AGW Skepticism and Rationale (Warning: Long)

100 bucks says he claims the NAS is in Exxon's pocket.



Performing your original search, national academy of sciences global warming, in Science will retrieve 429 results.

Science 3 December 2004:
Vol. 306. no. 5702, p. 1686
DOI: 10.1126/science.1103618
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Essays on Science and Society
Also see the archival list of the Essays on Science and Society.
BEYOND THE IVORY TOWER:
The Scientific Consensus on Climate Change
Naomi Oreskes*
Policy-makers and the media, particularly in the United States, frequently assert that climate science is highly uncertain. Some have used this as an argument against adopting strong measures to reduce greenhouse gas emissions. For example, while discussing a major U.S. Environmental Protection Agency report on the risks of climate change, then-EPA administrator Christine Whitman argued, "As [the report] went through review, there was less consensus on the science and conclusions on climate change" (1). Some corporations whose revenues might be adversely affected by controls on carbon dioxide emissions have also alleged major uncertainties in the science (2). Such statements suggest that there might be substantive disagreement in the scientific community about the reality of anthropogenic climate change. This is not the case.

The scientific consensus is clearly expressed in the reports of the Intergovernmental Panel on Climate Change (IPCC). Created in 1988 by the World Meteorological Organization and the United Nations Environmental Programme, IPCC's purpose is to evaluate the state of climate science as a basis for informed policy action, primarily on the basis of peer-reviewed and published scientific literature (3). In its most recent assessment, IPCC states unequivocally that the consensus of scientific opinion is that Earth's climate is being affected by human activities: "Human activities ... are modifying the concentration of atmospheric constituents ... that absorb or scatter radiant energy. ... [M]ost of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations" [p. 21 in (4)].

IPCC is not alone in its conclusions. In recent years, all major scientific bodies in the United States whose members' expertise bears directly on the matter have issued similar statements. For example, the National Academy of Sciences report, Climate Change Science: An Analysis of Some Key Questions, begins: "Greenhouse gases are accumulating in Earth's atmosphere as a result of human activities, causing surface air temperatures and subsurface ocean temperatures to rise" [p. 1 in (5)]. The report explicitly asks whether the IPCC assessment is a fair summary of professional scientific thinking, and answers yes: "The IPCC's conclusion that most of the observed warming of the last 50 years is likely to have been due to the increase in greenhouse gas concentrations accurately reflects the current thinking of the scientific community on this issue" [p. 3 in (5)].

Others agree. The American Meteorological Society (6), the American Geophysical Union (7), and the American Association for the Advancement of Science (AAAS) all have issued statements in recent years concluding that the evidence for human modification of climate is compelling (8).
 
100 bucks says he claims the NAS is in Exxon's pocket.

The President of the National Academy of Sciences on global warming.....



[ame=http://www.youtube.com/watch?v=WHEQRUc-AYo]YouTube - President of National Academy of Sciences on Global Warming[/ame]
 
Who is they? I personally have never denied it is happening. Where I start to question it is how much is caused by Humans, and how much we can actually do to stop it.

Yeah, Charles.

This is a problem that we all have, I think, and generally I think it a problem without malice.

We generalize and tend to make every issue TWO sided.

Obviously the span of opinion is vast and so we ALL tend to argue with some mythical radical who we can't identify, because it is a composite straw man of our own inventions.

We need to start giving each other a break, folks.

We can do this, you know. If enough of us stop looking for people to beat up, maybe we can teach each other things that we're NEVER going to learn from the people who we already agree with.

the "Opposing" viewpoint van often be your best teacher, if you give 'em half a chance to discuss things rationally.
 
Speaking of reading comprehension, here is a quote from the article....

"The scientific academies of 13 countries on Tuesday urged the world to act more forcefully to limit the threat posed by human-driven global warming."

"In a joint statement, the academies of the Group of 8 industrialized countries — Britain, Canada, France, Germany, Italy, Japan, Russia and the United States — and of Brazil, China, India, Mexico and South Africa called on the industrialized countries to lead a “transition to a low-carbon society” and aggressively move to limit impacts from changes in climate that are already under way and impossible to stop."

"The statement, posted by the National Academy of Sciences in the United States, urged the Group of 8 countries to move beyond last year’s pledge to consider halving global emissions of greenhouse gases by 2050 and “make maximum efforts” to reach this target. "

You do realize that the national academies of science represent the scientists is all of these 13 countries, don't you?

Which again does not state in any way that man is the predominant cause of the current warming trend.
 
No? "...human-driven global warming"? Is that not it?

No it isn't. You are makeing the false conclusion that since they are saying we should curb greenhouse emmissions they must also be saying we are the predominant cause of the warmiing trend.

I have yet to see any scientific evidence that bears that out. TopGunna was kind enough to post some scientific evidence the may dispute it. But really all I hear on these boards anyway is that 'all the scientists agree' (which more often then not turns out to be referring to the IPCC which is also not worth the paper it's written on). I have to hear or see an actual scientific explanation as to how we have caused the bulk of the warming we are currently seeing.
 
No it isn't. You are makeing the false conclusion that since they are saying we should curb greenhouse emmissions they must also be saying we are the predominant cause of the warmiing trend.

I have yet to see any scientific evidence that bears that out. TopGunna was kind enough to post some scientific evidence the may dispute it. But really all I hear on these boards anyway is that 'all the scientists agree' (which more often then not turns out to be referring to the IPCC which is also not worth the paper it's written on). I have to hear or see an actual scientific explanation as to how we have caused the bulk of the warming we are currently seeing.

But you wrote:

Which again does not state in any way that man is the predominant cause of the current warming trend.

Yet the quoted piece said, inter alia:

"The scientific academies of 13 countries on Tuesday urged the world to act more forcefully to limit the threat posed by human-driven global warming."

That was my point.
 
No it isn't. You are makeing the false conclusion that since they are saying we should curb greenhouse emmissions they must also be saying we are the predominant cause of the warmiing trend.

I have yet to see any scientific evidence that bears that out. TopGunna was kind enough to post some scientific evidence the may dispute it. But really all I hear on these boards anyway is that 'all the scientists agree' (which more often then not turns out to be referring to the IPCC which is also not worth the paper it's written on). I have to hear or see an actual scientific explanation as to how we have caused the bulk of the warming we are currently seeing.

CO2 causes the earth to warm.

We are pumping 8 billion metric tons of CO2 into the atmosphere every year, and that amount is accelerating.

The amount of CO2 in the atmosphere has increased by one third in the last 200 years.

CO2 is now at the highest level ever recorded, and the Antarctic ice core record goes back 600,000 years.

Therefore, we are warming the earth.
 
CO2 causes the earth to warm.

We are pumping 8 billion metric tons of CO2 into the atmosphere every year, and that amount is accelerating.

The amount of CO2 in the atmosphere has increased by one third in the last 200 years.

CO2 is now at the highest level ever recorded, and the Antarctic ice core record goes back 600,000 years.

Therefore, we are warming the earth.

Your science is truly breathtaking. I refer you to the orginal post in this thread as to the percentage of the atmosphere that is actually CO2. Due to the very low percentage of Co2 that makes up the total atmosphere, for the warming trend to be currently caused by us this increase in Co2 would have to be haveing a truly exponential effect on warming and that hasn't been shown to be the case.
 
But you wrote:



Yet the quoted piece said, inter alia:



That was my point.

You said:

"The scientific academies of 13 countries on Tuesday urged the world to act more forcefully to limit the threat posed by human-driven global warming."

No? "...human-driven global warming"? Is that not it?

I stated the article does not state that there is a consensus that man is the predominant cause of the warming trend. To which you seem to have pointed to the above statement in thinking that it actually does say that. Again, it doesn't.
 
Editec, I'm going to group some of your quotes together, since some of your questions (good ones at that) can be addressed with the same answer.

You are basing your trends on what, exactly? Intuition or something?...
Hard to respond to that rationally because it's all over the map. But yes there are national climatic changes to be sure. Some huge and remain for a long time vast and some don't last so long. Nobody disputes this and everybody knows it, too...

My 100 year trend was based on the following data. Coincidentally, it's the same data Michael Mann used in his Hockey Stick graph:

temperatureline.jpg


And the recent 8 year trend is based on the below data (from Satellites, so the record doesn't go back nearly as far):

rss_may_08520.png


My point was that you can interpret the same data any number of ways; it all depends on how you frame the data set. 2008 is colder than 1998, but it's warmer than 1990. So it's perfectly logical to suggest we're in a 10 year cooling trend or a 20 year warming trend. Both are correct.

No, but you asserted that as a fact.
I'm not the one who made the assertion. I'm using the data from Mann, who uses the 100 year, .6 Centrigrade temperature increase to promote AGW theory. Which, as you can see in his now famous Hockey Stick graph:
image008.jpg


This is a strawman, you know.. Nobody I have ever read suggested that the "the climate was virtually static before man intervened"

You mistate the argument for global warming, you know.
What they are saying is that the RATE OF CHANGE is highly unusual.

That seems to be the very implication of Mann’s graph – that temperatures were extremely stable over the past 1,000 years until the onset of the industrial revolution, which he claims caused a sharp temperature spike over the past 100 years.

As recently as 1990, the IPCC used this graph to explain the climate of the past 1,000 years.

image007.jpg


When developing the Hockey Stick graph, Mann chose to reconstruct the 1,000 year temperature trend using his own proxy data, rather than the above graph (which incidentally, was the previous consensus in the climate science community). His data showed temperature variation as being extremely flat; gone was the Medieval Warm Period and Little Ice Age.

The temperatures we’ve recorded since 1880 aren’t really the key in my argument. I accept the AGW claim that temperatures have increased by .6 degrees over the past century, as the measured temperature record reflects this increase. But it’s my belief that this temperature increase isn’t that unusual – it only looks unusual when you construct a 1,000 year temperature record with an extremely flat slope.

But mankind CAN establish with a high degree of certainty what the earts temperature was for the last 600,000 years. ARe you aware of this? Or do you join others in not believing in that science?

I don’t believe there is a high degree of certainty. We do have proxy data like Antarctic ice cores that we can use to approximate historic local temperatures, but we only have a baseline of 40-50 years of measured data to validate the proxy. Ice core data has been shown to correlate with measured Antarctic temperatures over those 40some years, but not perfectly. You can extrapolate that imperfect correlation as far as you like to approximate temperatures, but in essence you’re using 40 years of known data to approximate 600,000. Even if the data sets correlate with a 99.9% degree of certainty, there’s only a 22% certainty that you can accurately reconstruct temperatures, because any slight disconnect gets compounded 1,500 times!

Even if climate scientists could identify a temperature proxy that correlates perfectly with local temperatures, is the Antarctic climate really that indicative of the rest of the planet? Antarctica temperatures have been dropping since we’ve began measuring them, which makes it an anomaly compared to the global trend. I find it incredible that people trust the historic explanatory power of a region that so very poorly reflects present conditions.

Now you are assuming that CO2 levels are all that are driving global warming, and that a 1.2 degree centigrate change will not trigger other events which ALSO cause GW.
True, because that’s the claim of AGW alarmists, that CO2 concentrations are the ignition to a chain of warming events.

Okay, not doubt increased temperature leads to increased H2O loading in the atmosphere….It is THEORY that warmer air can hold more water vapor? Hmmm...I don't think so. I think that is easily proven and well known.

I actually do believe that warmer temperatures increase atmospheric water vapor. But it is impossible to quantify since water vapor is not uniformly distributed in the atmosphere (CO2, on the other hand, mixes into the atmosphere fairly quickly and uniformly). So any estimate for the amount of water vapor spurred by higher CO2 concentrations is theoretical. There are empirical studies that validate the negative feedbacks, though, but the climate models that produce doomsday scenarios tend to ignore these and assume that the water vapor feedback is greater, and more important. That’s what I take exception to.

Huh? You lost me there. You above argument just went into proxisms to PROVE TO US THAT THE CLIMATE IS NOT A LONG-TERM STABILE SYSTEM.

I probably wasn’t clear on this… but I believe the Earth’s climate responds to forcings through negative feedbacks. The best analogy I can give you is to consider a golf ball sitting in a bowl. You can flick the golf ball any direction, but friction, gravity and the shape of the bowl will tend to force the ball back to its original position. As such, a system governed by negative feedback will tend to return to its equilibrium state, even though forcings can push the system any number of directions.

A system governed by positive feedback, on the other hand, is analogous to a golf ball sitting on top of a bowl (turned upside down). A slight force on the golf ball will cause the ball to accelerate that direction as it rolls down the bowl, until it eventually settles in a new point, far from its starting point. Even then, the system is only stable until the next slight forcing comes along. Systems governed by positive feedback are extremely unstable over the long-term, and as such, naturally occurring systems governed by positive feedback are extremely rare.

In essence, I believe that the Earth’s climate is governed by negative feedbacks that allow for fluctuations into and out of ice ages, just as the golf ball rolls around in the bowl. The climate is never perfectly static, as heat is constantly radiated from the sun, so the golf ball never quite settles. But it’s always in range of that equilibrium point, even as it is responding to countless forcings – that’s what I mean by long-term stable.

I don't think you really understand the Cretaseous period as well as you think you do.

Quite possibly, I don’t. My point was that even under the extreme conditions of the period, the world’s climate tended back towards the more comfortable equilibrium point (temperatures did not run-away, turning the Earth into Venus).

Good questions, and obviously I don’t know everything. Still, I would like to see some of the seeming paradoxes I’ve identified resolved, before I willingly accept the AGW theory. I need more than anecdotal evidence of forest fires and droughts – the world is a big place, and extreme weather will almost certainly be occurring somewhere on the globe.
 
You said:



I stated the article does not state that there is a consensus that man is the predominant cause of the warming trend. To which you seem to have pointed to the above statement in thinking that it actually does say that. Again, it doesn't.

Sorry, yes it does. The academies represent the scientists in all those 13 countries. The consensus is there. You will not admit it because it does not fit your world view.
 
Your science is truly breathtaking. I refer you to the orginal post in this thread as to the percentage of the atmosphere that is actually CO2. Due to the very low percentage of Co2 that makes up the total atmosphere, for the warming trend to be currently caused by us this increase in Co2 would have to be haveing a truly exponential effect on warming and that hasn't been shown to be the case.

Increasing the CO2 in the atmosphere by one third in 200 years is a huge change, and we are going to double the amount of CO2 in the next 20 years.

CO2 warms the earth. That is not in dispute. You say it doesn't warm it much. The climatologists disagree with you.
 
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Increasing the CO2 in the atmosphere by one third in 200 years is a huge change, and we are going to double the amount of CO2 in the next 20 years.

CO2 warms the earth. That is not in dispute. You say it doesn't warm it much. The climatologists disagree with you.

Co2 is a known heat trapper. No one is arguing that.

Show me some hard evidence that an increase in CO2 (a relatively insignificant component of the atmosphere) has predominantly contributed to the current warming trend. Yes a 1/3 increase does seem large, but taken as part of the entire atmosphere it is .03 percent. Now were maybe at .04% and you want to claim that has been the predominant driver of the warming trend? I'm no scientist but that doesn't sound real logical to me.
 
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Sorry, yes it does. The academies represent the scientists in all those 13 countries. The consensus is there. You will not admit it because it does not fit your world view.

No. It says we should curb greenhouse gas emmissions. How that is the same thing as saying most scientists agree man is the predominant cause of global warming, I'm not sure.
 
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Co2 is a know heat trapper. No one is arguing effect.

Show me some hard evidence that an increase in CO2 (a relatively insignificant component of the atmosphere) has predominantly contributed to the current warming trend.

Um last time I check the so called experts were saying CO2 could double, not that it would. Note that most of the scarier climate models all assume that it for sure will double, when that is by no means a certainty.
 

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