Posted on 06/22/2006 8:28:41 AM PDT by Semus Dynnen
Study Says Earth's Temp at 400-Year High Jun 22 11:10 AM US/Eastern
By JOHN HEILPRIN Associated Press Writer
WASHINGTON
The Earth is the hottest it has been in at least 400 years, probably even longer. The National Academy of Sciences, reaching that conclusion in a broad review of scientific work requested by Congress, reported Thursday that the "recent warmth is unprecedented for at least the last 400 years and potentially the last several millennia."
A panel of top climate scientists told lawmakers that the Earth is running a fever and that "human activities are responsible for much of the recent warming." Their 155-page report said average global surface temperatures in the Northern Hemisphere rose about 1 degree during the 20th century.
The report was requested in November by the chairman of the House Science Committee, Rep. Sherwood Boehlert, R-N.Y., to address naysayers who question whether global warming is a major threat.
Last year, when the House Energy and Commerce Committee chairman, Rep. Joe Barton, R-Texas, launched an investigation of three climate scientists, Boehlert said Barton should try to learn from scientists, not intimidate them.
The Bush administration also has maintained that the threat is not severe enough to warrant new pollution controls that the White House says would have cost 5 million Americans their jobs.
Climate scientists Michael Mann, Raymond Bradley and Malcolm Hughes had concluded the Northern Hemisphere was the warmest it has been in 2,000 years. Their research was known as the "hockey-stick" graphic because it compared the sharp curve of the hockey blade to the recent uptick in temperatures and the stick's long shaft to centuries of previous climate stability.
The National Academy scientists concluded that the Mann-Bradley-Hughes research from the late 1990s was "likely" to be true, said John "Mike" Wallace, an atmospheric sciences professor at the University of Washington and a panel member. The conclusions from the '90s research "are very close to being right" and are supported by even more recent data, Wallace said.
The panel looked at how other scientists reconstructed the Earth's temperatures going back thousands of years, before there was data from modern scientific instruments.
For all but the most recent 150 years, the academy scientists relied on "proxy" evidence from tree rings, corals, glaciers and ice cores, cave deposits, ocean and lake sediments, boreholes and other sources. They also examined indirect records such as paintings of glaciers in the Alps.
Combining that information gave the panel "a high level of confidence that the last few decades of the 20th century were warmer than any comparable period in the last 400 years," the academy said.
Overall, the panel agreed that the warming in the last few decades of the 20th century was unprecedented over the last 1,000 years, though relatively warm conditions persisted around the year 1000, followed by a "Little Ice Age" from about 1500 to 1850.
The scientists said they had less confidence in the evidence of temperatures before 1600. But they considered it reliable enough to conclude there were sharp spikes in carbon dioxide and methane, the two major "greenhouse" gases blamed for trapping heat in the atmosphere, beginning in the 20th century, after remaining fairly level for 12,000 years.
Between 1 A.D. and 1850, volcanic eruptions and solar fluctuations were the main causes of changes in greenhouse gas levels. But those temperature changes "were much less pronounced than the warming due to greenhouse gas" levels by pollution since the mid-19th century, it said.
The National Academy of Sciences is a private organization chartered by Congress to advise the government of scientific matters.
Quick Reaction to the NRC Hockey Stick Report
I actually disagree with the article conclusions; from what I've seen, the report does not at all vindicate Mann et al.'s methods. But the point I'm going to raise with you is the reply from Hans von Storch (and given what you've said, I expect that you recognize the name -- otherwise, Google it).
"Our group (Eduardo Zorita, Fidel Gonzalez-Rouco and myself) have issued this statement: “We welcome the National Research Council’s Report, which clarifies that the discussion about the technical qualities of the hockeystick-methodology is insignificant for the overall conclusion that the presently ongoing warming is likely related to elevated greenhouse gas concentrations in the atmosphere. We are pleased to read that the NRC shares our view that the methodology behind the hockeystick is questionable. We stick to our view that the methodology was not sufficiently described when published and independently tested thereafter.”
On my web-page (http://w3g.gkss.de/staff/storch/Media/NRC-conclusion.hvs+ez.0606.doc) this statement is explained in some more detail. The problem of “detecting” ongoing climate change as (partly) non-natural and “attributing” human causes to this change, is based on the speed of temperature change, i.e, it is mainly an analysis of trends. To this end, the hockey stick was never really relevant, but it was “made” relevant by interested scientists, often detached from the debate about “d&a” (detection and attribution) and the public, who is unable to deal with the intricacies of d&a.
The analysis in Rybski, D., A. Bunde, S. Havlin, and H. von Storch, 2006: Long-term persistence in climate and the detection problem. Geophys. Res. Lett. 33, L06718, doi:10.1029/2005GL02559 examines how the detection effort depends on what we assume the right historical temp reconstruction would be. That is the most recent trend from instrumental data were compared with “historical noise levels” from a series of reconstructions, namely Mann, McIntyre, Esper, Jones and Moberg. In all cases, the result was the same – independently of the assumed temp history of the last 1000 years, the recent changes are beyond the range of historical “evidence” (whichever you chose to opt for).
In my opinion, the significance of the hockeystick debate is not with the question of d&a, but with the scientific culture of openly discussing concepts, of sharing data, of describing methodologies so that third parties, also hostile third parties, can examine the claims."
In my opinion, that clarifies things fairly nicely.
What they are trying to achieve is, CONTROL and POWER.
That's what the "global warming scare" is all about.
The environmentalists, the Greenies, the socialists, the Marxists, KNOW that in the arena of history, socialism is losing and capitalism is winning. They know that Freedom is on the march, and that their ideas are in retreat.
How to reverse this?
To regain control, to regain power, they need to put before the public "scare issues" that present situations so dire, that the public must surrender control to "the government", because the matters-at-hand are too overwhelming to be trusted to the private sector. And, thus, the electorate is persuaded to hand over ever-increasing power to unelected bureaucrats and administrators who will "know what is best for us".
And so we are bombarded with the threat of global climactic change caused by humanity. And we are told the only way to "reverse" it will be to surrender our ecomonies, our futures, and our FREEDOMS.... to THEM.
And the doomsayers get more and more hysterical, as with Gore's warnings that we have but 10 years to "stop" the process of climate change. When, in truth, the earth will go on "changing" as Mother Nature wishes, and the efforts of humans to accelerate or to decelerate such "change" will matter no more than a spit in the wind.
Michael Crichton layed all this out in his timely book, "State of Fear". If anyone reading this far hasn't yet bought that book, I urge you to do so. It's not only informative, but a very easy and good read to boot. It would make a heck of a movie - especially as a counterpoint to Gore's film - but I doubt any of the studios would undertake the project because Mr. Crichton's ideas are so politically incorrect. Mel Gibson, your phone is ringing!
- John
See post 121.
The sunspot cycle is another favorite red herring of theirs. While the current cycle lowers the sun's luminosity, it lowers it minimally. The effect may even be the opposite: http://www.sciencedaily.com/releases/2004/08/040803093903.htm
Mostly I don't like realclimate because they ignore everything I post except to toss me some obfuscations. I now believe I was wrong when I said Mars was warming globally, but other than that, there's not much science at that site that I can agree with.
That's debatable. See my link in post 124.
I think your link seems to leave out the effect of cosmic rays on clouds and climate, but otherwise is a pretty good general overview.
Did RealClimate have a post on this? Not that it matters; I would be interested in how someone could draw meaningful conclusions about solar activity based upon the inferred climate of Pluto.
but the point of showing warming on other planets is to simply to show that warming is not anthropogenic.
Just because other planets have climate variability (which one would think they might) doesn't prove or disprove an anthropogenic influence on climate here on Earth. The only thing I would deem relevant is a clear linkage between solar activity and climate change on other planets. As I've posted previously (just above is the most recent time) solar activity does not explain the current warming trend on Earth. That does not (in any sense) indicate that variability of solar activity is not an important climate influence. It certainly has been and would be expected to be.
but other than that, there's not much science at that site that I can agree with.
If there was only one side to a given issue, debates on that issue would be short and boring.
I'm surprised that you said that the link between reduced solar activity (indicated by sunspot numbers) and the Little Ice Age is debatable -- I thought that was settled. The Maunder Minimum is the most famous low-sunspot period, but there are a couple previous (Spoorer?) during the ~1400-1800 period. I like your link, too, it's similar to mine, with references to Solanki. But though the article indicates that MWP (1100-1250) was related to enhanced solar activity, it didn't say anything about the LIA.
global warming on Triton
global warming on Enceladus
(In case you don't have enough planetary warming links). I agree that warming or cooling on other planets doesn't negate any hypothesis on earth, but it does show that other factors are at work (geological, solar, etc) that can produce quick effects. Solar activity is too complicated to rule out. The luminosity is easy to measure (and shows tiny decreases), but the effect of increases in the sun's magnetic field are not well understood.
The RC site does not have balanced debates by any measure. Several skeptics were kicked off for being rude (they were rude, no doubt about it). Thin-skinned debators are not good ones, that's why it's so nice to have you here!
All correlations from sunspot numbers are debatable because the increase in sunspots causes decreases in luminosity (not debatable, but those are relatively small). However, decreases in sunspots means decreases in MF and therefore increases in cosmic rays which may cause cooling.
In every discussion that I've participated in, I have never tried to manufacture or make up something that wasn't scientifically supported. On occasions when I exhibited less than total recall of something I was trying to remember, my poor memory has been corrected by other parties.
Actually it was hotter in the mid evil warming period. They called it Greenland for a good reason. Although the Greenland icecap was intact, the edges of Greenland in the South were farmed and habitable.
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