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Tuesday, October 04, 2005

Lab report grade: D

I really don't like doing this... OK I do because it is fun and I love science. Buuutttt, the science reporter is at it again. Still banging on cluelessly about "global warning", here stitching up an apparent case with contradictory reports and unscientific press releases. This time he has a correspondent who is a "global warming sceptic" (insert your definition of that here: there is no warming? there is warming but not human induced? It does make more than a slight difference really) who points to evidence rather than making assertions. All well and good, but then pointing to evidence is not much good if you misrepresent it, eh Einstein?

As is often the case with Dr Brown's attempts at analysis it is easier to go backwards. First
The BAS researchers also conducted work this year that they believe "points the finger squarely at CO2 rather than the ocean currents" as the trigger for past atmospheric warming incidents. In short: the news on Antarctica is not good either.
What does the press release talk about? A study concluded that the climate 3 million years ago became warmer more likely because of CO2 concentrations rather than ocean currents. All fine and well, for those two causal factors. But clearly it doesn't say anything about other possible plausible causes, just that a change 3 million years ago was more likely dominated by possible CO2 increases than ocean currents, given the indirect method of measuring both. Not that the information is not valuable as another possible piece in the puzzle, it is however no smoking gun. I'll just note this from the release
If the warming was caused by ocean currents, we would expect to see cooling at the tropics and warming at the poles. Conversely, if CO2 was the cause then we would expect both the tropics and the poles to warm.
Russell began with this, from his correspondent
Responding to the recent stories about Arctic melting, he cites this 1990 paper and this 2002 Telegraph story, which both note evidence that while the Arctic might be melting, the Antarctic is mostly cooling.
Which on the face of it supports the ocean current effect dominating CO2 effects. Here is some of the Telegraph article, taken from Nature
Previous claims that the Antarctic is warming may have been skewed because the measurements were taken largely on the Antarctic Peninsula, which extends toward South America and which is warming five times more quickly than the rest of the world.

"Although some do predict areas of cooling, widespread cooling is a bit of a conundrum that the models need to start to account for," he said.

A drop in Antarctic temperatures is a puzzle because most climate models suggest that polar regions should respond first and most rapidly to worldwide temperature changes.
Again it would appear that a peninsula getting warmer while the rest of a continent cools would seem to be more of an ocean current thing. But the reference to the 1990 article (abstract only) do not support Russell's assertions, because
The best guess that can be made is that Antarctic air temperatures now appear to be warmer, by at least 1°C, than those prevailing during the first decade of the twentieth century. The result is broadly consistent with temperature changes that have been reported for both land and marine regions over the rest of the Southern Hemisphere. This result is, however, in contrast with the course of temperature change over the Arctic region, where temperatures are now only 0.35°C warmer than in 1901.
The Antarctic has warmed more than the Arctic? Granted the actual paper may have more detailed results but this available piece doesn't support what Russell wrote: "both note evidence that while the Arctic might be melting, the Antarctic is mostly cooling". Onto the final paragraph
But more recent work from the British Antarctic Survey, which conducts the most thorough ongoing research programme, is far from reassuring. BAS scientists concluded earlier this year that the Intergovernmental Panel on Climate Change may actually have lowballed estimates on the contribution of Antarctic melting to sea level rise.
Now this mostly talks about extra sea ice melting leading to increased glacial flow due to lack of resistance. However the crucial statement is not mentioned by Russell
It is not known whether the melting is the result of a natural event or the result of global warming.
Also not discussed is the snowfalls on the continent itself, since the sea ice itself can't raise sea levels then it depends critically on what is happening far inland and if the sea is warming then evaporation is also on the up. Lastly
Essentially, the East Antarctic Ice Sheet is thickening - as predicted by some models - as a result of climate change, but two other areas are thinning quite dramatically. "In the last 50 years," the BAS researchers say, "the Antarctic Peninsula has warmed faster than anywhere else on Earth."
The link is another press release, where we can read the guts of it as
Computer models suggest that the East Antarctic Ice Sheet may thicken as a result of climate change, but observations from satellites and aircraft show that two other areas are thinning. These conflicting effects and the challenge of measuring them make it difficult at present to predict the contribution of Antarctica to sea level rise, there is no doubt that its role will be significant.
One area is predicted to thicken by some models, readings from a different area show thinning. What do the models say for the thinning area and what are the actual results for the predicted thickening area? This is very dodgy territory and highly unscientific for drawing vague conclusions such as "there is no doubt that its role will be significant". Significant as in a lot or hardly anything? The fact that the Antarctic Peninsula has warmed faster than anywhere else on Earth is irrelevant. Somewhere had to warm fastest. There is stuff about ice sheets breaking up, but no mention of this is common or not. But that is the problem of reading press releases rather than the actual papers (if they exist) and anyone who has been involved in obtaining grant money knows the key role of directed focus and emphasis. Finally, if we accept the conclusions of the BAS press releases even then it appears that oceanic currents are more likely culprits than CO2 itself, if we restrict the discussion to just those two causes, which is in itself a gross exaggeration.
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Posted by Chefen | 10/04/2005 06:30:00 PM

3 Comments:

Blogger Whaleoil said...

It is hugely spurious to suggest that the so called "Global Warming" will melt Antartic ice. Most of this Ice is Land based and thus not likely to make it to water to be able to contribute to the bullshit theory of rising sea levels.

Also the average temperature of the Continental Antarctic in Summer is something like -30 degrees C. Thus in order for so called Global warming to have any major effect the Global temperature would have to rise by more than 30 degrees, highly unlikely.

Ice floating on water does not contribute in anyway to sea levels rising if it melts so it really only comes down to land based ice.

10/04/2005 08:09:00 PM  
Blogger Antarctic Lemur said...

Ahh but maybe some areas of ice off the continent itself are held up by their connections with the rest of the ice cap! (I'm not saying this is true, just looking for an explanation to create the desired catastrophe. Maybe it is true!).

10/04/2005 09:15:00 PM  
Blogger Whaleoil said...

Still needs to be a lot warmer than it is...Water freezes at 0 degrees and in the summer it only sometimes reaches 6 degrees a the very edges of the continent, like the sticking out bit that points at South America.

10/04/2005 10:09:00 PM  

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