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Excerpt: "As the polar ice cap shriveled at unforeseen speed, Professor Steffen said he had changed his mind about the Arctic tipping point in past weeks. Existing predictions of an ice-free North Pole by 2050 were looking hopelessly wrong. ... 'I'm pretty certain that we have now passed the tipping point for Arctic sea ice.'"

Steadily shrinking ... Greenland experienced melting across 97% of its surface in June and July this year. (photo: Reuters)
Steadily shrinking ... Greenland experienced melting across 97% of its surface in June and July this year. (photo: Reuters)


Collapse of Arctic Sea Ice Has Reached Tipping Point

By Ben Cubby, Brisbane Times AU

24 September 12

 

s Artic sea ice hits a record low, scientific focus is turning to climate "tipping points" - a threshold that, once crossed, cannot be reversed and will create fundamental changes to other areas.

"It's a trigger that leads to more warming at a regional level but also leads to flow-on effects through other systems," Will Steffen, the chief adviser on global warming science to Australia's Climate Commission, said.

There are about 14 known "tipping elements", according to a paper published by the US Proceedings of the National Academy of Sciences.

In the case of the Arctic ice cap, less ice means less white surface to reflect heat and more dark water to soak it up. This leads to higher temperatures, which scientists say will unlock more ancient greenhouse gases frozen into ocean depths and permafrost, speeding climate change, interfering with ocean currents, rainfall patterns and weather.

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Next to the Arctic ice cap, Greenland experienced melting across 97 per cent of its surface in June and July. It is unclear what the tipping point is for the melting of the Greenland ice sheet. Melts similar to this year's seem to occur every century or so. What is known is that if temperatures keep rising as they are, the ice sheet will start to disintegrate on a massive scale some time in the second half of this century.

Tentative estimates from Australian and international studies say that another 1.5 degrees of warming would push Greenland across the threshold into irreversible melt, a process that would continue for centuries. There is enough ice in Greenland alone to raise sea levels off NSW and Victoria by four to nine metres.

Frozen methane trapped in pockets around the Arctic circle is also seen as a critical tipping element. Methane is a potent greenhouse gas, and as frozen earth thaws, more is leaking out. There are no exact measurements on the rate of leakage. Rough estimates suggest 30 to 60 billion tonnes of methane may leak by 2070.

Other potential tipping elements include monsoon patterns and the El Nino-Southern Oscillation cycle, which scientists expect will start to shift quite suddenly in response to global warming.

Changes in tree cover, especially in giant forests like the Amazon, are also expected in response to changing rainfall and more heat - and this would have the effect of amplifying global warming because fewer trees would mean less carbon dioxide was being soaked up out of the air.

As the polar ice cap shrivelled at unforeseen speed, Professor Steffen said he had changed his mind about the Arctic tipping point in past weeks. Existing predictions of an ice-free North Pole by 2050 were looking hopelessly wrong. "I would say that, certainly, it is looking like 2050 would be an outlier now - I'm pretty certain that we have now passed the tipping point for Arctic sea ice," he said.

Sea ice reached a minimum size of 3.41 million square kilometres, down from an average of 7.4 million in the 1980s, 6.8 million in the 1990s and 5.7 million last decade. Professor Steffen believes "the most radical projection is about 2016, and probably the most conservative projection is about 2030, for when it will be ice free".

The speed of events is why scientists are so worried. The only known way to stop these thresholds being crossed is to cut greenhouse emissions triggering these changes, and there are few signs of that occurring.

"This is absolutely the critical decade for action," climate expert Tim Flannery said this week.


 

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+47 # Mamazon 2012-09-24 09:35
Wake up Americans -- we are on the tipping point of extinction and our answer seems to be to fire up the SUV and keep driving past the speed limit! This is the decade we have to make the changes we need to make... And we all have to make them in our daily lives. Endless consumption of the Earth's resources is making this planet uninhabitable for humans and most other species. Do you care? Do you dare to change? Let's start by supportuing politicians who are not corporate puppets, who actually respect science and don't have some crazy religious dogma that stops them from thinking rationally. We need leaders that will lead us in a sustainable direction -- that bring all 100% of us together to face the reality of climate change.
 
 
+32 # VoiceofReason613 2012-09-24 09:53
How many wake-up calls do we need before we recognize that averting a climate catastrophe, severe food, water, and energy scarcities, and other environmental disasters must become a central focus of all life today. As president of Jewish Vegetarians of North America (JVNA), I want to stress that a major part of efforts to avert climate and other catastrophes is a major, societal shift to plant-based (vegan) diets.

Please consider:


* Accoding to a UN Food and Agriculture report, animal-based agriculture emits more greenhouse gases (in CO2 equivalents) than all the cars and other means of transportation worldwide combined, largely due to enormous amounts of methane, a very potent greenhouse gas emitted by cattle and other animals.

* At a time when food prices are skyrocketing and an estimated 20 million people are dying annually worldwide from hunger and its effects, over 70 percent of the grain produced in the United States and over 40 percent produced worldwide are fed to farmed animals.

* In an increasingly thirsty and energy-dependen t world, animal-based diets require up to 14 times as much water and 10 times as much energy as vegan (all plants) diets per person.
 
 
+13 # chrisconnolly 2012-09-24 11:26
And my county commissioners will roll their eyes in digested disbelief when this issue is raised. How long will it take all the idiots in power to bring the human race to the brink of extinction?
 
 
+1 # dovelane1 2012-09-25 17:18
Barr6 C9ommoner is reported to have said "By the time the average person figures it out, it will be too late."

It takes courage to admit that one might be wrong. Most people you mjention probably don't have the courage to admit that they might be wrong.

And that is what I ask them. What if you might be wrong? What will be the consequences if you are wrong, and I am right?

If we stop world population growth, and change GHG emissions, and I'm wrong, that's till a good thing. If we don't stop these things, and I'm right, you and I and all of us will be in a very bad place, in the very near future.

I tell people it takes more courage to admit that they might wrong than it does to hang on to the "courage of their convictions." Takes more courage to change one's mind than to stay in denial.

I tell them courage is the fleeing forward.

And when someone says you should be afraid, don't trust them. I become more concerned and curious about why anyone would want me to be afraid of anytning.
 
 
+1 # Granny Weatherwax 2012-09-26 07:46
...And then there is the factt hat as soon as whatever we might be doing seems to have an effect, the usual suspect will clamor to stop it because it worked already.

Reminds me of that republican guy who was telling me with ecologic report in hand that we should rescind the water pollution control regulations in his area because his river is very clean.
It works, therefore stop it!
 
 
+16 # happycamper690 2012-09-24 11:44
In these weeks before the election, we hear only token mention of the environment from the Democrats and only derisive attempts at humor by the Republicans (e.g., "Obama thinks rising oceans are more important than rising unemployment"). Yet, by any rational ordering of priorities, global warming trumps all others. From all I have read, I agree that this is the crucial decade. After this, the gates of hell are open to all of us. Do the Republicans think that "Rapture" will save them? Or, more likely, the Koch brothers have purchased their opinions.
 
 
+17 # Buddha 2012-09-24 12:11
The only people who care are us on the Left. People on the right have convinced themselves global warming is a myth or "part of natural cycles", and no amount of evidense will ever convince them. It is no coincidence that those are mostly the same people who are convinced the Earth is 6000 years old and Man rode Dinosaurs, and science on this be-damned.
 
 
0 # RobertMStahl 2012-09-24 13:19
a Paradigm is not a pair-o-dime. Among other items (i.e. Lindisfarne Association scientists, for one), anyone understand GUTCP's contribution to the greenhouse debacle? Anyone understand totalitarianism 's relationship to the status quo of education w/r time (i.e. Norman Dodd)?
 
 
-15 # MidwestTom 2012-09-24 14:38
Meanwhile, ice in Antarctica is growing to record levels, according to NOAA and other sources.
 
 
+6 # Pikewich 2012-09-24 18:06
Actually, the water stored in antarctic ice is a little more complex according to this source:
" A 2006 paper derived from satellite data, measures changes in the gravity of the ice mass, suggests that the total amount of ice in Antarctica has begun decreasing in the past few years.[9] Another recent study compared the ice leaving the ice sheet, by measuring the ice velocity and thickness along the coast, to the amount of snow accumulation over the continent. This found that the East Antarctic Ice Sheet was in balance but the West Antarctic Ice Sheet was losing mass."
 
 
+12 # Pikewich 2012-09-24 18:09
Too late for wake up calls. By the time we reach a critical mass of the "awakened", and it becomes clear to us one way or the other, the process will be well under way and very likely irreversible. Then we deal with it or we don't.
 
 
0 # RobertMStahl 2012-09-25 10:20
The minute Greenland ice crack to pieces, well before 2050, that won't be an issue anymore. The Paleocene-Eocen e maximum is a genuine concern. However, so is the formation of dimethylsulfide used in cloud formation, and, with the oceans in the northern hemisphere (where the large part of the pollution is released) 3 degrees F warmer there is a record breaking large bloom of phytoplankton that produces DMS used for global cooling. When it became part of the planet's modulation apparatus for prevent water from freezing or boiling in the universe, at large, before it became a food source, the whole planet's surface turned to ice, once. But, nothing is brought to bear on evidence in general for this very difficult issue, or with justice in general, like the evidence that exists at www.RememberBuilding7.org. Where is Indira Singh? Who is William Binney? What would it take to understand history and replace the Old Guard with a commonwealth?
 
 
-1 # Granny Weatherwax 2012-09-26 07:48
BS tends to release methane. Please abstain.
 
 
+4 # brux 2012-09-24 17:20
It is way too late to wake up ... there is so much unprocessed CO2 and environmental insults that have yet to be healed it's just silly to not think ahead.

Scientist have said the stage is set for a global die-off.

If you read Jared Diamond's books "The Third Chimpanzee" and "Collapse" we humans have done this over and over through history - destroy our environment, then regroup when possible and move on to destroy a different bigger environment. We have sacrified our own lives to do it from the moment we started to become farmers and break open the land.

The fossil record shows smaller more sickly human beings in farming cultures as opposed to hunter-gatherer s because people did not get the nutrients they needed to exist and prosper when they have to fullfill the role of machines in some military hierarchy to keep the whole thing going and expanding.

The defect in humans have been with us for a long long time to the point where we don't even see it, think about it, nor can we even accept such a massive problem with no good solutions - yet ?
 
 
+8 # RODNOX 2012-09-24 18:53
seeing as our military is by far the largest unregulated polluter and user of fossil fuels on the planet there is a great place to start.......... .
 
 
+3 # dovelane1 2012-09-25 17:32
It's been written that those you would control, you must first make afraid. The Republicans are doing their best to make people afraid.

The people buying their message want to be afraid, so they have someone else to blame for their problems. In order to stay in denial, it is a prerequisite that an enotional victim have someone else to blame for their fear.

The key is to be aware and concerned, but to never fear. Once a person gives in to fear, the Republicans, and anyone else that wants to control people, to keep them ignorant, barefoot and pregnant, or disenfranchised in any way, they have won.

We all need to stand up, and speak truth to power. The more we, the ordinary people, continue to do so, the more it empowers other ordinary people to do the same.

As Thomas Friedman wrote, "We don't need better government - we need better citizens." Anyone who reads this has to become a better citizen. Better to light a single candle to stand alone and curse the dark. Light one candle, and it encourages others to light other candles.

Protect your candle so those who fear can't put it out, and it encourages others to protect their own candles as well.
 

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