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Global warming may not be the culprit after all when it comes to Artic changes

Climate data can be difficult to analyze. Take for instance global temperature changes. Whereas the Northern Hemisphere has been warming, the Southern half of the planet is cooling. While Antarctic Ice is at near-record levels, the Northern Pole is warming at an unprecedented pace-- much faster than global warming models predict.

A new study published in the journal Nature identified a possible cause for this discrepancy. It identifies a natural, cyclical flow of atmospheric energy around the Arctic Circle. A team of researchers, led by Rune Graversen of Stockholm University, conclude this energy flow may be responsible for the majority of recent Arctic warming.

The study specifically rules out global warming or albedo changes from snow and ice loss as the cause, due to the "vertical structure" of the warming ... the observed warming has been much too weak near the ground, and too high in the stratosphere and upper troposphere.

This study follows hot on the heels of research by NASA, which identified "unusual winds" for rapid Arctic ice retreat. The wind patterns, set up by atmospheric conditions from the Arctic Oscillation, began rapidly pushing ice into the Transpolar Drift Stream, a current which quickly sped the ice into warmer waters.

A second NASA team, using data from the the GRACE (Gravity Recovery and Climate Experiment) satellite, recently concluded that changes in the Arctic Oscillation were "mostly decadal in nature", rather than driven by global warming.



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By Andy35W on 1/7/2008 2:19:51 AM , Rating: 2
Looking at their preliminary figures, which does not include December, they give the difference from the average global temperature as:-

2006 +0.42C
2007 (Jan-Nov) +0.41C

So it was not hotter than 2006, but only just. Your examples try to give an impression that the earth swung to "cold", however your examples are all local and if you take the global picture then 2007 seems like it will be the 7th warmest on record.

As for the suggestion that "much" of the southern hemisphere saw some of the coldest weather ever recorded this does not tally with it being the 9th warmest year for the southern hemisphere. This was behind the northern hemisphere where it was the 2nd warmest I admit.

As it is predicting the future though and with the complexity of weather it will be interesting to see how their "cooler" forecast for 2008 stands up.


By masher2 (blog) on 1/7/2008 10:59:48 AM , Rating: 2
> "So it was not hotter than 2006"

2007 was 0.01 cooler than 2006 yes. But it was 0.065 cooler than 2005 and a full 0.1 degrees cooler than 1998.

The trend is even more pronounced for the SH:

2003 0.280
2004 0.277
2005 0.266
2006 0.250
2007 0.234

The past five years have wiped out 20% of all warming seen since 1940.


By modelmania on 1/7/2008 11:30:05 AM , Rating: 2
Saying "7th warmest on record" makes it sound, to the uninitiated, very dramatic.

Given that:

1. The record is very short.
2. The record started right at the coldest point in the past 600 years or so.
3. It has been cooling since 1998.

The "7th warmest on record" therefore just means we have reached a local maximum (not a particularly remarkable one on any time scale) and the temperature is headed down again.

No biggie...


By Andy35W on 1/7/2008 5:17:20 PM , Rating: 2
>Saying "7th warmest on record" makes it sound, to the uninitiated, very dramatic.

How does "the top 11 warmest years all occur in the last 13 years" sound then to the initiated like yourself?

It's interesting to note that when I simply state it's the 7th warmest on record I am accused of dramatisation but when the point I am stating against contains such sentences as

"Buenos Aires saw its first snow in 89 years"
"Peru had to declare a state of emergency after hundreds of people died from the cold"
"New Zealand and Chile lost hundreds of millions from frozen crops"

I think I can get away with it to be honest.


By rninneman on 1/7/2008 9:03:03 PM , Rating: 2
Irony is, most ecochondriacs are still trumpeting 1998 as the warmest year on record, when 1934 actually is the warmest year on record.

http://www.dailytech.com/article.aspx?newsid=8383

Your "top 11 warmest years all in the last 13 years" is false. Only 3 of the warmest years on record were in the last 13. 5 of the top ten were before WWII!

Why would they not want to acknowledge this though? Probably because it only further diminishes the possibility of AGW.


By Andy35W on 1/8/2008 11:56:20 AM , Rating: 2
Warmest year globally? Do you have a figure for that? I am taking details from the Internet so mine could be wrong, but as this is about Met Office in general and their predictions I can really only use one source.

Looking at

http://www.metoffice.gov.uk/corporate/pressoffice/...

I can't see 1934 at all on that graph.

One thing I do not like about that graph is the colours it picks, for the 1990's onwards it picks a hot colour, for earlier years it picks a cold colour .. talk about subjective impressionism ! tut tut. They should all be in black and the only thing that matters is the distance up the Y axis.


By rninneman on 1/10/2008 3:38:19 PM , Rating: 2
http://www.norcalblogs.com/watts/2007/08/1998_no_l...

That is the NASA study I was referring to which happens to be the darling of the IPCC. The original data from NASA also confirmed 1998 was the warmest on record, but someone analyzing the data realized the data had been analyzed by code that was not Y2k compliant. How pathetic is that?

Good point about the colors chosen on your link.


By modelmania on 1/8/2008 10:14:36 AM , Rating: 2
quote:
How does "the top 11 warmest years all occur in the last 13 years" sound then to the initiated like yourself?


The statement is a relatively meaning-free, dramatization. Since everyone agrees that there has been a period of global warming since the Little Ice Age in the late 1800s (with ups and downs), it follows obviously (and is a virtually equivalent statement, in fact) to say that the most recent years have been the warmest!

But, of course, whether or not there has been some warming in the past 100+ years is NOT at issue. The real issue is whether man has had any impact on that trend.

Another VALID issue is whether that warming trend has actually stopped, which, based on the data for the last 10 years, appears to be the case with the numbers flat or trending down slightly.

Continually, repeating that the most recent years are the "warmest" without qualifying the statement by adding "in the last couple of hundred years" is disingenuous. We all know that a couple of hundred years is an irrelevantly small time period in climate history, and we all know that there have been warmer periods in the earth's recent history (within 600 years), and we all know that the rate of change of the temperature is within the range of temperature change rates throughout known and studied global climate history (before any potential man-made influences).

On the contrary, to site anecdotal examples like Buenos Aires, Peru etc to illustrate the larger point that the temperature in the Southern Hemisphere is cooling at the moment was stated completely in context and doesn't exaggerate or fail to mention any crucial facts. Those are simply factual illustrative anecdotes. They don't prove the fact that the Southern Hemisphere is cooling, the temperature measurements themselves prove that. The examples help to illustrate. They are used totally in context, and that discussion was not framed in a disingenuous way leaving out critical details.

Your statements such as "7th warmest on record" and "11 warmest years all occur in the last 13" are context-free alarmism that when put into context are shown to be nothing of significance.


By Andy35W on 1/8/2008 12:28:10 PM , Rating: 2
As per my last graph

http://www.metoffice.gov.uk/corporate/pressoffice/...

I don't see many downs since the last Little Ice age in the late 1800's. In fact none at all, but again it may be wrong, so please provide contrary evidence.

You make some good points about whether it is man made or not for the last 100 or so years but you cannot say " we all know ..." repeatedly as if it is obvious, you have to show it by some facts and figures or a graph. We don't all know.We are willing to be educated though or see more data to chew over.

And when did localised anecdotal evidence ever illustrate anything about a global statistical process over a long period of time? That's like me claiming global warming because of hurricane Katrina. That sort of thing IS nothing of significance. Trends will always be more relevant.

Finally, Peru was a very bad example to choose. It is just south of the equator but it's highest mountain is at 21000 feet as it lies along the Andes mountain chain. So is that snapshot illustrative of the "cooling" of whole of the southern hemisphere for 2007? No. It shows nothing at all.


By modelmania on 1/8/2008 2:17:08 PM , Rating: 2
quote:
I don't see many downs since the last Little Ice age in the late 1800's. In fact none at all, but again it may be wrong, so please provide contrary evidence.


Here is a recent graph from the National Climatic Data Center:

http://www.ncdc.noaa.gov/img/climate/research/2005...

It shows in broad strokes:

1. Temperature dropping from 1880 to 1893 (.1deg)
2. Going up from 1893 to 1897 (.1deg)
3. Going down from 1897 to 1908 (.2deg)
4. Going up from 1908 to 1942 (.4deg)
5. Going down from 1942 to 1950 (.1deg)
6. Staying the same from 1950 to 1975
7. Going up from 1975 to 1998 (.6deg)
8. Staying the same since 1998

Many ups and downs in the past 130 years.

quote:
You make some good points about whether it is man made or not for the last 100 or so years but you cannot say " we all know ..." repeatedly as if it is obvious


Sorry for assuming that we all know. But I assumed that everyone in this discussion is aware of the Medieval Warm Period. There is an excellent graph I found in a presentation by Robert Carter graphing oxygen isotope data for the last 5000 years. The data is from the GISP2 Greenland ice core. Look at Page 9 of this 14 page PDF file.

http://icecap.us/images/uploads/200705-03AusIMMcor...

The caption reads:
quote:
FIG 10 - Oxygen isotope time series for the last 5000 years, GISP2 Greenland ice core (light line; same dataset as Figure 7), fitted with a
moving average (dark line; after a slide by Andre Illarianov, 2004). The Late 20th Century Warm Period represents the latest of a regular
millennial cycle of similar warm periods (grey stripes). The Late 20th Century Warm Period may have equalled the magnitude of the
Mediaeval Warm Period, but it has not yet attained the warmth of either of the preceding Roman or Minoan Warm Periods.


On that same page, Fig 11 shows the rate of temperature changes (per 100-year interval) over the last 48000 years based on oxygen isotope ratios from the same GISP2 data. It clearly shows much greater rates of change than the most recent 100 years in many (if not most) of the centuries in the last 48000 years. Here is the caption of that graph:
quote:
FIG 11 - Rate of temperature change for the last 48 000 years, in °C/century, based on the analysis of oxygen isotope ratios from the
GISP2 ice core (same dataset as Figure 7; after a slide by Andre Illarianov, 2004). Note that during the last 9000 years of the Holocene,
temperature change occurred regularly at rates between +2.5° and -2.5°C/century. Earlier, during the last glaciation, rates of change
as high as 15°C/century are indicated.


You said:
quote:
And when did localised anecdotal evidence ever illustrate anything about a global statistical process over a long period of time?


I chose the word "illustrate" as opposed to "support" or "corroborate" or "demonstrate". Illustrate does not mean that it supports the conclusion. As I stated the conclusion of cooling temperatures in the Southern Hemisphere is supported by temperature measurement data.

The examples used were illustrative not supportive.


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