Averaging together antarctic and arctic sea ice hides an important truth

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

Share this Blog
5
+

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.

Volunteers needed for disaster relief fund-raising
The portlight.org disaster relief charity is in the process of wrapping up its Hurricane Ike relief efforts, and is looking ahead to the future. According the new wunderground featured blog, Portlight Disaster Relief, "Our goals are to expand our network of supporters, continue to create a sense of ownership and community and create a financial reserve. Achieving these goals is critical to us being able to serve future hurricane victims in a strategic, pro-active and efficient manner." To this end, Portlight is sponsoring a fund-raising effort this March and April in 40 cities--a Spring Relief Walk. Volunteers in twenty cities have already committed to the effort, and more volunteers are needed! Check out the Portlight Disaster Relief blog for more information.

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

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 169 - 119

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8Blog Index

OK, how about another theory on the shrinking ice: I think it's probable that with all the profit taking of the natural resources available a large part of the shrinking ice is due to "Icebreaker ships". They keep building them bigger and stronger, going where no man has gone before, and thus opening holes in the ice that were never there in the past. Cruising around in these ice fields keeps them broke up and a goodly portion of the ice just floats away. Another goodly portion has more exposed edges to melt or be affected by the ocean and wave action.
You know the same people chasing the Polar Bears use this equipment. Probably scare off a few pounds of bear meat every time they get close to one, along with a potential meal for the bear.
The tourist season brings these boats and others to the base of Glaciers adding to the problem by helping to wear away at the base and allowing the higher ice to hurry itself on down to the sea.
And then maybe it’s all for naught as this record breaking cold weather may put enough ice up there to hold out for quite a while!
Just a thought,
Member Since: Posts: Comments:
There is a definite red flag warning for all counties(excluding the lower keys) in Florida as dewpoints are foretasted to bottom out in the negative single digits with relative humidities in the single digits for several hours(Lake Okeechobee northward with a lesser extent southward)! Hard to imagine a RFA with daytime highs expected in the lower fifties tomorrow under sunny skies.
Member Since: Posts: Comments:
MichaelSTL banned me from his blog because I don't agree with him about Global Warming....so, what club did I just join, and how many members are there now?

;)
Member Since: Posts: Comments:
Quoting all4hurricanes:
yikes a plane crashing into Hudson bay It seems scary but everyone lived and they said on the news the hasn't been an avaiton fatality in two years that gives me a lot of confidence in air travel.

and to think that im looking at the Hudson River from my window
Member Since: Posts: Comments:
yikes a plane crashing into Hudson river It seems scary but everyone lived and they said on the news the hasn't been an avaiton fatality in two years that gives me a lot of confidence in air travel.
Member Since: Posts: Comments:
164. HadesGodWyvern (Mod)
sorry that was a couple of hours ago.. but still is news
Member Since: May 24, 2006 Posts: 50 Comments: 45273
163. HadesGodWyvern (Mod)
Australian Government Bureau of Meteorology


MEDIA:

NO USE OF STANDARD EMERGENCY WARNING SIGNAL (SEWS)

PLEASE BROADCAST THIS INFORMATION IF REFERRING TO THE EARTHQUAKE IN NEWS

REPORTS.

********************************************************************************


NO TSUNAMI THREAT TO AUSTRALIA


Issued by the Joint Australian Tsunami Warning Centre (JATWC) at 05:06 AM EDT

on Friday 16 January 2009


********************************************************************************

SUMMARY:


An undersea earthquake of magnitude 7.5 has occurred at 04:49 AM EDT on Friday

16 January 2009 near KURIL ISLANDS REGION.


THERE IS NO TSUNAMI THREAT TO THE AUSTRALIAN MAINLAND, ISLANDS OR TERRITORIES.


No further updates will be issued unless the situation changes.

Member Since: May 24, 2006 Posts: 50 Comments: 45273
Re: Plane Crash.
To land an aircraft, on water, 3 mins. after takeoff, WITH NO POWER, and to put it down so sweetly, is an INCREDIBLE ACHIEVEMENT.
Those things dont fly without engine power. Great Stuff man.
Member Since: October 24, 2005 Posts: 0 Comments: 24307
33. Here's my theory: global warming and cooling are natural cycles. They would happen independently of mankind's involvement. AGW and AGC are also happening concurrently due to the fact that more than 6 billion people live on the Earth. Co2 emission isn't the only variable that is caused by man though. Reducing emissions(not just co2) might buy us a little time though if we could do it on a global scale.

The theory continues: as the ice melts in the North and the snow and ice accumulate in the South the Earth is thrown of balance. This is also theorized as a natural phenomenon. We just might be speeding it with our contributions.

To test the theory all we have to do is keep doing what we're doing. Not very scientific, but apparently very few people here seem to trust the current experts anyway.

We would need another global climate with the same population of people that drastically changed their current energy practices to really test the theory. Let's call our current Earth the control group.

Then we just monitor both to see what happens. In order to prove the theory we would need at least 14 globes I suppose. 7 controls and 7 experimentals. That way we could get really good statistics out of the experiment.

I'd be willing to accept grant money for this project if any of you are interested. lol

Just kidding... I am a plant scientist. We see many changes occuring related to this subject. Especially were plants grow that they never used too.

By the way in response to a previous poster: I'm pretty sure the global algae population uses far more co2 than it releases.

Unfortunately, due to rising temperatures in the oceans the balance of phytoplankton - that absorb most of the co2 in the natural cycle - to other ocean going zooplankton - that release co2 - may be thrown off. It could swing either way though. More algea or more of either critter could be a bad thing for the complex system of life in the oceans - which we (the world) depend on as a major food source.

Again, all just theories of mine.

If anyone who can make several copies of planet Earth please let me know. I'll also need some master orators to convince seven world populations to stop polluting their worlds. Maybe we can get Fire to donate his big v8 truck to help haul them.
Member Since: Posts: Comments:
Well, they are beginning to release many emergency service units back into regular service. Looks like things are winding down. NYPD states all travel restrictions over, all streets being reopened. Gotta go chill for a while. Pleasure talking to ya'll. Have a wonderful and peaceful night.
BTW Bone I have a couple extra Valium I'd gladly share with ya:)
Member Since: Posts: Comments:
Conchy,
One positive flashback. On 9/11 over half-million people were evacuated from Manhattan south of the towers making it the second largest evacuation by water in history(the evacuation of 800,000 Allied troops at Dunkirk during World War 2 was the largest).
And it was performed by civilian water craft after a call for assistanced was put out by the Coast Guard. No one was hurt in the process and it was all performed without a plan. So kudo's also go to New York's Sea-men and sea-women

Member Since: Posts: Comments:
Quoting Bonedog:
conchy the goose bumps we are talkign about are 9/11 flashbacks =( this was eerily similar in many ways for me at least.
Ah, didn't even think about that but of course those of you up there that would be the first thing through your minds.
Member Since: Posts: Comments:
but yes goose bumps for those passengers for sure not knowing what was going to happen
Member Since: Posts: Comments:
conchy the goose bumps we are talkign about are 9/11 flashbacks =( this was eerily similar in many ways for me at least.
Member Since: Posts: Comments:
yea Med he was a true professional. Took the time to make sure the plane was clear and that also means he was last off. Captain didnt have to go down with this ship fortunatly
Member Since: Posts: Comments:
Quoting medicroc:
Reported before that the captain stated to NYFD that there was no one left on board. So this guy lands a plane in the water and while its threatening to sink checks the entire plane before he leaves to make sure there is no one left on it. Man would I like to meet this guy.
He deserves something very special and I hope the folks on the plane will realize how very fortunate they were to have such a crew. Wow - goose bumps for sure.
Member Since: Posts: Comments:
if they get it to Weeks I will go and get some shots tomorrow
Member Since: Posts: Comments:
Reported before that the captain stated to NYFD that there was no one left on board. So this guy lands a plane in the water and while its threatening to sink checks the entire plane before he leaves to make sure there is no one left on it. Man would I like to meet this guy.
Member Since: Posts: Comments:
stop med goose bumps finally went down

yea conchy cudos to the crew for the evac and the piolt to land on zero power and do it text book.
Member Since: Posts: Comments:
Wow Bone - didn't even think about the luggage and the air in the compartment. Kudos to the crew - bet they are so relieved. Had to be some tense moments.
Member Since: Posts: Comments:
Bone,
Just remembered something I heard over the scanner about an hour ago. Plane took off with 21,ooo gallons of fuel. In the air just a few minutes.
There go the goose bumps again
Member Since: Posts: Comments:
he came in over the GW Bridge. I think I would have crapped my pants if I was on the bridge when he did that!
Member Since: Posts: Comments:
LOL med more like crawl hour nightmare. West side highway has to be closed right now and probably some cross streets as well. Varazano has to be bumper to bumper, great view from there!
Member Since: Posts: Comments:
they are trying too conchy. They have the eqjuipment in place to do so. Lugage might be fine also, thats the only way this plane is still floating if the baggage compartment still has air in it.


med FAA saying BOTH engines were out do to bird strike. This guy landed with ZERO power!! Even more amazing now.
Member Since: Posts: Comments:
Bone,
I'd contribute to it.
BTW: Rush hour nightmare
Member Since: Posts: Comments:
Sounds like they might even be able to save the plane. That would be great too.
Member Since: Posts: Comments:
Emergency services trying to gather all the passengers as they were rescued by a variety of different civilian watercraft.
Member Since: Posts: Comments:
141. medicroc 5:01 PM EST on January 15, 2009
FDNY reporting "no one seriously injured"
Think that captain deserves a week's extra vacation:)


and a raise!!!
Member Since: Posts: Comments:
FDNY reporting "no one seriously injured"
Think that captain deserves a week's extra vacation:)
Member Since: Posts: Comments:
yes conchy it was. from reports I am hearing within a few mintues everyone was off and was safe. I would imagine EMS treating for hypotherma the most.
Member Since: Posts: Comments:
Quoting Bonedog:
yea conchy this basically out my front door at work
Amazing and impressive how quickly they worked to get everyone off the plane safely and appears no major injuries.
Member Since: Posts: Comments:
Update on passenger count 148(dot including crew). Appears all made it off
Member Since: Posts: Comments:
yea conchy this basically out my front door at work
Member Since: Posts: Comments:
Quoting Bonedog:
yea Med. Harbor Pilot saying trying to make it to Weeks Marine Terminal. They have the equipment to lift this in one piece actually
Wow, Bone could you see the plane in the water.....talk about brr!
Member Since: Posts: Comments:
I will say one thing. Shows everyone how long a plane really floats. Would have no issues getting off the plane if you are not injured.

LOL guess I will pay attention more about those water landings now
Member Since: Posts: Comments:
yea Med. Harbor Pilot saying trying to make it to Weeks Marine Terminal. They have the equipment to lift this in one piece actually
Member Since: Posts: Comments:
yea med. like I said it apparently landed just north of the 39th street ferry terminal. From where I am I noticed 2 in the terminal at the time and immediatly were on scene
Member Since: Posts: Comments:
Bone
They're trying to tow it over to your side of the river right now
Member Since: Posts: Comments:
windchill is 9

with that water temp and air temp med services will be treating hypotherma victims figure 5 to 15 min before stage 1 sets in
Member Since: Posts: Comments:
tugs are staging now. Looks like McCallister and Moran

Member Since: Posts: Comments:
Apparently many of the rescues made by civilian watercraft prior to arrival of emergency services
21 degree enviornmental temp.
Member Since: Posts: Comments:
LOL all the news chanels have eyewitnesses on now. Amazing how many diffrent stories your getting.
Member Since: Posts: Comments:
21 degrees outside
Member Since: Posts: Comments:
Of 54 people that were taken to the ferry terminal only 2 have been transported to the hospital and they're condition described as "not serious" by NYFD
Member Since: Posts: Comments:
no problem auburn
Member Since: Posts: Comments:
123. auburn (Mod)
Thank you Bone!
Member Since: Posts: Comments:
med I stand corrected 32.5 degrees harbor pilot just told me
Member Since: Posts: Comments:
auburn manhattan County

right now any camera below 70th would be your best bet
Member Since: Posts: Comments:
med 38 degrees is water temp =/
Member Since: Posts: Comments:
Midtown Manhattan
Member Since: Posts: Comments:

Viewing: 169 - 119

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8Blog Index

Top of Page

About

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

Local Weather

Scattered Clouds
66 °F
Scattered Clouds