Man Based Global Warming....

[JSH]

Originally Posted by TimBikes

How is it that all the cooling is "natural" and all the "warming" man-made? Is there no "natural" warming?

Sure there is "natural" warming. I was giving the AGW argument for the recent plateau and current decrease in temperatures in spit of increasing CO2 concentrations.

[malorn]

How can a constant climate be used in all of these models when figuring mans impact on climate? Before man-made carbon has the planet's climate ever been constant?

[TimBikes]

Originally Posted by JSH

Sure there is "natural" warming. I was giving the AGW argument for the recent plateau and current decrease in temperatures in spit of increasing CO2 concentrations.

Got it.

[Alric]

Originally Posted by JSH

Sure there is "natural" warming. I was giving the AGW argument for the recent plateau and current decrease in temperatures in spit of increasing CO2 concentrations.

You realize there is no plateau. No cooling. Just because you guys repeat it doesn't make it so. I thought I had already corrected Tim on that point:



This contrarian idea came from a misinterpretation of the hadcrut3 data.

Remember now?

[Alric]

Also just wanted to point out the following NPR article based on a new study:

Study Busts Antarctica's Chill On Global Warming

Study Busts Antarctica's Chill On Global Warming : NPR

Antarctica was seemingly the only continent on Earth that had not been warming up, as far as scientists could tell. But now a new study finds that large parts of the southern continent have in fact been getting warmer.

So what about antarctica now?

[TimBikes]

Originally Posted by Alric

Also just wanted to point out the following NPR article based on a new study:

Study Busts Antarctica's Chill On Global Warming

Study Busts Antarctica's Chill On Global Warming : NPR

Antarctica was seemingly the only continent on Earth that had not been warming up, as far as scientists could tell. But now a new study finds that large parts of the southern continent have in fact been getting warmer.

So what about antarctica now?

Alric - as I already point out to Scott, this NPR soundbite ignores the fact that - as seen in the original journal article:

• Most of the Antarctic warming occurred prior to 1980
• Since the late 1990s, the region has been cooling

So what about Antarctica now? Well, it appears not to have responded dramatically to CO2 and in the past 10 years temperatures there have declined, in contradiction with increases in CO2 and global warming predictions.

[TimBikes]

Originally Posted by Alric

You realize there is no plateau. No cooling. Just because you guys repeat it doesn't make it so. I thought I had already corrected Tim on that point:

This contrarian idea came from a misinterpretation of the hadcrut3 data.

Remember now?

Alric - the emperor has no clothes.

How is it you can't see the lack of warming that everybody else can?

See the yellow highlights -- from 2001 - 2007 there is no upward temperature trend in any of the charts. And if you add 2008, you won't see it either.

[Alric]

Originally Posted by TimBikes

Alric - as I already point out to Scott, this NPR soundbite ignores the fact that - as seen in the original journal article:

• Most of the Antarctic warming occurred prior to 1980
• Since the late 1990s, the region has been cooling

So what about Antarctica now? Well, it appears not to have responded dramatically to CO2 and in the past 10 years temperatures there have declined, in contradiction with increases in CO2 and global warming predictions.

That's precisely the notion the newer study contradicts. The parts of antarctica that are being measured have warmed along with the world average.

"Steig and his colleagues have done just that for Antarctica, taking the sparse temperature records of the past 50 years and combining them with satellite records that cover a much greater area, but don't go back so far in time. Combining those records, they now report that a big chunk of Antarctica — the western part of the continent — has in fact been warming up, like the rest of the world.

Temperatures have risen by about 1 degree near the equator to more than 5 degrees near the North Pole."

Which is exactly what the author of the original antarctic warming said could happen.

Regarding your graph. Would you also have said the same for the three previous and longer plateaus? There is no cooling. The trend overall continues upward.

[MegansPrius]

Originally Posted by TimBikes

Alric - as I already point out to Scott, this NPR soundbite ignores the fact that - as seen in the original journal article:

• Most of the Antarctic warming occurred prior to 1980
• Since the late 1990s, the region has been cooling

So what about Antarctica now? Well, it appears not to have responded dramatically to CO2 and in the past 10 years temperatures there have declined, in contradiction with increases in CO2 and global warming predictions.

The cooling in east Antarctica is likely due to ozone erosion, and likely to reverse. The NY Times has a good write up of the study today, and mentions a forthcoming paper in AGU which independently confirms these results.

As with earlier studies, the scientists found that more recently, since the late 1970s, temperatures had actually cooled in East Antarctica, a phenomenon that many atmospheric scientists attribute to emissions of chlorofluorocarbons, a family of chemicals used as coolants that destroyed high-altitude ozone. Because those chemicals have since been phased out, the ozone hole is expected to heal, and the cooling trend may reverse.

“Obviously the situation is complex, resulting from a combination of man-made factors and natural variability,” said Michael Oppenheimer, a professor of geosciences at Princeton, who was not involved in the research. “But the idea of a long-term cooling is pretty clearly debunked.”

Dr. Monaghan, who had not detected the rapid warming of West Antarctica in an earlier study, said the new study had “spurred me to take another look at ours — I’ve since gone back and included additional records.”

That reanalysis, which used somewhat different techniques and assumptions, has not yet been published, but he presented his revised findings last month at a meeting of the American Geophysical Union.

“The results I get are very similar to his,” Dr. Monaghan said.

[TimBikes]

Originally Posted by MegansPrius

The cooling in east Antarctica is likely due to ozone erosion...

You trumpeted the study as showing the east Antarctic was warming, but when challenged now say it is cooling. Which is it?

If you have access to the original journal article, please provide an image of "Figure 2" so we can all look at the data and judge for ourselves.

I also find it mildly amusing that you (RealClimate) have to reach back 50 years (instead of 30) in order to produce a rising temperature trend:

"Our results do not contradict earlier studies suggesting that some regions of Antarctica have cooled. Why? Because those studies were based on shorter records (20-30 years, not 50 years) ..."

This suggests that any increases in temperature in east Antarctic are not recent.