Arctic ice faces accelerated meltdown

SpaceDaily ^ | 12/12/2006 | AFP

[cogitator]

The worrying shrinkage of Arctic sea ice could accelerate dramatically in coming decades, leaving the planet's most northerly ocean virtually devoid of ice in summer by 2040, according to a study published on Tuesday.

The paper, which appeared in the US journal Geophysical Research Letters, mainly points the finger at greenhouse-gas emissions.

It warned that if carbon pollution continues to increase at present rates, the Arctic's normal cycle of freezing and thawing faces catastrophic disruption.

A simulation run by scientists at the National Center for Atmospheric Research (NCAR) and Canada's McGill University predicted that the area covered by ice in September -- before new ice begins to form each year -- could shrink from about 5.9 million square kilometres to 1.9 million sq. kms. (2.3 million to 770,000 sq. miles) within a decade.

By 2040, "only a small amount of perennial sea ice" would remain along the north coasts of Greenland and Canada in summer, NCAR said in a press release.

In winter, ice thickness would be reduced from about 3.5 metres (about 12 feet) to less than a metre (three feet).

"We have already witnessed major losses in sea ice, but our research suggests that the decrease over the next few decades could be far more dramatic than anything that has happened so far," said NCAR scientist and lead author of the study, Marika Holland.

Greenhouse gases trap the Sun's heat, gradually forcing up Earth's surface temperature.

But several peripheral factors could also account for such a rapid meltdown.

Open water absorbs more sunlight than ice, accelerating the rate of warming and leading to more ice loss. In addition, global climate change is likely to drive warmer ocean currents into the Arctic region.

"This is a positive feedback loop with dramatic implications for the entire Arctic region," Holland said.

The shrinkage of the Arctic ice cap is viewed with alarm by scientists, as it appears to perturb important ocean currents elsewhere, notably the Gulf Stream, which gives western Europe its balmy climate.

It also threatens animals such as polar bears and seals that depend on ice -- as well as Inuits and other native peoples who hunt these animals and have to travel on thinner ice in this quest.

There are geopolitical implications, too, as Canada, Russia and the United States jockey to claim rights over transpolar passages that open up within their newly ice-free waters.

In September, European scientists unveiled satellite images from late August showing that perennial sea ice -- thick ice that is normally present year-round and is not affected by the Arctic summer -- had disappeared over an area bigger than the British Isles.

The study released Tuesday concludes that reduced rates of greenhouse gas emissions could slow the ice loss. "Our research indicates that society can still minimize the impacts on Artic ice," Holland said.

[_Jim]

Blackout strikes millions-8/2003 ... Though cause unclear, officials quickly dispel

Please; the cause for this is WELL DOCUMENTED at this point.

[_Jim]

Global warming is a fact

Please cite source; please do not use those stations' data which is highly uestionable due to the factors I cited earlier.

[Buckhead]

Well, I read some of your links. Here is the rejoinder of the first link to the repeated 1,000 year gap between increasing temperatures and increases in CO2:

All that the lag shows is that CO2 did not cause the first 800 years of warming, out of the 5000 year trend. The other 4200 years of warming could in fact have been caused by CO2, as far as we can tell from this ice core data.

"Could … have been caused … for all we can tell ..."

In the last link, which you characterize as a countering a common skeptical argument, the skeptics are winning decisively. Post after post blowing gaping holes by proving that CO2 increases repeatedly trail temperature increases, and that there are multiple, sustained high levels of CO2 during extended cooling periods. They are saying there is little to no evidence in the Vostok record to support the claim that CO2 is a cause of global warming, and that the claim is being abandoned.

So the dude holding the fort says well, maybe the data are wrong, and that it doesn't really matter if the models can't definitively explain the past. Because the theory is an important element of policy change.

But, he got his hat handed to him on that. 1. Nobody is asking for definitive. Bearing a remote resemblance to the data would be a start. 2. If the model can't remotely accommodate the historical data, then it's not even a theory. It's just a conjecture that's been refuted by the data.

The claim that CO2 is a cause of global warming is in tatters.

[LeGrande]

...near-virtual certainty of a 1.5 C rise by 2100

So if my memory doesn't fail me again, the average temp has increased about .6 C in that last hundred years. 1998 was the hottest year and the temps have decreased since then by almost .1 C. CO2 concentrations have been steadily increasing since 1998 and yet the temperature declines?

So with a 100 years of reasonably good data and a temperature increase of .6 C, 'scientists are now predicting a 1.5 C increase in the next 100 years? Are they basing this on a predicted tripling of the CO2 in the atmosphere (already at a multimillion year high)? Is there a saturation point at which increases in CO2 no longer have any effect, ie. the wavelengths are completely blocked?

Is water a green house gas? And lastly what is the most accurate computer model and are the algorithms and data available?

[staytrue]

Bottom line: Satellite data indicates global warming.

And, warm weather species are gradually moving northward.

[Parmy]

Good! Maybe we can grow corn on Greenland, again.

[no dems]

Hey, if Alaska melts, Texas will be the largest state again.

[_Jim]

Bottom line: Satellite data indicates global warming.

A simple assertion lacking a cite or anything else to 'back it up'; you call that evidence?

Algore has said as much ...

(You have probably also overlooked the fact that there is some disagreement to the interpretation of said 'Satellite data'. If you press this angle I will be bringing out this aspect JUST as there is disagreement and debate on the accuracy of the surface temperature record.)

[staytrue]

You have probably also overlooked the fact that there is some disagreement to the interpretation of said 'Satellite data'. If you press this angle

You've just admitted that you know the satellite data is showing global warming.

You are an ostrich head in the sand moron.

[ancient_geezer]

Bottom line: Satellite data indicates global warming.

Weather changes constantly, both up and down.

 

Globally Averaged Atmospheric Temperatures
(NASA)

This chart shows the monthly temperature changes for the lower troposphere - Earth's atmosphere from the surface to 8 km, or 5 miles up. The temperature in this region is more strongly influenced by oceanic activity, particularly the "El Niño" and "La Niña" phenomena, which originate as changes in oceanic and atmospheric circulations in the tropical Pacific Ocean. The overall trend in the tropospheric data is now +0.08 deg. C/decade (through 2004). Click on the charts to get the numerical data.

Surface thermometer measurements indicate that the temperature of the Earth is warming at an average rate close to +0.20 deg. C/decade since 1979, while the satellite data shows a warming trend of about half of this. These differences are the basis for discussions over whether our knowledge of how the atmosphere works might be in error, since the warming aloft in the troposphere should be at least as strong as that observed at the surface. A scientific report on what this apparent discrepency between the satellite and surface data means in the context of global warming theory will be completed in 2005 as part of the U.S. Climate Change Science Program.

 

 

 

Global Warming is more a matter of one's chosen time frame among natural causes of variation:

 

Ice Ages & Astronomical Causes
Brief Introduction to the History of Climate
by Richard A. Muller

Origin of the 100 kyr Glacial Cycle

 

Figure 1-1 Global warming (NOAA land and ocean temperatures)

 

Figure 1-2 Climate of the last 2400 years (GISP2)

 

 
Figure 1-3 Climate of the last 12,000 years (GISP2)

 

 

Figure 1-4 Climate of the last 100,000 years (GISP2)

 

 

Figure 1-5 Climate for the last 420 kyr, from Vostok ice

[Always Right]

Actually, clouds are the most effective of the greenhouse gases. If you want a warm winter night or a really mugged unbearable summer night, there is nothing like cloud cover to do the trick.

Clould also reflect light and prevent heat from reaching earth. At night time it serves retain heat, but not during the day. The long term effect should be a net cooling.

[cogitator]

Again you misquote him. Just what the hell is wrong with quoting somebody accurately?

Verbatim quote: "For these reasons I would like to discuss an important body of scientific research that refutes the anthropogenic theory of catastrophic global warming. I believe this research offers compelling proof that human activities have little impact on climate."

and of course " I called the threat of catastrophic global warming the "greatest hoax ever perpetrated on the American people," a statement that, to put it mildly, was not viewed kindly by environmental extremists and their elitist organizations."

Warmed Over American Prospect: Sen. James Inhofe's Science Abuse

"In his latest speech, timed to coincide with the final steps toward implementation of the Kyoto Protocol (which the United States won't be joining), Inhofe asserted that "put simply, man-induced global warming is an article of religious faith."

Please clearly note the absence the modifier "catastrophic" in the above quote. It would normally appear in front of "global warming", had Inhofe remembered how he's been phrasing it elsewhere.

Happy now?

[cogitator]

The overall trend (from UAH only) is now +0.13 C through 2006. Nice updated chart, though.

[cogitator]

You have probably also overlooked the fact that there is some disagreement to the interpretation of said 'Satellite data'. If you press this angle I will be bringing out this aspect JUST as there is disagreement and debate on the accuracy of the surface temperature record.

Oh please do! Don't forget to highlight the alternate analyses of the MSU satellite data by the RSS group and by Vinnikov & Grody.

I'll even help!

Description of MSU and AMSU Data Products

Global Warming Trend of Mean Tropospheric Temperature Observed by Satellites

[ancient_geezer]

The overall trend (from UAH only) is now +0.13 C through 2006. Nice updated chart, though.

I woudn't get too excited over the last two years of data if I were you. Which is why NASA posts trend statistics only for the older (pre-2005) data set.

There is a bit of a problem with 2005 & 2006 data, as the both satellites (NOAA 15 & NOAA16) have unresolved calibration drifts inducing divergence in their temperature data as well as substantial drift from nominal. They are using only information one satellite(NOAA-15) at present. Its deviation however, is indeterminate as NOAA-15 has been showing a substantial drift toward erroneous warmer temperatures.

see for current status of the data. http://www.nsstc.uah.edu/data/msu/t2lt/readme.05Dec2006

Update 5 Dec 2006 ******************************* Data products are still 5.2 and 5.1. For LT 5.2 and MT 5.1 we have eliminated the data from NOAA-16 after September 2005 when NOAA-16 began to diverge in a manner that suggested NOAA-16 was having problems. Thus, the data since Oct 2005 is based on NOAA-15. The net effect on this change was to increase post-Oct 2005 temperatures slightly, and thus the global trend is increased by about 0.01 C/decade.

Update 10 Nov 2006 ******************************* Notice that data products are back to version 5.2 for LT and 5.1 for MT and LS. We had hoped to solve the inconsistencies between NOAA-15 and NOAA-16 by this time, but we are still working on the problem. The temperature data for LT and MT are diverging, and we had originally thought that the main error lay with NOAA-15. However, after looking closely, there is evidence that both satellites have calibration drifts. We will assume, therefore, that the best guess is simply the average of the two. This is what is represented in LT 5.2, MT 5.1 and LS 5.1. These datasets have had error statistics already published, so we shall stick with these datasets for a few more months until we get to the bottom of the calibration drifts in the AMSUs. However, the error statistics only cover ther period 1978 - 2004. The last two years cover the period where the two AMSUs are drifting apart, so caution is urged on the most recent data.

Update 6 Oct 2006 ****************************** Another month and the same story, we are still finalizing the production of version 6.0. The values which will be placed on the website contain the earlier v5.2 data through Dec 2004 with the preliminary values from v6.0 from Jan 2005 to the present (Sep 2006). The largest changes occur in the last two years as NOAA-15 was drifting into warmer temperatures and its target temperature effect became evident. Again, this is a preliminary dataset designed only to give an idea of what is going on at the moment. We will update the daily files when the full v6.0 is ready. The monthly gridded files and the uahncdc files also reflect the use of the newer data in 2005 and 2006 only.

[cogitator]

Even though the data is useful, the inter-satellite calibration problems (which have dogged them before) show why this data set has to be utilized with awareness of its limits.

[ancient_geezer]

Even though the data is useful, the inter-satellite calibration problems (which have dogged them before) show why this data set has to be utilized with awareness of its limits.

Indeed. However, the variation as opposed to absolute value is of interest especially considering that we are currently peaking out in solar activity with projections looking towards a significant drop in the next decade. The consequent effects of modulating the heliopause on earth's low level cloud cover should become very apparent as we move forward from here.

Interestingly, perusing the NASA chart, the last few years of tropospheric temperatures appear to be peaking out in the satellite data as well.

The next 10-20yrs of empirical temperature data coupled with solar activity ought to be interesting indeed.

 

 

The interesting test will be on whether or not ocean and tropospheric temperatures drop as this 8000 year high in solar activity reverses as it is predicted for coming decades.

 

NASA - Long Range Solar Forecast

[ExSoldier]

Amazing how the various "authorities" keep shifting conditions and projected timelines to reflect changes in data that aren't in keeping with their paradigm. It's like the myth of PEAK OIL or that Oil is dead dinosaurs. Those guys (many of the same folks who're not ranting about the imminent danger of global warming) predicted in the 1960's, 70's, 80's and 90's that world supplies of oil would be nearly 100% depleted within 25 years. 25 years...at each new era.

I've just gotta ask myself exactly what other agenda is at work here? Then I look at the political activists and other behind the scenes figures at work...HARD at work....pushing this "imminent catastrophe" on an ignorant and trusting populace. Pushing hard and fast so as to enact global change before a gently slumbering populace awakens.

Check THIS out: U.N.

[Tolerance Sucks Rocks]

No, they're not. While there are a few skeptical holdouts, the vast majority acknowledge the reality of anthropogenic climate change.

Last I heard, there were several thousand skeptics. However, I don't think all of them were climate scientists.

[ExSoldier]

(many of the same folks who're not ranting about the imminent danger of global warming)

not = "NOW." Amazing the difference of one little word. Now the sentence makes more sense!

The same folks ranting about global warming are also ranting about peak oil and the world running out of fuel.....geeeze, you'd think one global catastrophe is enough...but nooooo they KNOW that to spur immediate, global change in entire societies and cultures, there has to be a major "threat."

When the USSR died and the threat of imminent thermonuclear war went away....then the primary motivator also left. Those agitators had no place to go to advance the agenda. So they saw an opening in radical environmentalism. BINGO! Hey this is better than doomsday by bomb. It's doomsday alright but we can all prevent it....our "enemies" and we can put aside old wounds and differences and come together as human beings for the sake of planetary survival ~bile rising in throat, fighting the urge to REgurge~ and presenting a united front save the world.

All it takes is for a little bit of change in how we live and (oddly enough) how we govern ourselves. There's no hope left. No more oil and even if there were, all this industry and those evil SUVs are smothering our beloved mother Earth!