Averaging together antarctic and arctic sea ice hides an important truth

By: Dr. Jeff Masters , 2:37 PM GMT on January 15, 2009

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Since my last post designating arctic sea ice loss as the top climate story of 2008, I've heard a lot comments like this one: "Jeff, you just can't seem to understand the that man-made global warming is a fable and complete hoax. In all that blathering about the falsified IPCC reports and the study of the arctic ice sheet, you somehow neglected to mention that the ice recovered not only what it lost last year, but is now larger than the previous known record measured in 1978".

Well, I can understand this point of view, given complexity of the climate change issue, and the large amount of conflicting information one sees in the media. Let's look at the facts about global sea ice. You can look at the data yourself at the excellent University of Illinois Cryosphere Today web site. Reliable sea ice records go back to 1979, when satellite measurements began. Antarctic sea ice reached its greatest extent on record during the winter of 2007. Summertime ice coverage also increased in 2007-2008 compared to 2006 levels (Figure 1). However, as one can see from Figure 1, there is high variability in antarctic sea ice from winter to summer, and antarctic sea ice can best be described as having stayed constant since 1979 (as stated in the 2007 report of the Intergovernmental Panel on Climate Change (IPCC). The IPCC did find that there had been a significant decline in arctic sea ice, in all seasons, between 1979-2006. Despite this decline, there have been three periods during the past two years when the sum of the arctic and antarctic sea ice was the same or even higher than it was at the start of the satellite era (1979). An article published January 1 on Daily Tech noted that "global sea ice levels now equal those seen 29 years ago". This was pretty close to the truth on December 31, 2008, despite the fact that arctic ice was 1 million km^2 below 1979 levels, since antarctic ice was 0.5 million km^2 above 1979 levels. Although arctic sea ice extent has steadily declined since 1979, especially in summer, this decline is not as great during the winter months. One can find periods in winter when summing together antarctic and arctic sea ice area makes it appear that arctic sea ice loss is no big deal.

However, this is the wrong way to look at the issue. We don't care much about global sea ice in winter. We care about arctic sea ice in the summer. Sharp declines in summertime arctic ice are likely to cause significant and damaging alterations to Earth's climate. Cleverly quoting irrelevant facts about global wintertime sea ice data to hide the summertime loss of arctic sea ice is a tremendous disservice. It's like hiding the potential impact of a major hurricane in a one-week forecast by saying, "the average peak wind speed for the next seven days will be 17 mph", and neglecting to mention that the wind will be calm six of those days, but 120 mph on the other day. The loss of arctic sea ice the past two summers, is, in my view, the most important human-caused climate change event yet--even more significant and dangerous than the opening of the antarctic ozone hole in the 1980s. It's great that we're not seeing loss of sea ice in Antarctica. But, both the Antarctic and the Arctic can be thought of as important internal organs in our living Earth. The fact that the Antarctic has not undergone significant warming and sea ice loss in no way diminishes the urgency with which climate scientists view the diseased state of our Arctic. Fully 88 presentations on arctic sea ice were made last month at the world's largest scientific climate change conference, the American Geophysical Union (AGU) meeting in San Francisco. None of these scientists averaged together the arctic and antarctic sea ice together to show that the overall state of Earth's cryosphere was a healthy one. There was widespread concern for the health of the Arctic among all the scientists I spoke with, and none of the speakers at the talks I attended expressed the idea that the recent melting of arctic sea ice was predominantly natural, with human-caused climate change an insignificant factor. One view (Stroeve et al., 2007) is that human-emitted greenhouse gases are responsible for 47-57% of the arctic sea ice loss since 1979. Heat-absorbing black soot from fires and pollution settling on the white ice is thought to also be a significant contributor.


Figure 1. Antarctic sea ice area as observed via satellite since 1978. The maximum area in winter has ranged between 14-16 million square kilometers, about the same amount of ocean that the Arctic ice covers in winter. However, the antarctic sea ice almost entirely melts away in summer, something the Arctic sea ice does not do (yet). Antarctica is a huge continent that rises thousands of feet above the ocean. It holds about 90% of the world's fresh water, locked up in its massive ice cap. The presence of such a titanic block of ice at the bottom of the world completely dominates the weather and climate of the region, and the year-to-year fluctuations of sea ice don't have a lot of impact on temperatures there. Image credit: University of Illinois Cryosphere Today.

What is the current state of Antarctic climate?
At the December 2008 AGU meeting, scientists gave Antarctica a mixed bill of health. Isabella Velicogna of UC Irvine reported that satellite gravitational variation measurements of Antarctica's ice cap showed significant loss of ice between 2002-2008, but that the large natural variations in melting with the seasons made it difficult to be confident of the results. A somewhat different result was reported by J. Zwally of NASA. Using data from a higher-resolution satellite-borne laser altimeter, he found that there was no major loss of Antarctica's ice sheet between 2003-2007. Regardless of which data set is correct, Antarctica is in better shape than the Arctic because Antarctica has stayed relatively cool in recent decades (Figure 2). For example, the surface temperature at the South Pole cooled 0.05° C between 1980 and 1999 (Kwok and Comiso, 2002). The majority of Antarctica has shown no statistically significant warming over the past 50 years (Turner et al., 2005), and cooling has just been dominant between 1982-2004. In the period 2004-2007, much of the Antarctic warmed (Figure 3), but it is too early to say if this is the beginning of a warming trend. Check out the January 22 issue of Nature when new results about whether or not Antarctica is warming will be published.


Figure 2. Antarctic surface temperatures as observed via AHVRR satellite measurements between 1982 and 2004. Much of Antarctica cooled during this period. Image credit: IPCC The Physical Science Basis, Figure 3.32.


Figure 3. Antarctic surface temperatures as observed via AHVRR satellite measurements between 1981 and 2007. Note that the cooling trend observed from 1982-2004 reversed, thanks to warming from 2004-2007. Image credit: NASA

Why did Antarctica cool between 1982 and 2004 if there was global warming going on?
The weather of the Antarctic is dominated by a strong band of westerly winds that blow around the pole. This circumpolar vortex extends from the surface to the stratosphere, and can attain very high wind speeds, thanks to the absence of large land masses to slow it down. This vortex tends to isolate Antarctica from the rest of the globe, keeping global warming from influencing Antarctica's weather, and allowing the surface to cool. The Antarctic Peninsula, which sticks out from Antarctica towards South America, frequently lies outside the vortex. This has allowed the peninsula to warm significantly, compared to the rest of Antarctica (Figures 2 and 3). The antarctic circumpolar vortex has strengthened in the past 25-30 years, forming an even stronger barrier than usual. Tree ring records (Jones and Widman, 2004) suggest that the circumpolar vortex has shown similar strengthening in the past, so the current cooling trend in Antarctica may be natural.

Another possibility, favored by climate modelers, is that the strengthening of the circumpolar vortex and recent cooling in Antarctica are primarily due to a combination of the recent increase in greenhouse gases and the opening of the Antarctic ozone hole. The ozone hole opened up at about the same time as the recent cooling began. Ozone absorbs UV radiation which heats the atmosphere around it, so the absence of ozone has led to cooling in the stratosphere over Antarctica. This cooling has been about 10° C in October-November since 1985 (Thompson and Solomon, 2002). This has acted to intensify the circumpolar vortex, leading to surface cooling. If the climate modelers are right, the circumpolar vortex will weaken as the ozone hole diminishes in coming decades. This will allow the Antarctic to begin warming with the rest of the globe, in a decade or two.

References and resources
Intergovernmental Panel on Climate Change (IPCC), 2007, The Physical Science Basis.

Jones, J.M., and M. Widman, "Atmospheric science: Early peak in Antarctic oscillation index," Nature 432, 290-291 (18 November 2004) | doi:10.1038/432290b; Published online 17 November 2004.

Kwok, R., and J.C. Comiso, "Spatial patterns of variability in Antarctic surface temperature: Connections to the Southern Hemisphere Annular Mode and the Southern Oscillation", GEOPHYSICAL RESEARCH LETTERS, VOL. 29, NO. 14, 10.1029/2002GL015415, 2002.

Thompson, D.W.J., and S. Solomon, "Interpretation of Recent Southern Hemisphere Climate Change", Science 3 May 2002: Vol. 296. no. 5569, pp. 895 - 899 DOI: 10.1126/science.1069270.

Stroeve, J., M.M. Holland, W. Meier, T. Scambos, and M. Serreze, Arctic sea ice decline:Faster than forecast", GRL 34 L09501, doi:1029/2007GL029703, 2007.

Turner, J. et al., 2005, "Antarctic climate change during the last 50 years", International Journal of Climatology, Volume 25, Issue 3, pp 279-294.

Arctic sea ice

"Antarctic cooling, global warming?" RealClimate.org post, 3 December 2004.

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Coming Monday: Inauguration Weather. Wednesday: is the globe cooling? A report on temperatures for 2008, merely the 9th warmest year on record.

Jeff Masters

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Midtown Manhattan
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Bone
Wonder what the water temp is. Yesterday they stopped ferry service about 40 miles north due to river ice
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117. auburn (Mod)
looking for the online scanner feed from this page
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I would think that snowfall in Antarctica might actually INCREASE with climate change. The reason: more moisture being sucked up into the southern polar front coming from warmer latitudes. The temperatures inside the vortex remain cold enough.
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115. auburn (Mod)
What county is the crash in?
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if they can get lines to it they can tow it to either red hook terminal or bayonne terminal which is where Weeks salvage is.
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Not to wax nostalgic but it appears this was a 2009 real life version of "Miracle on 34th Street"
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yea med outgoing tide at close to 10knts right now if not faster
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Plane also reported to be drifting south
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They're concerned its going to sink.
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Report that the pilot was dropped off at pier 79 and stated no one is left on the plane
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No med to vivid. Brought back to many memories =/

Will be some time before the bumps go down.

med, dont know if its on your scanner or not, just had a harbor pilot in the office saying NY Harbor patrol calling for tug boats. Seems like the want to tow it somewhere
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yea Med NY waterway and Circline were actually first responders LOL
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Bonedog,
That must have been an unbelievable sight. Goose bumps go down yet:)
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More good news
53 people on ferry being taken to Circle Line pier, 12 on the pier at 40st. it appears many rescued by commercial boats that happened to be in the area
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Member Since: January 24, 2007 Posts: 317 Comments: 31946
Pat he basically parked the plane right infront of the 39th street ferry terminal!

Like I said from my vantage point I wintessed the landing and almost as fast as the plane came to rest ferries were alongside.
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Give these pilots alot of credit for a safe water landing. From my vantage on the docks it almost looked as if he was landing on a runway yet it was the Hudson instead.
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Great Piloting to bring a Airliner down safely in a Takeoff abort..and make a safe water landing and egress of passengers.
Location made it possible for the Vessels to render quick assistance too.

Amazing scene.


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So far so good
39 passengers on 36 street, all so far being requested for them is blankets by NYFD
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97. auburn (Mod)
Jet Crash Live on CNN
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med I am on the waterfront NJ side. Office overlooks hudson, eyewitness here.

CNN already interviewing passengers, sounds like most macde it off onto NY Waterway ferries. Some passengers said cold and wet. EMS response hopefully is for exposer and not serious injuries
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US Airways Flight bound for Charlotte, NC from NY. - Plane crashed into the Hudson River. Rescue boats are on the scene but no word as to survivors or deaths. It landed in one piece. Go to Fox News for info. One theory as to why it crashed is it a flock of birds and the engines were possibly knocked out.
Member Since: January 24, 2007 Posts: 317 Comments: 31946
Anthropogenic forcing = GW...
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4 circleline(sightseeing) boats on scene making rescues
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"OK.... So, based on 31 years of data, we are entirely without-any-room-for-doubt certain that the ONLY cause for a warm up is CO2 production. Seems like a reach."

1. It certainly would be a reach if Arctic sea ice extent was the only thing we were looking at. Fact of the matter is, though, that Arctic sea ice is only a small part of the puzzle. There's many independent lines of evidence that point to a human contribution to the increase in global temperatures. I think that it would be fair to say that the loss of Arctic ice in the summer is consistent with global warming theory.

2. I haven't heard any responsible people make the claim that anthropogenic CO2 release was the only cause of the increase in global temperature over the last century. I think the language the IPCC uses is something like it is likely that most of the warming can be attributed to human activity.
Member Since: June 26, 2007 Posts: 0 Comments: 92
Listening on scanner
Plane floating south,FDNY asking for major EMS response(incident down the block from me)
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hopefully everyone is Fine. Plane is still intact and floating. multiple vessels around including harbor rescue and coast guard.

this brought back flashbacks unfortunatly =( I was in shock then amazement as the pilots brought it in for a water landing.
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flight 1549 Laguardia to Charlotte

perfect water landing
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Pardon the off topic
Plane crash in NYC's Hudson River with 151 people on board
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This is kind of funny that Dr. Masters posted this blog today. I just finished reading the book "The Little Ice Age". Some of the historical evidence for a 'Medieval Warm Period' is pretty compelling. Green pastures in Greenland, wine production in mid England...

Then, BAM, 1300 rolls around and the Earth enters a rapid cooling. Glaciers advance 'a musket shot' each year toward Alpine villages. Grape production ceases in northern climes, and even cereal crop production struggles. Norse settlements succumb to the cold.

Then, things start to warm up after 1850.

First satellite goes into orbit in the early 1960's... and we start to get reliable ice coverage figures from 1978 onward.

OK.... So, based on 31 years of data, we are entirely without-any-room-for-doubt certain that the ONLY cause for a warm up is CO2 production. Seems like a reach.

Hey, I'm all for not trashing the planet and I think we really need to break our oil habit. However, by instituting scientific dogma, aren't we leaving science to politicians?
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It appears warmer temps will come tonite in South Florida bacause of overcast skies and not allowing radiation cooling under clear skies which was initally expected.
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Quoting Drakoen:


I agree. Putting that FSU degree to good use I see lol...


Lol...

The blanket of clouds has been over us for a few days now,i suspect temps will also stay up tonight.Next week we may get a strong enough trough to push colder air down this way.
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Quoting hurricane23:
My view on temps in South Florida...

The main factor here was that the center of the polar high isn't going to penetrate too far south. That's because the
trough isn't deep or strong enough to push it southward.If the trough was a bit deeper/farther south, it would be a different story as this high is strong enough for freezing temps down into South Florida under the right circumstances.The clouds over us are another indication that the cold air isn't very deep in nature, although we'redefinitely below normal and will stay that way for a while. In fact, next week we may get a strong enough trough to push colder air down this way.

Adrian


I agree. Putting that FSU degree to good use I see lol...
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My view on slightly warmer temps in South Florida...

The main factor here was that the center of the polar high isn't going to penetrate too far south.That's because the trough isn't deep or strong enough to push itsouthward.If the trough was a bit deeper/farther south, it would be a different story as this high is strong enough for freezing temps down into South Florida under the right circumstances.The clouds over us are another indication that the cold air isn't very deep in nature, although we're definitely below normal and will stay that way for a while. In fact, next week we may get a strong enough trough to push colder air down this way
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TSUNAMI INFORMATION STATEMENT NUMBER 1
NWS PACIFIC TSUNAMI WARNING CENTER EWA BEACH HI
805 AM HST THU JAN 15 2009

TO - CIVIL DEFENSE IN THE STATE OF HAWAII

SUBJECT - TSUNAMI INFORMATION

THIS STATEMENT IS FOR INFORMATION ONLY. NO ACTION REQUIRED.

AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS

ORIGIN TIME - 0750 AM HST 15 JAN 2009
COORDINATES - 46.9 NORTH 155.2 EAST
LOCATION - EAST OF KURIL ISLANDS
MAGNITUDE - 7.5 MOMENT

EVALUATION

BASED ON ALL AVAILABLE DATA A DESTRUCTIVE PACIFIC-WIDE TSUNAMI IS
NOT EXPECTED AND THERE IS NO TSUNAMI THREAT TO HAWAII. REPEAT. A
DESTRUCTIVE PACIFIC-WIDE TSUNAMI IS NOT EXPECTED AND THERE IS NO
TSUNAMI THREAT TO HAWAII.

THIS WILL BE THE ONLY STATEMENT ISSUED FOR THIS EVENT UNLESS
ADDITIONAL DATA ARE RECEIVED.

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Magnitude 7.4 - EAST OF THE KURIL ISLANDS
2009 January 15 17:49:39 UTC
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Quoting IKE:


It is not going to snow in Florida.


I second that notion; though, there a few off-shore showers showing up on the radar out of Tallahassee. If they stick around overnight something could happen...
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78. Skyepony (Mod)
Polar vortexs, when they get going make it down right cold regardless of CO2. The NH one when it's churning it's cold, but it moves around more. Where it doesn't cover shows significant warming, so the NH wobble warms a larger area some VS Antartic where the small peninsula takes a bigger warming brunt. The SH vortex stays put more so a large area gets cut off from the rest of the world's particles & soot as well. The rest of the SH is feeling it.

link
Member Since: August 10, 2005 Posts: 225 Comments: 39388
Quoting Skyepony:
Tropical RAMSDIS just moved floater 1 to the surface trough east of the Antilles


Nothing really interesting there but some scattered thunderstorm activity for puerto rico.
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"Sorry, with Dr M's blog detailing the hole as the primary masking process of CO2-induced warming...you get the idea."

Which blog are you talking about? The one above makes no mention of a masking of CO2-induced warming. The masked warming thing is your invention. Second, Dr. Masters mentions the ozone hole as a potential cause of cooling in Antarctica, not the primary cause. Seems to me that he places more emphasis on the circumpolar vortex blocking heat flow from lower latitudes to the polar region.
Member Since: June 26, 2007 Posts: 0 Comments: 92
That low kinda looks like barry
Snow possibly on Sun Mon and Tue
snow day?!?
Member Since: March 29, 2008 Posts: 0 Comments: 2377
Quoting Skyepony:
Tropical RAMSDIS just moved floater 1 to the surface trough east of the Antilles


Now that is interesting.
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73. Skyepony (Mod)
Tropical RAMSDIS just moved floater 1 to the surface trough east of the Antilles
Member Since: August 10, 2005 Posts: 225 Comments: 39388
Quoting AtsaFunnyToo:
"I cannot go along with the SH ozone hole existing for a month masking the supposed effect of CO2 all year long and the NH Arctic being the location singularly affected the most by the global (everywhere) CO2 concentration increase."

I actually didn't say anything about the ozone hole. My comments were related to albedo and the circumpolar vortex. Curious though, where did you come up with the idea the the Antarctic ozone hole was limited to 1 month out of the year?


Sorry, with Dr M's blog detailing the hole as the primary masking process of CO2-induced warming...you get the idea.

The albedo and the vortex alone cannot fully explain the differences in temperature trends in the NH and SH.

The O3 hole duration: Of course, it varies year-to-year, and the definition of 'hole' plays a part. I see some sites that call it a hole when the O3 concentration drops below 50% the norm and others more stringent. Some call it a month, some say it is sometimes present for 3 months.

It is never all year long. The vortex and polar stratospheric clouds (that provide surfaces for the chemistry...analogous to cloud nuclei) do eventually break up...1 to 2 months after sunlight hits the stratosphere following winter.
Member Since: August 16, 2007 Posts: 6 Comments: 12463
"I cannot go along with the SH ozone hole existing for a month masking the supposed effect of CO2 all year long and the NH Arctic being the location singularly affected the most by the global (everywhere) CO2 concentration increase."

I actually didn't say anything about the ozone hole. My comments were related to albedo and the circumpolar vortex. Curious though, where did you come up with the idea the the Antarctic ozone hole was limited to 1 month out of the year?
Member Since: June 26, 2007 Posts: 0 Comments: 92
Quoting AtsaFunnyToo:
"So long as the temperature is above absolute zero (a. k. a. -273.15 C) longwave radiation is always emitted."

But the intensity of IR emissions is temperature dependent. That's why I said that little IR (relatively) was emitted from the surface. My point was that under these conditions, the effect of increased atmospheric CO2 concentrations might be below a detection threshold. As to your comment about glacier/snow covered areas outside of Antarctica - these areas aren't isolated from global circulations by the circumpolar vortex.


Ahh, but they are, in the Arctic. Not as isolated nor for as long, mind you, but it does happen in the NH, too. The Arctic has ozone holes of lesser size, severity, and duration, too! In Feb/March, I think.

I cannot go along with the SH ozone hole existing for a month masking the supposed effect of CO2 all year long and the NH Arctic being the location singularly affected the most by the global (everywhere) CO2 concentration increase.
Member Since: August 16, 2007 Posts: 6 Comments: 12463
Can you imagine conducting science in a labratory like some of this... throwing volitile test tubes at each other, using squirt guns filled with deadly biological microbes, or using petre dishes like some kind of mine field for the enemy scientists...

isn't that a new game show on Fox?
Member Since: January 24, 2007 Posts: 317 Comments: 31946

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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