CO2 may not warm the planet as much as thought

• 19:00 24 November 2011 by Michael Marshall
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The climate may be less sensitive to carbon dioxide than we thought – and temperature rises this century could be smaller than expected. That's the surprise result of a new analysis of the last ice age. However, the finding comes from considering just one climate model, and unless it can be replicated using other models, researchers are dubious that it is genuine.

As more greenhouse gases enter the atmosphere, more heat is trapped and temperatures go up – but by how much? The best estimates say that if the amount of carbon dioxide in the atmosphere doubles, temperatures will rise by 3 °C. This is the "climate sensitivity".

But the 3 °C figure is only an estimate. In 2007, the Intergovernmental Panel on Climate Change (IPCC) said the climate sensitivity could be anywhere between 2 and 4.5 °C. That means the temperature rise from a given release of carbon dioxide is still uncertain.

There have been several attempts to pin down the sensitivity. The latest comes from Andreas Schmittner of Oregon State University, Corvallis, and colleagues, who took a closer look at the Last Glacial Maximum around 20,000 years ago, when the last ice age was at its height.

Icy cold

They used previously published data to put together a detailed global map of surface temperatures. This showed that the planet was, on average, 2.2 °C cooler than today. We already know from ice cores that greenhouse gas levels in the atmosphere at the time were much lower than they are now.

Schmittner plugged the atmospheric greenhouse gas concentrations that existed during the Last Glacial Maximum into a climate model and tried to recreate the global temperature patterns. He found that he had to assume a relatively small climate sensitivity of 2.4 °C if the model was to give the best fit.

If climate sensitivity really is so low, global warming this century will be at the lower end of the IPCC's estimates. Assuming we keep burning fossil fuels heavily, the IPCC estimates that temperatures will rise about 4 °C by 2100, compared with 1980 to 1999. Schmittner's study suggests the warming would be closer to their minimum estimate for the "heavy burning" scenario, which is 2.4 °C.

Sensitive models

Past climates can help us work out the true climate sensitivity, says Gavin Schmidt of the NASA Goddard Institute of Space Studies in New York City. But he says the results of Schmittner's study aren't strong enough to change his mind about the climate sensitivity. "I don't expect this to impact consensus estimates," he says.

In particular, the model that Schmittner used in his analysis underestimates the cooling in Antarctica and the mid-latitudes. "The model estimate of the cooling during the Last Glacial Maximum is a clear underestimate," Schmidt says. "A different model would give a cooler Last Glacial Maximum, and thus a larger sensitivity."

Schmittner agrees it is too early to draw firm conclusions. Individual climate models all have their own quirks, so he wants to try the experiment with several models to find out if others repeat the result.

Even if the climate sensitivity really is as low as 2.4 °C, Schmittner says that doesn't mean we are safe from climate change. The Last Glacial Maximum was only 2.2 °C cooler than today, yet there were huge ice sheets, plant life was different, and sea levels were 120 metres lower.

"Very small changes in temperature cause huge changes in certain regions," Schmittner says. So even if we get a smaller temperature rise than we expected, the knock-on effects would still be severe.

Journal reference: Science, DOI: 10.1126/science.1203513

http://www.newscientist.com/article/dn21212-co2-may-not-warm-the-planet-as-much-as-thought.html

Global warming or global bias ? You read, you decide.

Here is a chart that seems to make the point for the Warming Alarmists. What goes unasked and unanswered are these questions: does this chart represent a linear equation or is it a close-up taken in the midst of a weather cycle. The former supports the Alarmists, the latter supports the Pragmatists. A second question has to do with the degree of increase. There is no reason for alarm, in this chart, because actaul temps are excluded. Midknight Review has published NASA charts for the United States showing a 130 year temperature increase of 1.5 degrees, Celsius - hardly the warming disaster that has been reported by the "Sky is falling" industry. Understand that without the "crisis" of global warming, there can be no serious Cap and Trade legislation, no tax increases, no forced transfer of wealth on the world stage.

The stated opinion (below) that temps are likely to increase "dramatically" is not a factual statement, but, rather, a reflexion of a particular bias and nothing more. Readers and students need to be careful not to confuse political opinion with scientific fact when viewing publications such as the one below. Such confusion is difficult to avoid when, in this case, a factually based chart is partnered with a politically motivated point of view -- jds.

Record high temperatures far outpace record lows across U.S.

Thursday, February 11th, 2010

Spurred by a warming climate, daily record high temperatures occurred twice as often as record lows over the last decade across the continental United States, new research shows. The ratio of record highs to lows is likely to increase dramatically in coming decades if emissions of greenhouse gases continue to climb.

The key point is that you can’t draw conclusions about the climate from any single weather event, but instead need to do statistical analyses across large regions to understand what is happening.

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Bad News For The Warmers - N.Y. Times Article

Posted by Michael Laprarie Published: January 1, 2009 - 4:15 PM
2008 has been a very frustrating year for everyone, but probably more so for disciples of man-made global warming climate change theories. In fact, Christopher Booker, writing for The Telegraph, went so far as to declare: 2008 was the year man-made global warming was disproved.
"Disproved" is a pretty significant claim, but even if you disagree with Booker's level of certainty you must confess that man-made climate change theories have taken a lot of lumps as of late:
Suddenly it's not "global warming" any more. Nor do we see the term "greenhouse effect" used very often these days. Even "greenhouse gas" has been replaced by the much less specific "CO2 emissions." All of it has been tucked under the generic umbrella of "climate change."

The infamous Bradley-Hughes-Mann "hockey stick" graph, originally based on data collected from the observation of tree rings and which purports to show that global temperatures remained steady for 2000 years before rising significantly during the 20th century, has been extensively studied and found to be massively deficient. You will recall that the "hockey stick" is the fundamental piece of scientific research supporting most of the claims in Al Gore's An Inconvenient Truth.

Dr. James Hansen, who by all indications will be President-Elect Obama's new "climate czar," has also come under fire. Hansen is Director of NASA's presumably non-partisan Goddard Institute for Space Studies (GISS), yet to say that Hansen has been a political agitator would be an understatement. In 2006 he accused NASA, under the influence of the Bush Administration, of deliberately censoring him and trying to stifle public debate on climate change. And in June of this year, he urged criminal trials for the executives of energy companies, claiming that they were "actively spreading doubt about global warming in the same way that tobacco companies blurred the links between smoking and cancer."

But Hansen has been publicly shamed twice in the last two years. First, his widely-repeated claim that 1998 was the hottest year of the 20th century was debunked by the painstaking research of mineralogist and mathematician Stephen McIntyre. (Incidentally, McIntyre and Ross McKitrick published the first extensive criticism of the "hockey stick" graph.) Then in November 2008 Hansen made the astonishing announcement that October 2008 was the warmest month ever measured. This claim was immediately shot down after investigators discovered that much of Hansen's data from Russia and elsewhere were not real measurement data at all, but estimates derived from carrying over previous month's temperatures.
Al Gore is now his own worst enemy. If you scheduled an Al Gore visit in 2008, it was almost a sure bet that your city would also be visited by unusually cold weather. Gore visited Toronto three times during 2008, and Toronto ended up with its heaviest annual snowfall since 1883. This "proves" nothing, of course, but it is genuinely snort-worthy.

Every single doom and gloom environmental prediction for 2008 (melting polar ice caps, rising sea levels, numerous catastrophic hurricanes and typhoons) utterly failed to materialize. In fact 2008 may prove to be the coolest year of the past decade. On the other hand, the sun has virtually ceased its normally robust sunspot activity. This has caused a number of scientists to postulate that fluctuations in the earth's climate and sunspot activity may be closely linked.
2008 was also the year that man-made climate change skeptics began to form strong organizations and issue strong statements, such as the Global Warming Petition Project, which has been signed by 31,000 individuals with university degrees in science including 9,000 PhD's. And The Heartland Institute is now forcefully fighting back against climate change hysteria. It features an impressive roster of contributors including Fred Singer, Steven Milloy, and Roy Spencer.

So where does all of this leave us? The case for man-made global warming/climate change has always rested on shaky ground. But in order to preserve their plans for massive fossil fuel taxes and the expensive dismantling of our current energy infrastructure, environmental extremists have turned climate change into a religion, proclaiming that "debate is over," branding anyone who disagrees with them a "denier" (thus invoking Holocaust imagery) and declaring that time is running out and that we must do something now! When that fails to work, there's always the modern academic Inquisition -- ask Bjorn Lomborg for details. And if public inquisition and castigation fails, there is an ultimate solution: threatening uncooperative scientists with the loss of university tenure and precious government research contracts.

Over at his Urgent Agenda blog, William Katz recently referenced President Eisenhower's 1961 Farewell Speech. Liberals love this speech, because it contained explicit warnings about the "military-industrial complex," which has become one of the great catch-phrases of modern anti-war dogma.

But Eisenhower, a far more brilliant man than he has been given credit for by the Left, also had this to say:
Akin to, and largely responsible for the sweeping changes in our industrial-military posture, has been the technological revolution during recent decades. In this revolution, research has become central; it also becomes more formalized, complex, and costly. A steadily increasing share is conducted for, by, or at the direction of, the Federal government ... Partly because of the huge costs involved, a government contract becomes virtually a substitute for intellectual curiosity. For every old blackboard there are now hundreds of new electronic computers. The prospect of domination of the nation's scholars by Federal employment, project allocations, and the power of money is ever present and is gravely to be regarded. Yet, in holding scientific research and discovery in respect, as we should, we must also be alert to the equal and opposite danger that public policy could itself become the captive of a scientific technological elite.

With the Democrats and their prophet of doom James Hansen at the helm of our government, bolstered by the anti-capitalist sentiments deeply rooted within our press, I fear that we are headed directly toward that ultimate solution. But our understanding of the Earth's climate is still far too primitive for anyone to declare that climate debates are "over." Now is the time for us to resist political and financial threats and demand to keep the climate debate open and vigorous. After all, we have 2008 on our side. How much does the other side have left?