What were you doing in the summer of 2007? In mid-July, I was speaking at the AR2007 conference in Los Angeles (www.ARConference.org), and I even participated in a plenary on global warming and human population. Then, I spent the next 4 months driving through 30 states working intensely on the deer hunting, bowhunting, urban deer culling and deer immunocontraception issues, as well as forming the Global Wildlife Alliance with member groups in about as many states. But due to my laser-like concentration on the deer and hunting issues, something of enormous global importance slipped right beneath my radar, even though there were newspaper articles and newscasts galore on the subject, and perhaps it did yours too.
I’m talking about the massively record-breaking melting of the Arctic sea ice as well as the Greenland ice sheet.
Now, it is February 2008, and what happened in the summer of 2007 is history. But it is not over, because the summer of 2008 may take it yet to a new height, and no scientist in the world, except those still incredibly in denial, would dare to dismiss the possibility, or even lower its probability.
I have since amassed hundreds of articles on the subject, about 150 of which I present below for your interest. The best way I would suggest that you approach this vast amount of reading is to not to read them, at least not to begin with, but to just read their titles from beginning (1995) to end (2008). There is nothing sacred about 1995; it just happens to be the year of the first article I’ve included in this list. There is nothing particularly sacred about now either; it just happens to be the time of this writing. There were many relevant articles before 1995 and surely there will be amazing occurrences in the articles to come, especially those publishing in the summer of 2008.
You will notice that the tone of the titles of the earlier articles are more or less tentative, but as time rolled on, from year to year, it became more and more tangible, then definite, then seriously concerned, then surprised, then amazed, then unnerved, then shocked, then stunned, then horrified… Also, you will notice that the estimate of the remaining life-span of the Arctic ice cap and the Greenland icesheet was shortened from -50% by 2040 to a complete meltdown by 2013 the closer the estimators approached the summer of 2007.
Of course, for every alarm sounded, there would be the skeptics who would call the alarm sounder an “alarmist”. I have included one such debunking article dated January 28, 2007. Obviously what happened in the summer of 2007 totally exonerated the “alarmist” and demolished the debunker. Still, even after the great plunge of 2007, the skeptics and cynics are again mouthing that it was nothing but an “anomaly”, and that the ice was reforming. Well, one of the reasons is called “winter”. And the summer of 2008 will likely silence them again.
A general consensus amongst the articles was that the 2007 Arctic meltdown exceeded expectations by three fold. Indeed, the titles below contain phases as “stunned experts” and “shocked scientists”. And what was expected was already quite dire.
This is a direct revelation from nature not to be slighted, much less ignored. The same computer models that underestimated the 2007 Arctic ice melting rate are the same models that estimated only 2-4 degree increases in the global temperature by 2100, and a moderate 30% extinction rate. These same models also underestimated the role in global warming of the greenhouse gas called methane.
Methane as a greenhouse gas (GHG) is 20 times more potent than carbon dioxide. The Arctic permafrost contains an immense quantity of methane stored in the solid form of methane clathrate. If the permafrost is melted, the atmospheric GHG would increase by 50%. The current atmospheric GHG concentration is 370 ppm. Scientists say that the maximum should be capped at 400 ppm to prevent “tipping” the system into a runaway greenhouse effect. A 50% GHG concentration rise means 550ppm, deep in the danger zone if not past the point of no return. And we haven’t even considered the methane stored in clathrate form on and under the continental shelves around the world.
If methane is release as free gas into the atmosphere, it will raise the global temperature even higher, which will melt even more permafrost which will release more methane… a positive feedback loop that could push the global temperature spirally out of control. And this is only one of several positive feedback loops.
Another is the albedo feedback loop, where less ice reflects less solar heat, causing more heat absorption, temperature increases and ice melting.
In the context of global warming, there is such a thing as “tipping points”. And nine “tipping elements” have been identified in which tipping points exist. I believe that no matter what field and discipline we specialize in, we should all know something about global warming, because it involves all life on Earth and for all time. The 9 tipping elements and their possible timeframes are:
1) Melting of Arctic sea-ice (approx 10+ years, small uncertainty). As sea-ice melts, it exposes a much darker ocean surface, which absorbs more radiation than white sea-ice so that the warming is amplified. This causes more rapid melting in summer and decreases ice formation in winter. Over the last 16 years ice cover during summer declined markedly. The critical threshold global mean warming may be between 0.5 to 2 degrees Celsius, but could already have been passed. One model shows a nonlinear transition to a potential new stable state with no arctic sea-ice during summer within a few decades.
2) Decay of the Greenland ice sheet (more than 300 years, small uncertainty). Warming over the ice sheet accelerates ice loss from outlet glaciers and lowers ice altitude at the periphery, which further increases surface temperature and ablation. The exact tipping point for disintegration of the ice sheet is unknown, since current models cannot capture the observed dynamic deglaciation processes accurately. But in a worst case scenario local warming of more than three degrees Celsius could cause the ice sheet to disappear within 300 years. This would result in a rise of sea level of up to seven meters.
3) Collapse of the West Antarctic ice sheet (more than 300 years, large uncertainty). Recent gravity measurements suggest that the ice sheet is losing mass. Since most of the ice sheet is grounded below sea level the intrusion of ocean water could destabilize it. The tipping point could be reached with a local warming of five to eight degrees Celsius in summer. A worst case scenario shows the ice sheet could collapse within 300 years, possibly raising sea level by as much as five meters.
4) Collapse of the Atlantic thermohaline circulation (approx 100 years, intermediate uncertainty). The circulation of sea currents in the Atlantic Ocean is driven by seawater that flows to the North Atlantic, cools and sinks at high latitudes. If the inflow of freshwater increases, e.g. from rivers or melting glaciers, or the seawater is warmed, its density would decrease. A global mean warming of three to five degrees Celsius could push the element past the tipping point so that deep water formation stops. Under these conditions the North Atlantic current would be disrupted, sea level in the North Atlantic region would rise and the tropical rain belt would be shifted.
5) Increase in the El Niño Southern Oscillation (approx 100 years, large uncertainty). The variability of this ocean-atmosphere mode is controlled by the layering of water of different temperatures in the Pacific Ocean and the temperature gradient across the equator. During the globally three degrees Celsius warmer early Pliocene ENSO may have been suppressed in favor of persistent El Niño or La Niña conditions. In response to a warmer stabilized climate, the most realistic models simulate increased El Niño amplitude with no clear change in frequency.
6) Collapse of the Indian summer monsoon (approx 1+ year, large uncertainty). The monsoon circulation is driven by a land-to-ocean pressure gradient. Greenhouse warming tends to strengthen the monsoon since warmer air can carry more water. Air pollution and land-use that increases the reflection of sunlight tend to weaken it. The Indian summer monsoon could become erratic and in the worst case start to chaotically change between an active and a weak phase within a few years.
7) Greening of the Sahara/Sahel and disruption of the West African monsoon (approx 10 years, large uncertainty). The amount of rainfall is closely related to vegetation climate feedback and sea surface temperatures of the Atlantic Ocean. Greenhouse gas forcing is expected to increase Sahel rainfall. But a global mean warming of three to five degrees Celsius could cause a collapse of the West African monsoon. This could lead either to drying of the Sahel or to wetting due to increased inflow from the West. A third scenario shows a possible doubling of anomalously dry years by the end of the century.
8) Dieback of the Amazon rainforest (approx 50 years, large uncertainty). Global warming and deforestation will probably reduce rainfall in the region by up to 30 percent. Lengthening of the dry season, and increases in summer temperatures would make it difficult for the forest to re-establish. Models project dieback of the Amazon rainforest to occur under three to four degrees Celsius global warming within fifty years. Even land-use change alone could potentially bring forest cover to a critical threshold.
9) Dieback of the Boreal Forest (approx 50 years, large uncertainty). The northern forests exhibit a complex interplay between tree physiology, permafrost and fire. A global mean warming of three to five degrees Celsius could lead to large-scale dieback of the boreal forests within 50 years. Under climate change the trees would be exposed to increasing water stress and peak summer heat and would be more vulnerable to diseases. Temperate tree species will remain excluded due to frost damage in still very cold winters.
Bear in mind that all of these estimate are uncertain, and some if not all could be gross underestimates. I refer to the time frame as well as the severity. No matter when it comes, a 6 degree global temperature rise is the tipping point of survivability of most life on Earth, and will doom the present-day Earth to the 6th mass extinction (already well in progress). The 3rd mass extinction, the End-Permian 251 million years ago, wiped out 75% of all land species and 95% of all marine species. The agent was indeed global warming.
This is not to say that the world is doomed. It is to say that if we carry on the way we have, which has channeled us into the current predicament to begin with, we would doom all life on Earth, the Earth itself, and us ourselves.
Arctic sea-ice and the Greenland ice sheet are regarded as the most sensitive tipping elements with the smallest uncertainty. Here are the sample articles that will give you a stunning vision of these two tipping elements in no uncertain terms:
1995-03-24 NERSC - The sea ice in the Arctic is melting, is this a sign of global warming?
1997 Greenpeace - Climate Change and Arctic Sea Ice
1998 The Arctic: the ocean, sea ice, icebergs, and climate
1999 UNEP – Thinning of Arctic sea ice
1999-04-20 USGCRP - Arctic sea ice: changes, causes, and implications
2000-05-25 The Arctic sea ice is melting- How long will it last?
2000-12-01 BBC News – Arctic sea ice “thins by almost half”
2001-12 Alaska Sea Ice Atlas
2001-12-03 Arcus.org – Implications of changes in Arctic sea ice
2003 NOAA - What changes have occurred in Arctic sea ice volume and dynamics over the past 50 years?
2003-01-01 NOAA - How does Arctic sea ice form and decay?
2003-05-07 NASA - Greenland ice melting
2003-10-24 Earth Observatory - Dwindling Arctic ice
2003-12-01 Space Daily - Shrinking Arctic tells many stories
2004-04-08 National Geographic News - Greenland melt may swamp LA and other coastal cities
2004-07-28 BBC News – Greenland ice melt “speeding up”
2005-06-29 NOAA Ocean Explorer – Arctic sea ice
2005-07 NASA - Record low for June Arctic sea ice
2005-07-11 NOAA Ocean Explorer – Arctic sea ice, channels of life
2005-09-21 Bloomberg.com - Arctic Sea Ice Shrinks to Record Low, Scientists Say
2005-09-21 Washington Post – Melting Arctic sea ice
2005-09-28 CTV – Global warming causing record Arctic ice melt
2005-09-28 NASA - Arctic sea ice continues to decline, Arctic temperatures continue to rise in 2005
2005-09-28 Sea ice decline intensifies – Summer Arctic sea ice falls far below average for fourth year, winter ice sees sharp decline, spring melt starts earlier.
2005-09-28 Softpedia - The Arctic sea ice is melting rapidly
2005-09-28 Steffen Research Group - Greenland melting
2005-09-29 Alaska.com – Arctic ice meltdown continues rapid pace
2005-09-29 New Scientist - Melting of sea ice speeds up in Arctic
2005-09-30 The Herald, NZ – Arctic sea ice melts to all time low
2005-09-29 The Register – Arctic sea ice gone within a century?
2005-12-18 TIMES - Polar bears drown as ice shelf melts
2006-02-16 MSNBC – Greenland’s glaciers losing ice at faster rate
2006-03 14 The Independent - Arctic sea ice fails to re-form
2006-08-07 CU News – Record retreat of Arctic sea ice
2006-08-11 BBC News - Greenland ice melt faster than in 2004 – satellite measurements show
2006-08-11 Washington Post - Greenland’s melting ice sheet speeding up
2006-09-06 ABC News - An ice-free Arctic… happening before our eyes
2006-09-13 NASA – NASA sees rapid changes in Arctic sea ice
2006-09-15 Associated Press - 2 NASA studies report faster Arctic sea ice melt
2006-09-14 Rocky Mountain News - Scientists: Arctic sea ice tells of warming - Wintertime declines seen as strong sign of climate change
2006-09-14 IOL – Concern as Arctic sea ice shrinks
2006-09-14 Vive le Canada – Arctic ice melts in winter
2006-10-03 University of Colorado - Arctic sea ice declines again in 2006, say University of Colorado researchers
2006-10-04 ENS - Arctic sea ice melt accelerating
2006-10-04 Earth Times - Arctic Ocean losing more sea ice every year, scientists warn
2006-10-04 Globe & Mail - Arctic sea ice at all time low, researcher says
2006-10-04 Mongabay.com - Arctic sea ice levels fall
2006-10-05 Al Jazeera English – “Global Warming” shrinks Arctic sea ice
2006-11-20 NOAA – New date show downward trend in Arctic sea ice
2006-12-11 UCAR - Abrupt Ice Retreat Could Produce Ice-Free Arctic Summers by 2040
2006-12-12 Arctic sea ice 'faces rapid melt' - The Arctic may be close to a tipping point that sees all-year-round ice disappear very rapidly in the next few decades, US scientists have warned.
2007-01 Geophysical Fluid Dynamics Laboratory – Arctic sea ice changes in GFDL climate scenario experiments
2007-01-08 World Resources Institute - Melting Arctic sea ice threatens polar bears
2007-01-12 RealClimate – Arctic sea ice declines in the 21st Century + 127 responses
x2007-01-18 World Climate Report - Arctic forecast: Nordic sea ice expansion (proven wrong by what happened later same year, and the “alarmists” right.)
2007-03-15 Science Daily - Arctic sea ice decline may trigger climate change cascade
2007-03-16 The Guardian - Arctic ocean may lose all its ice by 2040, disrupting global weather
2007-03-16 Science - Perspectives on the Arctic's Shrinking Sea-Ice Cover
2007-03-16 The Independent - Collapse of Arctic sea ice 'has reached tipping-point'
2007-04-03 CBC News - Arctic sea ice vanishing: NASA
2007-04-30 MSNBC - Arctic sea ice melting much faster, experts find - Study indicates that U.N. reports on warming are too conservative
2007-04-30 USA Today – Arctic sea ice is melting 3 times faster than projected
2007-05-01 Herald Tribune - Arctic ice is melting faster, report says
2007-05-01 New York Times - Arctic sea ice melting faster, a study finds
2007-05-07 ePluribus Media - Arctic sea ice: going, going, gone.
2007-05-07 Scitizen - A Condensed Look at “Arctic sea Ice Decline: Faster Than Forecast?” - A new study indicates that the Arctic Ocean is losing its sea ice cover faster than is captured by the most advanced models used in the 2007 report by the Intergovernmental Panel on Climate Change (IPCC).
2007-05-28 VOA News - Report says Arctic sea ice melting more quickly than thought
2007-06-29 ENS - Arctic sea ice extent hits record low
x2007-07-27 US Senate Committee - Latest Scientific Studies Refute Fears of Greenland Melt
2007-07-05 Earth Exploration Toolbook – Whither Arctic sea ice?
2007-08-10 Canwest News Service - Arctic sea ice shrinking at a record rate, says scientist
2007-08-10 RealClimate – Arctic sea ice watch
2007-08-11 ABC News - Arctic sea ice shrinks to record low
2007-08-13 Foreign Policy - Arctic sea ice melting faster than ever
2007-08-15 The Independent - Scientists warn Arctic sea ice is melting at its fastest rate since records began
2007-08-17 CommonDreams.org - Arctic sea ice shrinks to record low
2007-08-17 Discovery Channel – Arctic sea ice shrinks to new low
2007-08-17 NPR – Researchers: Arctic seas ice hits record low
2007-08-17 PlanetArk - Arctic sea ice expected to hit record low in Sept.
2007-08-20 ENS - Arctic sea ice extent hits record low
2007-08-20 National Geographic News - Arctic ice at all time low
2007-08-22 CNN - Arctic sea ice expected to hit record low (with video)
2007-09-04 The Guardian, UK - Loss of Arctic ice leaves experts stunned
2007-09-06 NOAA – Arctic regional sea ice to decline 40% before 2050
2007-09-09 Oregon Live - Greenland ice melt shocks scientists
2007-09-20 University of Colorado - Arctic sea ice bottoms out for 2007, shatters all time record low, Say CU-Boulder Scientists
2007-09-11 CNN – Arctic sea ice cover at record low
2007-09-14 Mongabay.com - Arctic sea ice thickness only half of 2001 level
2007-09-20 Arctic sea ice cover record low (map)
2007-09-21 CBC News - Melting of Arctic sea ice shatters record
2007-09-22 Telegraphy, UK - Arctic sea ice 'melts to all-time low'
2007-09-26 Fox News - Arctic sea ice shrinking, thinning even in winter
2007-09-26 Wired Science - Arctic Sea Ice Melting Faster Than Expected
2007-09-26 WSWS – Arctic sea ice reaches record minimum
2007-09-27 USGS - Future retreat of Arctic sea ice will lower polar bear populations and limit their distribution
2007-10-01 Channel 4 - Record-breaking Arctic sea ice melt
2007-10-01 Live Science - Record low Arctic sea ice confirmed
2007-10-01 Science Mode - Arctic Sea Ice Plummeted To Lowest Levels, 50% since 1950s
2007-10-02 New York Times – Arctic melt unnerves the experts
2007-10-02 Reuters, UK – Scientists see dramatic drop in Arctic sea ice
2007-10-02 United Press Intl (UPI) - Arctic sea ice shatters record low
2007-10-03 CO2 Science - Declining Arctic Sea Ice: Has a "Tipping Point" Been Passed?
2007-10-04 The Planetary Society – Record Arctic sea ice loss
2007-10-11 Climate Change – Arctic sea ice heading for rapid disintegration
2007-10-24 CNN – Greenland’s ice sheet melts as temperatures rise
2007-10-22 In The News, UK – Arctic ice reaches record low
2007-10-24 NASA – Astounding Arctic sea ice melt (video)
2007-10-29 AGU - Arctic sea ice decline: faster than forecast
2007-10-30 NASA – Astounding video: Arctic sea ice loss 1970-2007
2007-12 YouTube - Melting Arctic sea ice
2007-12-11 Seattle Times - 'The Arctic is screaming' — summer sea ice could be gone in five years
2007-12-12 C/Net - Record heat sweeps Arctic Sea, ice in 2007
2007-12-12 China View - Arctic summer sea ice may disappear in 5 years
2007-12-12 National Geographic - Arctic sea ice gone in summer within 5 years?
x2007-12-12 The Daily Green - Arctic Sea Ice Re-Freezing at Record Pace
2007-12-12 Philadelphia Enquirer - A huge drop in sea ice sparks plea: 'The Arctic is screaming'
2007-12-12 Science Daily - Greenland melt accelerating
2007-12-13 Live Science – Magma may be melting Greenland ice
2007-2008 International Polar Year (IPY) full proposal details
2007-2008 International Polar Year (IPY) – Monitoring the drift, thickness and mass balance of Arctic sea ice
2008 Arctic sea-ice monitor by AMSR-E
2008-01 MSNBC - Arctic sea ice shrinking faster, NASA finds
2008-01-01 Cryosphere Today – 1978-2007 Historic sea ice data (daily)
2008-01-01 NOAA - Northern hemisphere ice charts, GIS, metadata, and coverage files
x2008-01-10 Christian Science Monitor - As Arctic ices melts, South Pole ice grows
2008-01-10 University of Colorado - Older Arctic sea ice replaced by young, thin ice, says CU-Boulder study
2008-01-15 ENN - Greenland suffers from extreme ice melt
2008-01-18 Discovery Channel – Thick, old Arctic ice nearly gone
x2008-02-01 Heartland Institute - Arctic Sea Ice Expanding at Record Pace
2008-02-07 Protection Sought for Pacific Walrus
2008-02-07 The Cryosphere Today
2008-02-07 SOCC – Current Arctic sea ice extent
2008-02-07 Live Science – Video depicting Arctic sea ice shrinkage 1990-2049
x2008-02-08 Mother Jones - Antarctic Sea Ice Increase: Fodder for Global Warming Skeptics?
2008 daily AMSR-E - Daily updated sea ice maps