Mr Bolt's Myth #2: "It's Just a Falsehood."

This is a continuation of my analysis of Andrew Bolt's argument on "10 Global Warming Myths" (courtesy of Robb Smith's post). Thus far, Mr Bolt has refuted his own arguments, according to his sources.  I will go through each "Myth" and analyze them separately.  The following is Mr Bolt's "Myth #2":

THE POLAR CAPS ARE MELTING

Wrong.

The British Antarctic Survey, working with NASA, last week confirmed ice around Antarctica has grown 100,000 sq km each decade for the past 30 years.

Long-term monitoring by the US National Oceanic and Atmospheric Administration reports the same: southern hemisphere ice has been expanding for decades.

As for the Arctic, wrong again. The Arctic ice cap shrank badly two summers ago after years of steady decline, but has since largely recovered. Satellite data from NASA’s Marshall Space Flight Centre this week shows the Arctic hasn’t had this much April ice for at least seven years.

Norway’s Nansen Environmental and Remote Sensing Centre says the ice is now within the standard deviation range for 1979 to 2007.

Mr Bolt's sources:

1.  The British Antarctic Survey and NASA
2.  US National Oceanc and Atmospheric Administration
3.  Satellite data from NASA's Marshall Space Flight Center
4.  Nansen Environmental and Remote Sensing Center

Fact-check!  Very necessary!  (And I hope that this post will demonstrate the need for those at IL to keep a critical eye on the press and not just take the word of an opinion piece).

Note: the links got messed up while using Myspace blog as an editor; so I will have to go back and correct all of these links.  This will be a laborious process but I will post a note whenever I have done so.  I apologize for this inconvenience.  You can still do a search and look up these sources, as I've had to do with Mr Bolt, who did not even bother to offer any hyperlinks to sources because he assumed that his readers would take his word for it.

Argument 1: "Polar caps are melting" is a myth because The British Antarctic Survey, working with NASA, last week confirmed ice around Antarctica has grown 100,000 sq km each decade for the past 30 years.

Here is his source:

http://www.antarctica.ac.uk/press/press_releases/press_release.php?id=838

Falsehood.  The press release from 21 April 2009 by The British Antarctic Survey (BAS) and NASA states that while the sea ice extent around East Antarctica has steadily increased by 100,000 square km per decade for the past 30 years, the most dramatic changes are occurring in Western Antarctica, where large ice shelves in the Antarctic Peninsula are collapsing and disintegrating with greater frequency due to global warming.  The net effect is 0% increase/decrease in growth or loss for Antarctica. The concluding statement from the press release: "So the consensus view is that the Antarctic continent is essentially in balance at the moment and not losing or gaining ice overall." 

This balancing act between melting and cooling will not last, according to BAS and NASA scientists.  However, at the moment, an equilibrium exists between melting and disintegration of ice in West Antarctica and cooling, ice thickening, and increased sea ice extent on or around East Antarctica.  This regional cooling and ice growth around East Antarctica was caused by an ozone hole which appeared 30 years ago, so neither proves nor disproves global warming nor the growth or melt of polar caps.

 

Beginning approximately 30 years ago, CFC pollution from human activity spread south and became sucked into a vortex over Antarctica where an ozone hole appeared, cooling East Antarctica and expanding sea ice off the coast of East Antarctica.  Meanwhile, continues the report, for at least the past 50 years or more--large chunks of ice shelves have been collapsing and melting from Western Antarctica due to anthropogenic warming.  The ozone hole sucks in fierce winds from the Southern Ocean through its swirling vortex into the continent disbursing and amplifying both warm air from global warming to the west and regional cooling from the ozone hole to the east.  The scientists report that while there is currently a precarious steady-state between warming and cooling between the two different sides of the continent, the ozone hole is expected to heal to pre-1980 levels by the year 2050 and recover fully by 2100.  However, even prior to 2050--the ozone hole will lose its capacity to provide an equilibrium between warming and cooling and is expected to give way to rapid warming as the ozone hole recovers.

 

Something to consider in addition to regional cooling from the ozone hole and amplification of both warming and cooling is increased precipitation from global warming from ice melt in Western Antarctica (discussed elsewhere).  This melting and precipitation in the west is likely to be fed into the vortex and deposited as falling snow and ice over East Antarctica, thus thickening the eastern mainland ice and increasing sea ice extent along the coastal region.  However, it is very likely that East Antarctica may never melt away and slide into the sea because its bedrock exists above sea level.  This is not the case for Western Antarctica, where the bedrock lies several hundred to several thousand feet below sea level, leaving the western side vulnerable to melting. 

 

Given these conditions and factors, it is not surprising that scientists pay closer attention to the melting western side and to collapsing ice shelves in the Antarctic Peninsula (in Western Antarctica) than to the cooling and extent of sea ice growth surrounding East Antarctica.  Unlike newly-formed sea ice, these ice shelves in the west are ancient formations that are several hundred meters thick and provide structural stability for the continent.  By contrast, the expansion of sea ice surrounding East Antarctica are thin layers of ice floating on top of water. 

 

The thickness of Antarctic sea ice ranges anywhere from up to 1 meter to several meters thick.  Due to this relative thinness, Antarctic sea ice is seasonal ice that melts every spring and summer and re-forms every fall and winter.  As such the "growth" in Antarctic sea ice is limited to "extent," e.g. horizontal surface expanse or distance, but not to vertical depth or thickness.  Thus Antarctic sea ice--unlike Arctic sea ice in the Northern hemisphere--is much newer and thinner seasonal ice and is present only when the sun is most distant and dimmest from the Earth, and melts when the sun gets any warmer or closer: therefore, Antarctic sea ice is unable to provide albedo protection (white surface reflection of sunlight and heat back into space when the sun is hottest) and as such does not play a role in temperature regulation.  Nor does melting sea ice add to sea level rise.  As such Antarctic sea ice is not significant, although melting Arctic sea ice is very signficant (not because adding to sea rise--but because of their temperature-regulating capacity during the spring and summer months--which Antarctic sea ice cannot do).

 

The current sea level rise is thought to be largely caused by glacial melt in Greenland, Antarctica, and in every other continent with the exception of Australia (where there are no glaciers) but predominantly from Greenland, where glacial melt is occurring the fastest.  Second to Greenland is Western Antarctica.  Neither sea ice melt nor the melting of ice shelves contribute to sea rise because they are floating in water, although ice shelves are several hundred meters thick so are submerged mostly below water rather than the sea ice which is floating on top of water..  However, when ice shelves break off from continents, their weight displaces water which results in a slight sea level rise when ice debris from glaciers comes streaming and sliding down with it.  This is why disintegration of these ice shelves are a concern to scientists, since their collapse destabilizes surrounding formations causing further collapses, and eliminates the natural barriers that prevent ice sheets and glacial runoffs from sliding into the ocean.  When this occurs, there can be significant sea level rise.

 

If the main mass of the Antarctic ice sheet were to melt away, this melting would add 63 meters to the sea level.  If, on the other hand, this melting polar ice can be contained to smaller regions of the continent--such as confined to only to the vulnerable ice shelves on the outer regions of the Antarctic Peninsula or only to only parts of Western Antarctica --sea level would only rise by up to 1-6 meters rather than 63 meters.  This is a big "if," so only hypothetical; since ice shelves from the Antarctic Peninsula and elsewhere provide structural stability to the continent to prevent other areas from cracking up and disintegrating like dominoes or playing cards.  In addition, these ice shelves prevent glacial run-offs and mainland ice sheets from streaming down and sliding off into the deep blue yonder because they block them.  However, if these ice shelves were to break off and disintegrate completely, the law of gravity and motion predicts that this collapse can potentially start a chain of events that lead to glacial run-offs sliding off into the sea and more ice shelves collapsing into the sea and a dominoe effect.  And that is what we are observing in the Antarctic Peninsula.  Thereby potentially resulting in an additional sea rise of up to 63 meters instead of 1-6 meters from these ice shelves and the few ice streams and debris behind it. 

 

Needless to say, humanity and most species would be wiped out by a 63 meter sea rise but this is not to suggest that humans could not survive a 1-6 meter sea level rise: a leading climatologist at the recent Copenhagen conference of scientists thinks we can survive it as a species, but only 1 billion humans will survive it.  He estimates that this will be the population of humans in 2100.  Most likely they would be the richest and the most powerful humans with access to prime real estate on mountaintops or very high altitudes.

 

But let's suppose that we could suspend the laws of physics to hypothesize what may happen when only the Antarctic Peninsula and a few pebbles behind it (which is bound to occur--the debris or ice streams following ice shelf collapse, that is-- but stop short of the whole mainland icesheet also collapsing by this chain-reaction). One study concluded that such a collapse would be worse than previously estimated because the loss of mass in Antarctica from collapsing ice shelves reduces the gravitational force of the continent to pull water back toward the point of collapse.  As a consequence, ice chunks and glacial melt would fall into the water and add to sea level rise elsewhere, since the sea rise would ripple across the oceans and be pulled to more distant bodies, such as North America and other continents in the Northern Hemisphere, by gravitational force.  Thus, while good for Penguins and for the Mr. Bolt of the Southern Hemisphere (where sea rise would occur the least)--bad for North America and other continents in the Northern Hemisphere, where the sea level rise is more likely to occur on the order of 6 meters rather than the previously-estimated 1 meter or less.  However, these are based on predictions from global climate model so is not based on real world data, nor on Mr. Bolt's sources.  So to return to the BAS/NASA study, the scientists conclude for now, "So the consensus view is that the Antarctic continent is essentially in balance at the moment and not losing or gaining ice overall." 

 

"But," these scientists continue (jumping back a few paragraphs): while true that "at the moment," a precarious steady-state exists between warming/melting on the western side of the continent and cooling/growing of ice on the eastern side, this will not last: by 2100, BAS and NASA predict that the ozone hole will have recovered fully but by then, "there is likely to be around one third less Antarctic sea ice."

 

So if "melting polar ice caps" is a "myth" (according to the scientists themselves, according to Mr. Bolt--who cited this particular study to disprove the myth of melting polar caps), how do the same scientists also conclude that by 2100, "there is likely to be around one third less Antarctic sea ice"? 

 

The press release didn't state specifically just how there is likely to be around one third less Antarctic sea ice by 2100 in that particular sentence.  So taken out of context (and ignoring all preceeding sentences or any others surrounding it referring to "warming" or "melt"--), we could still accept the scientific view that there is likely to be around one third less Antarctic sea ice while maintaining Mr Bolt's position that "polar ice caps melting" is a myth.  In fact, it is only scientific to do so because science does not accept myth, so we jettison the myth and keep the science.  After all, there are a number of plausible theories both natural and man-made that could account for this loss of polar ice by 2100 without resorting to myth: one such theory being a giant wandering wormhole tunnel as an example of a naturally-occurring kind.  This wormhole tunnel could wander into the solar system in the year 2100 to suck in about 1/3 of Antarctica: thereby giving Mr. Bolt a little "wiggle room" to argue that "polar ice caps melting" is a myth although I do admit it would be a "stretch" (<--"stretch": get it??!  When things get sucked into wormholes, they become elongated and stretched as they get sucked in, according to theoretical physics). 

 

 

But more likely than a freak natural accident such as a wandering wormhole tunnel as an alternative explanation to melting of polar caps, a more plausible theory would be perhaps a collision from a large asteroid into Antarctica.  The impact of such a collision would not melt the ice--but evaporate it into gaseous form instead.  That way, it avoids melting into liquid.  But even more plausible from a scientific standpoint is the development of a technology to meticulously and systematically deconstruct 1/3 of Antarctica and send it into space.  Basically, dig up 1/3 of Antarctic ice, a big chunk at a time, and boost the whole lot of it in orbit.  All xtillion tons of it.
 

But what about magic?  Mr. Bolt doesn't appear to have an issue with magic--just more down on "myth," based on his attack of it in his op-ed.  But with magic, it would be like, "poof"! and 1/3 of Antarctic ice would be gone in an instant without having to resort to myth.  Just like that.  And all without melting, getting sucked into wormholes, turning gaseous, or being dug up by expensive super-doohickeys and sent into orbit.  After all, none of those alternative theories are permanent solutions since they merely send ice elsewhere, turns them into gaseous form, or sucks them out and stretches them through a giant wandering wormhole tunnel only to potentially come back to haunt earthlings and melt on us at a later time.  But with magic it would be like presto! disappear, forever.  In an instant.  And I believe in magic.  Why??  Why because it is so quick. 
 

Argument 2.  "Polar caps are melting" is a myth because long-term monitoring by the US National Oceanic and Atmospheric Administration reports the same: southern hemisphere ice has been expanding for decades.

Mr. Bolt's Source:

http://www.noaanews.noaa.gov/stories2009/20090416_globalmarchstats.html

Arctic sea ice coverage was at its sixth lowest March extent since satellite records began in 1979, according to the National Snow and Ice Data Center [NSIDC]. Average ice extent during March was 5.85 million square miles (15.16 million sq. km), 3.7 percent below the 1979-2000 average. Arctic sea ice usually reaches its maximum extent in March, and retreats to its annual minimum extent during September. March Arctic sea ice extent has decreased at an average rate of 2.7 percent per decade since 1979.

Antarctic sea ice extent in March was at its fourth-greatest level of the 31-year observational record. Antarctic sea ice extent reached 15.8 percent above its 1979-2000 average. Since 1979, Antarctic sea ice extent for March has increased at an average rate of 4.7 percent per decade.

The US National Oceanic and Atmospheric Administration (NOAA) which Mr. Bolt cites as disproving melting polar caps offers a brief two-paragraph summary of NSIDC whose data I am using as a supplement to NOAA's scant data (which is based on NSIDC, anywayz) of both northern and southern hemispheric ice coverage with statistical data with nothing more, so I've posted it above.  This data appears to be an analysis of surface sea ice extent between the two poles showing declines in the northern hemispheric ice (Arctic ice, -2.7%) and expansions in the southern hemisphere (Antarctic ice, +4.7%) per decade.  

Mr Bolt may have arrived at the conclusion that "'polar caps are melting' is a myth" by taking the differences between Northern hemispheric ice decline and Southern hemispheric ice growth (-2.7% vs. +4.7%, respectively).  It is therefore possible to extrapolate what you will from this data to superficially conclude that globally, the polar ice caps are not melting, but growing at an average rate of +2% per decade (+4.7 - -2.7 = +2% global polar average).  Not to say that it is scientific to do so; but only that this is perhaps what Mr Bolt did, since he apparently thinks that polar caps are identical on both ends in terms of degree of thickness and significance such that all that matters is extent of surface space.  It is therefore falsehood.  
 

Changes in northern hemispheric ice have a much greater impact on climate than changes in southern hemispheric ice.  Arctic ice in the Northern Hemisphere is much thicker, much older, has greater thickness (e.g., depth), and historically persist throughout the year and throughout human history until recent decades.  Thus, decline in Arctic sea ice is a much greater concern to scientists than declines or increases in seasonal and very thin surface Antarctic sea ice.  Southern hemispheric ice expansion is concerned exclusively with increased Antarctic sea ice extent which is the thin and seasonal ice surrounding the continent that melts away entirely in the spring and summer.  As such changes in them--whether expansion or contraction--are frequent and seasonal but do not impact climate as would changes on the Antarctic mainland  (which contribute to sea rise) or in the Arctic sea ice (which offer albedo for temperature regulation).  But at any rate--according to NASA and BAC, the continent of Antarctica is currently neither expanding nor decreasing but is still a serious concern due to structural and depth changes occurring in the cracks and disintegrations of the Antarctic Peninsula and other portions of Western Antarctica. 

Contextualizing this data from a wider frame of reference would be counter to Mr. Bolt's agenda, which evidently is to cherry-pick data and exclude other data to prove that "'melting polar ice caps' is a myth."  This can be achieved by taking superficial measurements between the Northern and Southern Hemisphere (or focusing on Antarctic sea ice extent and ignoring the disintegration of the Wilkins ice shelf in the West). 

The fact that a slight increase in sea ice extent in the Southern hemisphere (seasonal ice) has been detected for decades is something that has been long-known among scientists but is ultimately far less significant than the fact that year-round Arctic ice providing albedo protection and temperature regulation has been in a rapid decline for many decades, or that large ice shelves are disintegrating in West Antarctica and contributing to instability, glacial run-offs, and sea rise.  At any rate, sea ice extent--which encompasses sea ice in addition to the open water surrounding individual sea ice--is predominantly what Antarctic ice growth is about.  This has little if anything to do with melting polar caps, which is more concerned with thicker solid ice (e.g. glaciers, ice shelves, very thick ice sheets) or sometimes ice bergs (which are floating ice from glacial melt) and/or thicker sea ice that last year-round (such as Arctic sea ice) and not the seasonal thin Antarctic ice that is floating on water.  We therefore must go beyond Bolt's superficial analyses to get a wider and deeper picture of what is really going on beneath and beyond the surface exterior.

My source:

Source: National Snow and Ice Data Center (NSIDC)

Quick Facts on Arctic Sea Ice

What is sea ice?

Sea ice is frozen ocean water. It forms, grows, and melts in the ocean. In contrast, icebergs, glaciers, and ice shelves float in the ocean but originate on land. For most of the year, sea ice is typically covered with snow.

Why is Arctic sea ice so important?

Arctic sea ice keeps the polar regions cool and helps moderate global climate. Sea ice has a bright surface, so 80 percent of the sunlight that strikes it is reflected back into space. As sea ice melts in the summer, it exposes the dark ocean surface. Instead of reflecting 80 percent of the sunlight, the ocean absorbs 90 percent of the sunlight. The oceans heat up, and Arctic temperatures rise further.

A small temperature increase at the poles leads to still greater warming over time, making the poles the most sensitive regions to climate change on Earth. According to scientific measurements, both the thickness and summer sea ice extent in the Arctic have shown a dramatic decline over the past thirty years. This is consisistent with observations of a warming Arctic. The loss of sea ice also has the potential to accelerate global warming trends and to change climate patterns.

 

 

 

Has the Arctic Ocean always had ice in summer?

We know for sure that at least in the distant past, the Arctic was ice-free. Fossils from the age of the dinosaurs, 65 million years ago, indicate a temperate climate with ferns and other lush vegetation.

Based on the paleoclimate record from ice and ocean cores, the last warm period in the Arctic peaked about 8,000 years ago, during the so-called Holocene Thermal Maximum. A recent study suggests that 5,500 years ago, the Arctic had substantially less summertime sea ice than today. However, it is not clear that the Arctic was completely free of summertime sea ice during this time.

The last time that scientists can say confidently that the Arctic was free of summertime ice was 125,000 years ago, during the height of the last major interglacial period, known as the Eemian. Temperatures in the Arctic were warmer than now and sea level was also 4 to 6 meters (13 to 20 feet) higher than it is today because the Greenland and Antarctic Ice Sheets had partly melted. Because of the burning of fossil fuels, global averaged temperatures today are getting close to the maximum warmth seen during the Eemian. Carbon dioxide levels now are far above the highest levels during the Eemian, indicating there is still warming to come.

According to analyses at NASA, 2007 was the second-warmest year globally in the instrumental record; the Arctic was especially warm.

Related question:


How do we know human activities cause global climate change?

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Will the ice at the North Pole melt?

Sometimes in everyday use, people associate “the North Pole” with the entire Arctic region. However, when scientists discuss the North Pole, they mean the geographic North Pole, a single point on the globe located at 90 degrees North. The term “Arctic” generally refers to a much larger region that encompasses the northern latitudes of the globe. The Arctic includes regions of Russia, North America, and Greenland, as well as the Arctic Ocean.

Early in the summer of 2008, there were reports that the ice at the North Pole may melt away completely during the summer of 2008. While the possibility existed that the geographic point at the North Pole could be ice-free in summer at some point, NSIDC scientists did not made an official statement as to whether this might happen. The scientific community has a range of predictions concerning when we could see an ice-free Arctic Ocean in summer. It could be as early as 2013 or as late as 2100. NSIDC’s projections generally fall somewhere in the lower half of this range.

Related questions:

What is the gray circle in the middle of the extent map?
Then how will we know if ice at the North Pole melts?

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Why don’t I hear much about Antarctic sea ice?

NSIDC scientists do monitor sea ice in the Antarctic, and sea ice in the Antarctic is of interest to scientists worldwide. While many have published peer-reviewed journal articles on the topic, it has received less attention than the Arctic. There are several reasons for this.

Unlike Arctic sea ice, Antarctic sea ice disappears almost completely during the summer, and has since scientists have studied it. Earth’s climate system over thousands of years has been "in tune" with this annual summertime disappearance of Antarctic sea ice. However, satellite records and pre-satellite records indicate that the Arctic has not been free of summertime sea ice for at least 5,500 years and possibly for 125,000 years. So Earth’s climate system and ecosystems, as they exist today, did not develop in conjunction with an ice-free Arctic. Such an ice-free Arctic summer environment would be a change unprecedented in modern human history and could have ramifications for climate around the world.

In March 2008, Antarctica experienced a record maximum.

For more information, read Is wintertime Antarctic sea ice increasing or decreasing?

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Is wintertime Antarctic sea ice increasing or decreasing?

Wintertime Antarctic sea ice is increasing at a small rate and with substantial natural year-to-year variability in the time series. While Antarctic sea ice reached a near-record-high annual minimum in March 2008, this does not indicate a significant long-term trend. To borrow an analogy from sports, one high day, month, or even year of sea ice is no more significant than one early-season win would be in predicting whether the hometown team will win the Super Bowl ten seasons from now.

Another important point is that the increase in Antarctic sea ice extent is not surprising to climate scientists. When scientists refer to global warming, they don’t mean warming will occur everywhere on the planet at the same rate. In some places, temporary cooling may even occur. Antarctica is an example of regional cooling. Even our earliest climate models projected that Antarctica would be much slower in responding to rising greenhouse gas concentrations than the Arctic. In large part, this reflects the nature of the ocean structure in Antarctica, in which water warmed at the surface quickly mixes downward, making it harder to melt ice.

In terms of sea ice, climate model projections of Antarctic sea ice extent are in reasonable agreement with the observations to date. It also appears that atmospheric greenhouse gases, as well as the loss of ozone, have acted to increase the winds around Antarctica. Perhaps counter intuitively, this has further protected the Antarctic from warming and has fostered more ice growth.

The one region of Antarctica that is strongly warming is the Antarctic Peninsula, which juts out into the Atlantic Ocean and is thus less protected by the altered wind pattern. The Antarctic Peninsula is experiencing ice shelf collapse and strongly reduced sea ice.

Finally, even if wintertime Antarctic sea ice were to increase or decrease significantly in the future, it would not have a huge impact on the climate system. This is because during the Antarctic winter energy from the sun is at its weakest point; its ability or inability to reflect the sun’s energy back into space has little affect on regulating the planet’s temperature.

For more information, see All About Sea Ice: Arctic vs. Antarctic and the State of the Cryosphere: Sea Ice. To see data on Antarctic sea ice, see the Sea Ice Index.

Related questions:
Is Arctic sea ice really declining?
2008 had more sea ice than 2007; why?
Has the Arctic Ocean always had ice in summer?

Source: FAQ

 

Arctic and Antarctic Sea Ice Extent, 1979-2007: Although Arctic sea ice extent underwent a strong decline from 1979 to 2007, Antarctic sea ice underwent a slight increase. The Antarctic ice extent increases were smaller in magnitude than the Arctic increases, and some regions of the Antarctic experienced strong declining trends in sea ice extent. See the Arctic Sea Ice FAQ for more information. Image provided by National Snow and Ice Data Center, University of Colorado, Boulder. 

Argument 3a: "Polar caps are melting" is a myth because as for the Arctic, wrong again. 
 

The graph directly above only goes up to 2007. Since that time, I am pleased to confirm Mr. Bolt's claim that Arctic sea ice extent has made a near-"recovery" from the previous two years in terms of extent. Of course, the previous two years were an anomoly (as the linear line indicates). And there's still the La Nina anomoly and other natural variations to acknowledge for the recovery back to pre-2007 declines. Hopefully La Nina (which has or is now subsiding, I believe) will continue to provide relief to permit the current fragile recovery of Arctic sea ice to maintain some stability throughout the summer months to survive in the winter and recover more ice thickness and stability. 
 
I should also point out that two years is not enough to separate the data from the noise. A more serious concern to scientists is that we're still on a downward linear slope overall (see graph above) in terms of Arctic sea ice extent. But even more concerning is the fact that 90% of this recovery exists in the form of new, thin ice. Less than 10% of all current Arctic sea ice is thicker, older ice, based on latest measurements. This is a significant decrease from previous decades when older ice accounted for 30%-40% of all Arctic ice. Since the 1950s-19 s, Arctic ice has lost over 1 meter in thickness. So this means that not only is Arctic sea ice losing extent over the long term--but is also losing depth as well and will very likely become seasonal surface ice before long like Antarctic sea ice. 
 

Argument 3b: "Polar caps are melting" is a myth because the Arctic ice cap shrank badly two summers ago after years of steady decline, but has since largely recovered. Satellite data from NASA’s Marshall Space Flight Centre this week shows the Arctic hasn’t had this much April ice for at least seven years. 
 

I could not find any data from NASA’s Marshall Space Flight Centre to confirm this. Again, I find it interesting that the main NASA site--which has all kinds of climate data--isn't ever cited by Mr Bolt as a reference. But I've no reason to dispute the data itself based on other data sources for current trends.  However, based on Norway's Nansen satellite data (located toward the bottom of post--which he uses to disprove melting polar caps in his next argument), the Arctic hasn't had this much ice in about four years (~2005), not the seven years as Mr. Bolt's Marshall satellite claims.  Were it seven years, this would put us back to 2002 levels--which is not the case (as graph below, updated daily and taken a few days ago from a satellite--demonstrates compared to 2002).  At any rate, 2002 and 2005 are ultimately insignificant in terms of long-term climatic trends, but just thought I should point out the discrepancy between his one satellite source and his other one, since "seven years" seems profoundly significant and meaningful to most.   

 

 
Figure 2. The graph above shows daily sea ice extent as of May 3, 2009. The solid blue line indicates 2009; the dashed green line shows 2007;and the solid gray line indicates average extent from 1979 to 2000. The gray area around 1979-2000 average line shows the two standard deviation range of the data. Sea Ice Index data.
—Credit: National Snow and Ice Data Center

High-resolution image

 

 

 

 

Conditions in context

The decline rate for the month of April was the third slowest on record. The Arctic lost sea ice cover at a rate of 27,300 square kilometers per day (10,500 square miles), compared to an average of 41,600 square kilometers (16,000 square miles) per day for 1979 to 2000. Ice extent was well above normal in the Bering Sea, but below normal in the Barents Sea and the Sea of Okhotsk.

For the past few years, Arctic sea ice extent for most months has been more than two standard deviations below the 1979 to 2000 mean, particularly in summer. Two standard deviations provide an estimate of the expected range of natural variability. Because of cooler than average temperatures, Arctic sea ice extent at the end of April 2009 was within the expected range of natural variability.

 

 

 
Figure 3. Monthly April ice extent for 1979 to 2009 shows a decline of 2.8% per decade.
—Credit: National Snow and Ice Data Center courtesy NOAA/ESRL Physical Sciences Laboratory

High-resolution image
 

 

April 2009 compared to past Aprils

Compared to previous Aprils, April 2009 is near the middle of the distribution (10th lowest of 31 years). The linear trend indicates that for the month of April, ice extent is declining by 2.8% per decade, an average of 42,400 square kilometers (16,400 square miles) of ice per year.
 

What I would question is the significance of this recovery in light of many decades which show an unmistakable downward linear trend. This linear line is is based on averages to smooth out monthly or yearly anomolies, but is undeniably going downward toward decline over longer spans of time.  It isn't logical to conclude that a wiggle here or a blip there (1998 is a fave blip among skeptics and deniers, for example) is "proof" of a sudden reversal in trends to show that global warming is a myth after so many decades of declines in a downward linear direction with respect to Arctic sea ice decline--which continues to trend down long-term although there are, through the years, many large wiggles both up and down.  Conversely, the linear trend for temperature rise has been steadily rising over the long term in spite of 1998 being the record-high temp, according to many data sources (2005 was the record-high, according to other sources).  There's also an upward linear trend in terms of CO2 or other greenhouse gas concentrations although 2008 showed a decrease in linear rise in CO2 concentrations because of global recession).. So I wouldn't read too much into a recovery from a two-year anomoly or even from a longer time frame, such as 10 years.  It's very difficult to distinguish long-term patterns from noise in such a small time-frame.

Based on other data, the recovery appears to be a return to early 2000s levels, but not back to 1979, for instance. A graph of yearly sea ice extent from 1979 to 2009 rather than a mean (unless the mean is taken from shorter durations and more than one mean is plotted--such as below) would provide a more meaningful picture of current conditions with long-term climatic trends. 30 years is the minimum number of consecutive years of data to be analyzed from the standpoint of climate. Anything less than a 30-year period is "weather." Thus, those who attempt to extrapolate and cherry-pick non-averaged data from shorter durations to draw any conclusions on global climate change (whether for or against) aren't engaged in climatology but in politics mixed with a bit of "weather," sports, the stock market, sensationalism, and other news. But I expect that from Mr Bolt since he is a newspaper columnist, after all.
 

Arctic Sea Ice Extent Standardized Anomolies, Jan. 1953 - Oct. 2008
 

http://nsidc.org/sotc/sea_ice.html
 

 
 

Argument 4. "Polar caps are melting" is a myth because Norway’s Nansen Environmental and Remote Sensing Centre says the ice is now within the standard deviation range for 1979 to 2007. 

Yes, Nansen shows that 2009 is within the standard deviation range for 2009-2007 (see graphs below for Nansen).  As the graph above demonstrates (which is offered for a picture of longer-term trends extending back to 1953), there are indeed large variations up and down from year to year in terms of sea ice extent, represented by the wiggly lines going up or down from year to year (or every five years).  Yet taken as a whole, they are going ever downward by linear trend, when smoothing out for anomolies and taking averages.  Or even when not looking at the linear smoothed-out line but focusing on the wiggly line jumping up and down instead, the trend is in a definite downward slope.  To argue otherwise is foolish.  Of course, it doesn't show the latest data from 2009 which would plot the current sea ice extent as a wiggle upward to the standard deviation range for 1979-2007.  Why I'm including the chart above is to put this "recovery" in the context of long-term climatic changes going back to 1953.  This year's recovery is actually a return to ~2005 levels (not included in graph above).  Thus, while certainly within the standard deviation range for 1979-2007-- the current recovery is still 2-3 standard deviations below the 1968-1998 mean and 3-4 standard deviations below that of Arctic sea ice extent in 1953. 

I see no reason to suppose that based on Nansen's chart of this year's Arctic sea ice extent indicating "within the standard deviation range for 1979-2007" (just barely--using a different kind of measurement instead that measures sea ice area--and not sea ice extent--) that this recovery will mean a spectacular turn-around and directional shift in sea ice extent from this year forward showing a permanent upward linear trend to pre-industrial levels, after so many decades of decline.  So his claim is still falsehood.  
 

Mr. Bolt's source:

nansen: http://arctic-roos.org/observations
 

Daily Updated Time series of Arctic sea ice area and extent derived from SSMI data provided by NANSEN.

Ice extent is the cumulative area of all polar grid cells of the Northern Hemisphere that have at least 15% sea ice concentration, using the NORSEX algorithm. Ice area is the sum of the grid cell areas multiplied by the ice concentration for all cells with ice concentrations of at least 15%. Ice extent and ice area are calculated for a grid resolution of 25 km. The difference between area and extent for our data is always positive. This difference represent the area of the open water in the pixels partly covered by ice (i.e. ice concentration less than 100%). In other words, ice area takes into account that there is a fraction of open water in pixels with ice concentration above 15 % and below 100 %". Ice extent does not include this effect and gives therefore a higher number of square km than ice area.

Daily Updated Time series of Arctic sea ice AREA derived from SSMI data 
 

 
 

Daily Updated Time series of Arctic sea ice EXTENT derived from SSMI data 
 

 

Monthly Deviations of Sea Ice AREA in the Arctic from merged SMMR and SSMI Data (NORSEX algorithm)
 

 

Monthly Deviations of Sea Ice EXTENT in the Arctic from merged SMMR and SSMI Data (NORSEX algorithm)
 

 

Nansen Environmental and Remote Sensing Centre says the ice is now within the standard deviation range for 1979 to 2007 for sea ice AREA, but not for sea ice EXTENT (which is the measurement that Mr Bolt bases his other data on).  IF you're going to use one type of measurement, you should be consistent all the way through or, at the very least, be honest and indicate what type of ice measurement you are referring to in each claim unless you do not know the difference (which in Mr. Bolt's case, seems to be the latter).  It is not surprising that Mr. Bolt would switch to sea ice area to show recovery since it is, after all, the one that can show the "now within the standard deviation range" whereas sea ice extent cannot show this to be the case.  Conversely, a measurement of "sea ice extent" can reveal that Antarctica has grown remarkably by 100,000 square kilometers per decade (since this calculation includes sea water surrounding sea ice)--but a measurement of "sea ice area" would reveal that this growth is considerably below the 100,000 square miles I mean kilometer per decade expansion (see the difference different units of measure can make?  That was a mistake on my part when I said, "miles"..).  But, at any rate--I hope that if there is anything we get from all of this--is that growth of Antarctic sea ice does not contribute to climate change for the better or for the worse and is not "polar caps," so his argument is irrelevant to disprove it on that basis.  Based on Nansen data, there is still a 4% decline in Arctic sea ice from 1980-2009--in spite of a recovery back to pre-2007 levels.

 

Concluding thoughts

It's just a falsehood...

The Orange Inquisition is upon us. Good science is being convicted and executed in the court of public opinion.

Mr Bolt evidently believes that polar caps are two-dimensional surface planes on either pole such that the disintegration of glaciers and year-round ice doesn't matter, so long as their surface extent is offset by new surface growth down in the Antarctic and recovery of Arctic ice to pre-2007 declines to show that polar caps aren't melting horizontally, from a surface glance (irrespective if they are seasonal or year-round ice to provide temperature regulation, or whether the melting of older ice can lead to sea level rise..).  Legitimate science tried to explain otherwise but it takes too long to pay attention, "so 'surfaces, surfaces, surfaces' was all that they saw..."