue to jet around the world and live in a 20,000 square foot house, requiring a dedicated coal-fired power plant just to keep him and Tipper comfy. Obama will keep the White House at a balmy 80 degrees so he can pretend he's still in Hawaii and can begin to enjoy the fruits of global warming well before it hits.

It's your faith-based world -- enjoy it!

[javaman]

and when did you get the fox news propaganda chip installed in your head?

[Exusian]

When they shift to using language like "AGW kool-aid drinkers" and "worship at the Al Gore Temple" you know they have no science to argue with.

But then, they never did. Science is not something they understand, and it never will be.

[NL207]

" Science is not something they understand, and it never will be"

You have demonstrated in your posts on this thread that this statement applies to you.

[Exusian]

Oh, you cut to the quick, NL.

Not.

[realpolitic]

NL's posts are getting more and more desperate. She has not made any sense in quite some time!

[shockmagog]

"It's your faith-based world..."
Project this much at home?

"Cut your emissions and shrink your global footprint." Is a good point. So why do so you seem so deadset against it?

Citing extraneous and irrelevant examples is not a way to support such a good nugget of advice embedded in your otherwise nonsensical post.

[Exusian]

Meanwhile, for those living in the reality-based world,
(as opposed to cloud-coo-koo denier land)

Current Arctic winter sea ice recovery extent is pacing 2007-2008, well below the 1979-2000 average.
http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png

So much for that matching 1979 nonsense.

While current summer Antarctic sea ice melt is on-track to set a new record low:
http://nsidc.org/data/seaice_index/images//daily_images/S_timeseries.png

So much for the "yeah, but Antarctica is cooling" nonsense.

[NL207]

Your intellectual dishonesty is at times breathtaking. The winter Anarctic Ice 'anomaly' is at its greatest extent in years:

http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.anom.south.jpg

So much for your cherry picked arguments.

[realpolitic]

Your chart shows the highest sea ice anomalies being found in the last two years.

[shockmagog]

Wow, I can "cherry pick" too. To wit:

'Some climate sceptics point to the differing trends at the poles as a sign that worries about climate change are exaggerated, but experts say they can explain the development.'

'"What's happening is not unexpected­...Climate modellers predicted a long time ago that the Arctic would warm fastest and the Antarctic would be stable for a long time," says Ted Maksym, a sea ice specialist at the British Antarctic Survey.'
http://www.newscientist.com/article/dn14724-antarctic-sea-ice-increases-despite-warming.html

[NL207]

They also predicted that the earth would be warming at an average rate of ~0.33 degrees C per decade over the last 20 years and they were wrong.

[Exusian]

I didn't cherry-pick anything. I merely provided links to the current sea ice extent in both the Arctic and Antarctic. I even labeled them as such.

When it comes to intellectual dishonesty you're the champ, NL.

[UbiVeritas]

Changes in sea ice do not prove that adding more CO2 will increase global warming. Try staying on point -- you'll find it ever so much more satisfying.

[Exusian]

Hows the experiment I assigned you for homework coming Veritas?
http://www.espere.net/Unitedkingdom/water/uk_watexpgreenhouse.htm

When you're finished, then we'll have something to talk about.

[Exusian]

BTW, Veritas, I apologize for my personal comments toward you yesterday. They are inexcusable. I should not post while nursing the flu as it makes one grumpy, irritable and impatient.

[NL207]

You can't even seem to attach your 'B' team comments to the right post. Why would anyone asssume you know anything about science?

[Exusian]

Stooping to petty sniping now, NL?

You must be running dry.

Oh, found the missing argon yet?

[Gildersleeve]

I encourage thinking about how we think about science.
think of the word itself, science (latin sciens -entis)
consider the history of philosophy,
consider the philosophy of history
consider the implications of "science".

what is science? we speak of science in many ways.
how did/does/should science inform our politics?

what sort of worldview does modern technological science inform?
is "truth" simply limited to quantifiability with our human apparatus?

these are serious questions that shape the way we understand this debate.

to quote Bob Dylan:

"and something is happening
but you don't know what it is"

[markinaz]

Can't understand why people argue over this . There are only 3 things anyone needs to know about "global warming". 1; If it exists and humankind is a contributer to it, fine. We cannot change the past. As much as people the world over try to convince others about the validity of their arguments, they are somewhat wasting their time worrying about the future. Mankind will never give up their fossil fuel addiction. Doomsaying the future will not get anyone to give up their precious oil and gas as long as it provides comfort and ease to the daily grind of the masses. Most only care about the here and now, not some unknowable time frame ahead. Add to that the overwhelming influence that the entire industry exerts on the political realm the world over and one can see the near futility of being an environmentalist "tilting at windmills". Do not be under any illusions that alternative sources of energy will ever become "the norm" until every barrel of oil on the planet is extracted form the ground. The social and political systems of the world are geared to a fossil fuel economy and only through radical change will that end. 2; if you are so concerned about the sea level rise that may happen, start making plans now to relocate inland. 3; convince all the naysayers that beachfront property is the way to go and if sea levels do rise, show them all the compassion they deserve.

[csavage]

Don't be so hard on the neo-cons, guys....that home schooling only goes so far...

[UbiVeritas]

And I could go on and on, but why?

The science is not settled. People with a financial interest in AGW WANT you to think the science is settled so you follow blindly where they want to lead you -- talk about "Sheeple" -- Baaaaa

[Exusian]

Exactly, why?

What exactly is the point of quoting from Senator "I never saw an energy industry contribution I wouldn't accept" Inhofe's bogus, fraudulent list of 1) retired and dead people, 2) non-scientists, 3) those with padded resumes that make them sound more educated and qualified than they actually are, 4) actual scientists in some field but with no expertise or qualifications to comment on any aspect of climate science, 5) actual climate scientists who's words have been twisted and taken out of context to make it sound like they do not support the scientific consensus when in fact they actually do?*
(*Multiple examples of each of these instances have been repeatedly documented.)

These lists are nothing but appeals to bogus and fraudulent authority.
They demonstrate nothing about the prevailing scientific consensus, but plenty about the willingness of those who compile them to misrepresent, twist, invent, make stuff up and outright lie to further their agenda, which is to dupe and mislead the ignorant and gullible in order to forestall any meaningful action to address the cause of global warming/climate change, namely burning fossil-carbon fuels.

Where is the truth, indeed?
It's quite clear that Ubi Veritas wouldn't know the truth, or its opposite, if they tripped over it. Which they have.

[UbiVeritas]

Since you won't accept the inconvenient truth of a lack of scientific consensus on AGW, maybe you can answer the following question:

What evidence exists to prove that adding more CO2 to current levels will increase global temperatures substantially?

Please provide evidence. Anything else will just be more of your BS.

[Exusian]

It is you who will not accept the scientific consensus and who pedals pure, unadulterated bs.

I outlined the evidence just down thread. I suggest that you do your own homework to understand the radiative physics of CO2 and the science of global warming/climate change.

Here's a good place to start:
The Discovery of Global Warming, by Dr. Spencer Weart

It's available for free on the American Institute of Physics website:
http://www.aip.org/history/climate/index.html

I also highly recommend Dr. David Archer's
Global warming: Understanding the Forecast
http://www.realclimate.org/index.php/archives/2008/01/our-books/#Archer06

and Dr Archer's
The Long Thaw: How Humans are Changing the Next 100,000 Years of Earth's Climate
http://www.realclimate.org/index.php/archives/2008/01/our-books/#Archer09

[Exusian]

You want more evidence that adding more CO2 to current levels will increase global temperatures substantially?

Venus.
It's mean surface temperature should be 240C/464F due to sunlight alone (blackbody temperature), but instead it is just under 462C/864F due to CO2 making up around 96% of it's atmosphere at a pressure 92 times that of Earth.

Say hello to the greenhouse effect. And so much for the "saturation" argument.

More?
In the deep past Earth's average surface temperature has been much higher than it is today, despite the sun being as much as 25% weaker. For example, 200 million years ago Earth's surface temperature was 6C hotter. What provided the extra heat? Oh, right, 200 million years ago CO2 was as high as 2000 ppmv verses the current level of 387 ppmv.

More?
Look up the Paleocene-Eocene Thermal Maximum, or the Permian-Triassic Extinction Event.

Bottom line: We know adding more CO2 will make it hotter because it has happened before.

[Gildersleeve]

no doubt big financial interests want you to get on board with whatever they're selling.
be it "going green", "eco-friendly" or "global warming" or "climate crisis"

but there is also another sort of grassroots democratic decentralized anti-corpo­ratization­-of-the-gl­obe sort of movement that is a dynamic in "global warming", which I like.

so i guess i am saying,
wherein lies the danger
therein grow the saving power also...

when it comes to predicting the future it's not clear if it is ever "settled"
augurs usually have the same luck as scientists do in that regard.

[Exusian]

Exactly, why?

What exactly is the point of quoting from Senator "I never saw an energy industry contribution I wouldn't accept" Inhofe's bogus, fraudulent list of 1) retired and dead people, 2) non-scientists, 3) those with padded resumes that make them sound more educated and qualified than they actually are, 4) actual scientists in some field but with no expertise or qualifications to comment on any aspect of climate science, 5) actual climate scientists who's words have been twisted and taken out of context to make it sound like they do not support the scientific consensus when in fact they actually do?*
(*Multiple examples of each of these instances have been repeatedly documented.)

These lists are nothing but appeals to bogus and fraudulent authority.
They demonstrate nothing about the prevailing scientific consensus, but plenty about the willingness of those who compile them to misrepresent, twist, invent, make stuff up and outright lie to further their agenda, which is to dupe and mislead the ignorant and gullible in order to forestall any meaningful action to address the cause of global warming/climate change, namely burning fossil-carbon fuels.

Where is the truth, indeed?

It's quite clear that Ubi Veritas wouldn't know the truth, or its opposite, if they tripped over it. Which they have.

[NL207]

Let's try your case 5 out for a test drive: example:

Dr, Christopher Landsea, who resigned from the IPCC because HIS work was being distorted and falsely reported by ... Dr. Kevin Trenberth.

http://www.climatechangefacts.info/ClimateChangeDocuments/LandseaResignationLetterFromIPCC.htm

This Kevin Trenberth:

http://en.wikipedia.org/wiki/Kevin_E._Trenberth

One of your climatologists, if I am not mistaken. Landsea, one of, if not the leading expert in this world on Hurricanes has in effect, described this 'leading climatologist' as an intellectual thug.

I don't think you would know scientific truth if it hit you over the head.

[Exusian]

Yes, there certainly has been friction between Dr. Landsea and Dr. Trenberth, and Landsea certainly did resign from the IPCC over it. This is not news, it was quite public.

But it has nothing what ever to do with my assertion that Senator Inhofe's fraudulent list deliberately takes the words of actual climate scientists out of context and twists them to make it sound like they do not support the scientific consensus when in fact they actually do.

Nice try at distraction, though.

[realpolitic]

Well, it is much easier for denialists to point to a fradulent list of names to bolster their weak arguments then to actually try to read some of the science or even newspaper reports of the science.

[UbiVeritas]

Whaddya know? There's more!!

“Even doubling or tripling the amount of carbon dioxide will virtually have little impact, as water vapour and water condensed on particles as clouds dominate the worldwide scene and always will.” – . Geoffrey G. Duffy, a professor in the Department of Chemical and Materials Engineering of the University of Auckland, NZ.

“After reading [UN IPCC chairman] Pachauri's asinine comment [comparing skeptics to] Flat Earthers, it's hard to remain quiet.” - Climate statistician Dr. William M. Briggs, who specializes in the statistics of forecast evaluation, serves on the American Meteorological Society's Probability and Statistics Committee and is an Associate Editor of Monthly Weather Review.

“For how many years must the planet cool before we begin to understand that the planet is not warming? For how many years must cooling go on?" - Geologist Dr. David Gee the chairman of the science committee of the 2008 International Geological Congress who has authored 130 plus peer reviewed papers, and is currently at Uppsala University in Sweden.

[UbiVeritas]

More evidence

“The IPCC has actually become a closed circuit; it doesn’t listen to others. It doesn’t have open minds… I am really amazed that the Nobel Peace Prize has been given on scientifically incorrect conclusions by people who are not geologists,” - Indian geologist Dr. Arun D. Ahluwalia at Punjab University and a board member of the UN-supported International Year of the Planet.

“The models and forecasts of the UN IPCC "are incorrect because they only are based on mathematical models and presented results at scenarios that do not include, for example, solar activity.” - Victor Manuel Velasco Herrera, a researcher at the Institute of Geophysics of the National Autonomous University of Mexico

“It is a blatant lie put forth in the media that makes it seem there is only a fringe of scientists who don’t buy into anthropogenic global warming.” - U.S Government Atmospheric Scientist Stanley B. Goldenberg of the Hurricane Research Division of NOAA.

[UbiVeritas]

evidence that the "science is not settled"

“I am a skeptic…Global warming has become a new religion.” - Nobel Prize Winner for Physics, Ivar Giaever.

“Since I am no longer affiliated with any organization nor receiving any funding, I can speak quite frankly….As a scientist I remain skeptical.” - Atmospheric Scientist Dr. Joanne Simpson, the first woman in the world to receive a PhD in meteorology and formerly of NASA who has authored more than 190 studies and has been called “among the most preeminent scientists of the last 100 years.”

Warming fears are the “worst scientific scandal in the history…When people come to know what the truth is, they will feel deceived by science and scientists.” - UN IPCC Japanese Scientist Dr. Kiminori Itoh, an award-winning PhD environmental physical chemist.

It's interesting that former IPCC contributors are now openly skeptical of AGW.

[gino618]

What's the purpose of this story? The author is hypothesizing a 'what would happen if' , but admits that the 'if' is just that... there's no claim that the 'if' is happening now or anytime predictably within the future?

This is no different that 'What if a meteor strikes the earth?' or 'What if a dinosaur appeared?'

Pure speculation based on imagination.

[publicmenace]

Anybody else notice that the wingnutz have two different but contradictory arguments against climate change?

Argument A: There is no evidence of global warming.

Argument B: There is no evidence that humans cause global warming.

Huh? Now that's what I call a logical disconnect.

[ToxicAdam]

You throw out a lot of generalizations.


It would be very rare to see someone say "there is no global warming". We are in a natural cycle of warming. That is undeniable.

To your second part, there is no proof that humans are the *main* driving force of the warming we have seen in the past 20 years. I think most AGW-deniers realize that we are contributing (even some prominent EVIL neo-cons you seem to hate) to the problem, but do not think we are the main cause.

..and yes, there is no "smoking gun" that proves humans are the main culprit for the rate of warming to increase over a very short time span. That's why the activists and the media have stepped in to indoctrinate us with the ideas of an "overwhelming consensus" and other such things.

[dm10003]

it's like those who don't believe that adam, eve, and eden really existed but they still believe in original sin.

[gino618]

You're assuming that the same people have the same 2 arguments - a false premise. There are varying scales of argumentative discourse - those who believe 100% in man-made global warming, to those who do not believe there is any global warming - and varying degrees within that framework.

And those variations are on BOTH sides of the political aisle. To limit the anti-climate change views to the right wing of the political spectrum ignores regular polling data which shows a shift away from believing in man-made effects to the current point where the majority believe that position to be overstated.

[wmfor]

One more common argument: It's been really cold this winter.

[topgunna]

The anthropogenic global warming theory is a logic chain - a series of several hypotheses that build off one another. The theory is only as strong as the weakest link.

1) Is the globe warming?
2) Are humans causing it?
3) Are the net consequences negative or positive?
4) If it is bad, can we stop it?
5) Does a thoughtful cost/benefit analysis warrant the action necessary to stop it?

Logic step one is settled science - the temperature record reflects a warmer world since the early 1900s. Beyond that, everything is projections and backfitting theories to explain data trends.

[Exusian]

Not at all.

2 can be shown by the fact that humans are responsible for 200% of the increase in CO2. Since CO2 is a greenhouse gas is also settled science, that increase must be responsible for some portion of the warming. You can question how much, but you're going to have to come up with another source of the right magnitude to make up the difference. And it's not like people haven't been looking.

3, the negative and positive consequences, can be limited by what past warming has produced. For example, the fact that the Antarctic Ice cap did not melt entirely during any of the past interglacials means it's not likely to happen during this one, while the Younger Dryas and the droughts of the Holocene Climate Optimum of 8000 years ago show us how fast climate can change and literally wipe out established civilizations and agriculture. The computer models are also all about finding the limits of potential change. Change of unknown magnitude is the the ultimate risk.

4, if we wait until it gets bad there will be no way that we can stop it, because "bad" will be when natural feedbacks equal or exceed our own emissions.

5 ties back into 3 and 4. The more that is unknown, the higher the risk, and the longer we wait, the higher the cost and the less likelihood of success.