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Tipping Points: How Arctic Warming Could Chill Western Europe

By Guest Writer

Nov 12, 2009

In his new book, A World Without Ice, geophysicist Henry Pollack explains the complex influences that Earth's ice has had on human survival, and that population growth and industrialization are now having on the survival of Earth's ice. Following is an excerpt.

By Henry Pollack

Just as the international financial system surprised the world with a major collapse in 2008, the global climate system, with its human component, is equally capable of serious surprises.

Lurking in the shadows of climate change is the possibility that the accelerations we now observe in the climate system are portends of approaching tipping points.

Tipping points represent changes in the a system that occur when the system passes form one mode of behavior to another, sometimes imperctibly, sometimes suddenly. A simple analogy is the process of paying off a home mortgage.

Each monthly mortgage payment comprises both interest and principal. In the early years of the mortgage, the payoff of the loan principal is painfully slow and annoyingly incremental, as most of the monthly payment goes to paying the interest on the loan.

In a typical 30-year home mortgage, a homeowner, after 10 years of payments, has paid off only 10 percent of the loan. After 21 years of payments, the monthly check is finally split evenly between interest and principal, a tipping point that typically passes without recognition or acknowledgment. But beyond that tipping point, the reduction of the unpaid balance accelerates, and, as the mortgage approaches payoff, there is a rapid erosion of the remaining unpaid loan. At the end, there is another tipping point, impossible not to notice — a very abrupt transition to a new state in the homeowners’ personal finances, when there is no mortgage payment to make at all.

In the climate system, there are several possible tipping points: major realignments of oceanic and atmospheric circulation, rapid releases of greenhouse gases now trapped in permafrost and in the ice that exists at shallow depths beneath the ocean floor, and sudden changes in sea level. All these possibilities are related to changes in Earth’s ice.

What role does ice have in taking the climate across a tipping point?

The average temperature of a planet’s surface depends directly on the amount of incoming solar energy absorbed by the surface. But not all the solar radiation delivered to Earth is absorbed — some is reflected back into space.

Snow and ice are both highly reflective substances, and so the fraction of Earth’s surface covered by snow and ice is a big determinant of Earth’s average surface temperatures. The more radiation that is reflected away, the less energy remains to warm the planet. Currently, Earth reflects about 30 percent of the arriving solar radiation back into space.

When the amount of snow and ice cover changes over time, so does the balance between reflection and absorption of solar energy. As ice increases on Earth, more solar energy is returned to space and less is absorbed, thus lowering the surface temperature. More ice promotes a cooler planet, and a cooler planet encourages the accumulation of even more ice. This interaction is called a positive feedback, and leads to an ever-faster acceleration of climate change.

Diminishing ice cover also drives a similar feedback, but in the other direction: As Earth becomes darker and less reflective, more solar radiation is absorbed, and the planetary surface grows warmer, and a warmer planet leads to even less ice cover and a further acceleration in warming.

How do the ice-climate feedbacks lead to tipping points in the climate?

National Security Implications of Global Warming/ Abrupt Climate

Informative article. I gave the following power-point presentation at the Veterans for Peace National Convention in Seattle, Washington, August 2006: A WORLD OF HURT OR HOPE – The National Security Implications of Global Warming/ Abrupt Climate Change

FYI: Mini ice age took hold


Mini ice age took hold of Europe in months
11 November 2009 by Kate Ravilious

JUST months - that's how long it took for Europe to be engulfed by an ice age. The scenario, which comes straight out of Hollywood blockbuster The Day After Tomorrow, was revealed by the most precise record of the climate from palaeohistory ever generated.

Around 12,800 years ago the northern hemisphere was hit by the Younger Dryas mini ice age, or "Big Freeze". It was triggered by the slowdown of the Gulf Stream, led to the decline of the Clovis culture in North America, and lasted around 1300 years.

Until now, it was thought that the mini ice age took a decade or so to take hold, on the evidence provided by Greenland ice cores. Not so, say William Patterson of the University of Saskatchewan in Saskatoon, Canada, and his colleagues.


North Carolina Sea Levels Rising Three Times Faster Than In Previous 500 Years, Study Finds

ScienceDaily (Oct. 29, 2009) - An international team of environmental scientists led by the University of Pennsylvania has shown that sea-level rise, at least in North Carolina, is accelerating. Researchers found 20th-century sea-level rise to be three times higher than the rate of sea-level rise during the last 500 years. In addition, this jump appears to occur between 1879 and 1915, a time of industrial change that may provide a direct link to human-induced climate change.

Sea Levels Rose Two Feet

Sea Levels Rose Two Feet This Summer in U.S. East
Brian Handwerk
for National Geographic News
September 10, 2009

“Now a new report has identified the two major factors behind the high sea levels—a weakened Gulf Stream and steady winds from the northeastern Atlantic.”


Strange Phenomena
By HANK ROWLAND The Brunswick News

“That's NOAA's conclusion for higher-than-usual sea levels recorded in June and July. An analysis of data it collected points to persistent winds and a weakened current in the Mid-Atlantic as the likely culprits, it said.”

EDUCATIONAL VIEWING: Gulf Stream and the Next Ice Age (2007)

EDUCATIONAL VIEWING: Gulf Stream and the Next Ice Age (2007)

“The possibility of an Ice Age in Europe prefaces this thought-provoking documentary about the rising concerns of global warming and its effects on Earth’s ecosystems and the flow of the Gulf Stream.
Filmmakers Nicolas Koutsikas and Stephan Poulle demonstrate how the disruption of ocean currents – the natural circulation of water known as the Gulf Stream – will provoke unstoppable changes that will result in the next ice age.
Thoroughly researched and engrossing, Gulf Stream and the Next Ice Age offers a profound insight into mankind’s influence on climate change through the eyes of some of the brightest scientific minds of our time.”

Big Freeze Plunged Europe Into Ice Age in Months

Big Freeze Plunged Europe Into Ice Age in Months

ScienceDaily (Nov. 30, 2009) — In the film The Day After Tomorrow, the world enters the icy grip of a new glacial period within the space of just a few weeks. Now new research shows that this scenario may not be so far from the truth after all.

Copenhagen: The era of climate stability is coming to an end

Copenhagen: The era of climate stability is coming to an end
After 400 generations of stable weather, the world is on the brink of violent climate change. But there is good news too
Fred Pearce
The Guardian, Monday 30 November 2009

For about 10,000 years, our climate on Earth has been stable. Remarkably stable, in fact. Since the end of the last ice age, we humans have spent 400 generations taking advantage of this stability to build our civilisation.

An abrupt wind shift in western Europe at the onset of ...

LOOKING BACK: An abrupt wind shift in western Europe at the onset of the Younger Dryas cold period
Nature Geoscience 1, 520 - 523 (2008) 
Published online: 1 August 2008 | doi:10.1038/ngeo263

The Younger Dryas cooling 12,700 years ago is one of the most abrupt climate changes observed in Northern Hemisphere palaeoclimate records1, 2, 3, 4. Annually laminated lake sediments are ideally suited to record the dynamics of such abrupt changes, as the seasonal deposition responds immediately to climate, and the varve counts provide an accurate estimate of the timing of the change. Here, we present sub-annual records of varve microfacies and geochemistry from Lake Meerfelder Maar in western Germany, providing one of the best dated records of this climate transition5. Our data indicate an abrupt increase in storminess during the autumn to spring seasons, occurring from one year to the next at 12,679 yr BP, broadly coincident with other changes in this region. We suggest that this shift in wind strength represents an abrupt change in the North Atlantic westerlies towards a stronger and more zonal jet. Changes in meridional overturning circulation alone cannot fully explain the changes in European climate6, 7; we suggest the observed wind shift provides the mechanism for the strong temporal link between North Atlantic Ocean overturning circulation and European climate during deglaciation.

Absence of evidence for a meteorite impact event 13,000 years ag

Absence of evidence for a meteorite impact event 13,000 years ago
as a trigger for the Younger Dryas abrupt cooling and the Megafauna extinction
University of Hawaiʻi at Mānoa
Posted: Dec. 7, 2009

An international team of scientists led by researchers at the University of Hawaiʻi at Mānoa have found no evidence supporting an extraterrestrial impact event at the onset of the Younger Dryas ~13,000 years ago.

A changing climate: UNEP maps extreme weather events worldwide

A changing climate: UNEP maps extreme weather events worldwide
Posted by Felicity Carus
Tuesday 8 December 2009 17.51 GMT

In the run-up to Copenhagen, the United Nations Environment Programme (UNEP) published its Climate Change Science Compendium, a summary of 400 peer-reviewed research papers published since 2006.

Will Essential Ocean Currents Be Altered by Climate Change?

In Deep Water: Will Essential Ocean Currents Be Altered by Climate Change? [Slide Show]
Scientists are struggling to get a grasp on the huge volumes of water flowing through the world's oceans
By Nancy Bazilchuk
December 10, 2009

Every second, a vast quantity of cold, dense seawater equal to six times the combined flow of every land river on Earth streams over an ocean-floor ridge that stretches between Greenland and Scotland. This deep southbound current, flowing from the Norwegian, Iceland and Greenland seas into the North Atlantic, is the lower limb of the Gulf Stream and its northerly extension, a great conveyor belt of ocean heat and salt that transports warm tropical water north from the equator. Most climate change models predict global warming will slow these flows, in part by altering a key component of the Atlantic's circulation, called deep-water formation. If that happens, northern Europe will cool—or warm less severely—as the rest of the globe swelters.

Understanding Ocean Climate

Understanding Ocean Climate

ScienceDaily (Dec. 10, 2009) — High-resolution computer simulations performed by scientists at the National Oceanography Centre, Southampton (NOCS) are helping to understand the inflow of North Atlantic water to the Arctic Ocean and how this influences ocean climate.

New Discoveries Could Improve Climate Projections

New Discoveries Could Improve Climate Projections

ScienceDaily (Dec. 11, 2009) — New discoveries about the deep ocean's temperature variability and circulation system could help improve projections of future climate conditions.


LOOKING BACK: Has An Ocean Circulation Collapse Been Triggered?

ScienceDaily (Feb. 25, 2008) — Predictions that the 21st century is safe from major circulation changes in the North Atlantic Ocean may not be as comforting as they seem, according to a Penn State researcher.

Submersible is first robot to cross ocean

Submersible is first robot to cross ocean
By DAVID BROWN The Washington Post
Article published Dec 17, 2009

She was at sea for 221 days. She was alone, often in dangerous places, and usually out of touch. Her predecessor had disappeared on a similar trip, probably killed by a shark. Yet she was always able to do what was asked, to head in a different direction on a moment's notice and report back without complaint.

So is it any surprise tears were shed when people could finally wrap their arms around her steel torso once more?

"She was a hero," said Rutgers University oceanographer Scott Glenn last week after retrieving an aquatic glider called the Scarlet Knight from the stormy Atlantic off western Spain. The 7-foot-9-inch submersible device, shaped like a large-winged torpedo, had just become the first robot to cross an ocean.

...How Stable Is the Contemporary Environment?

Tipping Elements in the Earth System: How Stable Is the Contemporary Environment?

ScienceDaily (Jan. 6, 2010) — A Special Feature of the Proceedings of the National Academy of Sciences presents the latest scientific insights on so-called tipping elements in the planetary environment. These elements have been identified as the most vulnerable large-scale components of the Earth System that may be profoundly altered by human interference. If one or more of those components is tipped -- especially in the course of global warming -- then the age of remarkably stable environmental conditions on Earth throughout the Holocene may end quickly and irreversibly.

Villain of the winter's tale lies in Greenland

Villain of the winter's tale lies in Greenland
Published Date: 07 January 2010
By Stephen McGinty

IT MIGHT be referred to as "upside-down weather". In Scotland, temperatures are well below the seasonal norm. Yet in Canada it is positively balmy, with Goose Bay in Newfoundland barely getting below zero, whereas the average minimum for January is -23C.

The unpredictable darkness

The unpredictable darkness, Thursday 7 January 2010 09.30 GMT

I fear the predictable unpredictable. Over the past decade there have been many warnings about Global Warming; precise extrapolations of temperature increases and projections of sea level rise. Such prognostication is understandable, they make the threat concrete to a complacent public. But the reality is that these physical processes are non-linear systems subject to wild fluctuations, with "flips" between alternative equilibrium states. Try to turn that into punchy prose!


Where on Earth is it unusually warm? Greenland and the Arctic Ocean, which is full of rotten ice
by Joseph Romm on 01/06/2010 16:22

It’s cold here and in northern Eurasia, but it’s been positively toasty ar0und the Arctic circle — thanks to an extreme negative phase of the Arctic Oscillation, as the National Snow and Ice Data Center (NSIDC) explained in their online report yesterday.

Very Strong, Negative Arctic Oscillation having Widespread Impac

Very Strong, Negative Arctic Oscillation having Widespread Impact
Brett Anderson
JANUARY 7, 2010

An extreme, negative phase of the Arctic Oscillation (-AO) during the month of December has helped keep the overall sea ice extent in the Arctic during the month of December well below the 1979-2000 average, as temperatures over the Arctic Ocean were well above-normal during the month, according to the National Snow and Ice Data Center (NSIDC) update.

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