Daily Archives: October 17, 2015

Deep concerns as climate impacts on Gulf Stream flow

March 25, 2015, by Tim Radford

Meltwater on the Greenland ice sheet could affect currents as it enters the sea.
Image: James Balog/Aurora Photos via Flickr

Ocean scientists find evidence of an increasing slowdown in the Atlantic’s “invisible river” that could seriously affect weather and sea levels in the US and Europe. LONDON, 25 March, 2015 − Climate scientists have once again confirmed an alarming slowdown in the circulation of the Atlantic Ocean − the process that drives the current that warms Europe, and powers the planetary climate. And this time, they are prepared to say that the changes are recent − and may be linked to global warming. The Atlantic Conveyor is a great invisible river that flows in two directions at the same time. The equatorial surface waters − warm, and therefore less dense − flow towards the north in the form of the Gulf Stream. Around Greenland, the denser and colder Arctic waters sink to the ocean bottom and begin their progress towards the south. It is the difference in temperatures that maintains the turnover and keeps the climate engine going. As a consequence, the two-way traffic of warm and cold water redistributes heat around the planet and keeps Britain and maritime Europe in relatively mild conditions. But as global average temperatures rise, and the Greenland ice sheet melts, ocean scientists have warned that the speed of the ocean turnover could be put at risk.

Greater weakening

Stefan Rahmstorf, an ocean physicist at the Potsdam Institute for Climate Impact Research in Germany, is lead author of a report in Nature Climate Change that says they now have evidence of a slowdown during the 20th century, and greater weakening since the first alarms 40 years ago about the possible effects of greenhouse emissions. “It is conspicuous that one specific area in the North Atlantic has been cooling in the past hundred years, while the rest of the world heats up,” Professor Rahmstorf says. “Now we have detected strong evidence that the global conveyor has indeed been weakening in the past hundred years, particularly since 1970.” The paradox of the Atlantic current is that, in a warmer world, it could slow down or halt, which would deliver uncomfortable consequences for maritime Europe. Fears of such an effect provided the scenario for the 2004 climate disaster movie, The Day After Tomorrow, which predicated a frozen Britain and a glaciated US.

“Now we have detected strong evidence that the global conveyor has indeed been weakening in the past hundred years, particularly since 1970”

No such extreme outcome was ever likely, but the Gulf Stream certainly makes a big difference to Britain. A former UK chief scientist once calculated that it delivered 27,000 times the warmth that Britain’s power stations could supply and, as a consequence, the UK is on average 5°C warmer than it might be, given its latitude.

…(read more).

Global Climate Change
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Abrupt changes in the southern extent of North Atlantic Deep Water during Dansgaard-Oeschger events

The glacial climate system transitioned rapidly between cold (stadial) and warm (interstadial) conditions in the Northern Hemisphere1. This variability, referred to as Dansgaard–Oeschger variability2, is widely believed to arise from perturbations of the Atlantic Meridional Overturning Circulation3, 4, 5. Evidence for such changes during the longer Heinrich stadials has been identified, but direct evidence for overturning circulation changes during Dansgaard–Oeschger events has proven elusive6. Here we reconstruct bottom water [CO32−] variability from B/Ca ratios of benthic foraminifera and indicators of sedimentary dissolution, and use these reconstructions to infer the flow of northern-sourced deep water to the deep central sub-Antarctic Atlantic Ocean. We find that nearly every Dansgaard–Oeschger interstadial is accompanied by a rapid incursion of North Atlantic Deep Water into the deep South Atlantic. Based on these results and transient climate model simulations7, we conclude that North Atlantic stadial–interstadial climate variability was associated with significant Atlantic overturning circulation changes that were rapidly transmitted across the Atlantic. However, by demonstrating the persistent role of Atlantic overturning circulation changes in past abrupt climate variability, our reconstructions of carbonate chemistry further indicate that the carbon cycle response to abrupt climate change was not a simple function of North Atlantic overturning.

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‘The Day After Tomorrow’ Ice Age Scenario Could Be Possible, Researchers Say

Tim Radford, Climate News Network | October 16, 2015 12:38 pm
Two separate and very different studies have confirmed a climate paradox—that global warming and a slowdown in the Atlantic Ocean currents could trigger climate change and bring a prolonged chill in Europe.

Icicles glisten as the sun sets in Denmark. Photo credit: Teralaser / Flickr

One researcher argues that not only could it happen, it must have happened every 1,500 years or so during the last Ice Age and that the transitions were complete within one to two centuries.

Another scientist has used the latest climate model to test what would happen if the Atlantic current slowed or collapsed during a period of global warming. He found that for 20 years the planet would cool, rather than continue to warm. And then global warming would resume.

Julia Gottschalk, an Earth scientist at Cambridge University and her colleagues report in Nature Geoscience that they examined links between ocean circulation and alternating cold and warm periods that ended 12,000 years ago—long before human civilization began to increase the carbon dioxide content in the atmosphere and trigger global warming.

Climate Machine

The ocean phenomenon in question is known to climate scientists as the Atlantic Meridional Overturning Circulation (AMOC). The Gulf Stream that delivers surface tropic warmth to the North Sea and Scandinavia is part of this global climate machine, also sometimes referred to as the Atlantic Conveyor because it returns cold dense water along the ocean bottom towards the Equator and the Southern Ocean.

By looking at evidence from fossilized plankton and from ice cores, the Cambridge team pieced together a story of alternating Ice Age climate change independent of humans. As sea surfaces got warmer, icebergs broke off the Northern hemisphere ice sheets and large amounts of fresh water entered the oceans.

…(read more).

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Obama Cancels Arctic Drilling Leases

Kayaktivists protest Arctic drilling in Seattle, Washington. Photo credit: Natural Resources Defense Council

Niel Lawrence | October 17, 2015 10:27 am |
It just keeps getting better and better for the Arctic. First, Shell Oil pulled the plug on its horrific current drilling effort there two weeks ago.

Now the Obama administration has taken its first concrete steps to reduce future threats. Yesterday, it cancelled new lease sales scheduled for next year and 2017 in our Polar Bear Seas—the Chukchi and Beaufort—off the north Alaskan coast. And just said “No” to extension requests from Shell and others holding existing leases in the region.

This is big. Up to now, the federal government has treated Arctic Ocean drilling as a done deal. As recently as last May, the President tweeted: “we can’t prevent oil exploration completely in region.”

His administration focused on excluding some high value areas and saying drilling would be subject to high standards. It tentatively proposed to allow more leasing in the Arctic Ocean (and the Atlantic) after 2017.

But the tide has changed. Shell made a spectacle of itself, rushing to drill. Mother Nature asserted herself. Human error propagated in the harsh conditions.

Kayaktivists spotlighted Arctic drilling as a climate issue—rightly, because huge new investments in dirty fuels can’t be harmonized with accelerating the shift to a clean energy future.

Shareholders demanded that Shell explain how its exploration policies squared with limiting damage from global warming. Again rightly, not least because of the likelihood that increasingly effective carbon regulation and affordable efficiency and clean fuel alternatives will “strand” fossil fuel assets, forcing companies to write them off.

…(read more).

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Lawsuits Mount Against Monsanto’s ‘Cancer-Causing’ Weedkiller

Lorraine Chow | October 16, 2015 11:04 am
Looks like the cancer lawsuits against Monsanto are gaining country-wide momentum. Reuters reports that personal injury law firms around the U.S. are gathering numerous plaintiffs to build “mass tort actions” alleging that exposure to the company’s popular weedkiller, Roundup, causes cancer.

Law firms—from California to New York City and nearly everywhere in between—are building cases against Monsanto. Numerous plaintiffs allege that exposure to the company’s flagship herbicide, Roundup, causes cancer. Photo credit: Flickr

A new lawsuit was filed in Delaware Superior Court on Wednesday by three law firms representing three plaintiffs. According to Reuters, plaintiff Joselin Barrera, 24, a child of migrant farm workers, claims her non-Hodgkin lymphoma stemmed from exposure to glyphosate, the key ingredient in Monsanto’s used weedkiller, Roundup. The other name on the suit, former migrant farm worker and landscaper Elias de la Garza, was also diagnosed with the same disease and has similar claims about the toxicity of the herbicide.

The new lawsuit is similar to Enrique Rubio v. Monsanto Company and Fitzgerald v. Monsanto Company, which were filed on the same day, Sept. 22, in Los Angeles and New York respectively. In these suits, former field worker Enrique Rubio (who has bone cancer) and horticultural assistant Judi Fitzgerald (who has leukemia) both claim that exposure to Roundup caused their diseases, and that Monsanto “falsified data” and “led a prolonged campaign of misinformation” to convince the public, farm workers and government agencies about the safety of the product.

(read more).

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Food-Matters

Drone Papers: Leaked Military Documents Expose US ‘Assassination Complex’

Based on cache of secret slides leaked by national security whistleblower, stunning exposé by The Intercept reveals inner workings—and failures—of the U.S. military’s clandestine efforts in Afghanistan, Yemen, and Somalia

by Nadia Prupis, staff writer

The Intercept has obtained a cache of secret slides that provides a window into the inner workings of the U.S. military’s kill/capture operations at a key time in the evolution of the drone wars — between 2011 and 2013. (Image: The Intercept)

A stunning new exposé by The Intercept, which includes the publication of classified documents leaked by an intelligence source, provides an unprecedented look at the U.S. military’s secretive global assassination program.

The series of articles, titled The Drone Papers, follows months of investigation and uses rare primary source documents and slides to reveal to the public, for the first time, the flaws and consequences of the U.S. military’s 14-year aerial campaign being conducted in Yemen, Somalia, and Afghanistan—one that has consistently used faulty information, killed an untold number of civilians, and stymied intelligence-gathering through its “kill/capture” program that too often relies on killing rather than capturing.

“The series is intended to serve as a long-overdue public examination of the methods and outcomes of America’s assassination program,” writes the investigation’s lead reporter, Jeremy Scahill. “This campaign, carried out by two presidents through four presidential terms, has been shrouded in excessive secrecy. The public has a right to see these documents not only to engage in an informed debate about the future of U.S. wars, both overt and covert, but also to understand the circumstances under which the U.S. government arrogates to itself the right to sentence individuals to death without the established checks and balances of arrest, trial, and appeal.”

…(read more)

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Conversations w/Great Minds: Alyssa Katz – The Influence Machine – The U.S. Chamber of Commerce


The Big Picture RT

Published on Oct 10, 2015

Alyssa Katz, THE INFLUENCE MACHINE: The U.S. Chamber of Commerce and the Corporate Capture of American Life joins Thom. How DID the Chamber of Commerce get so powerful? And what does that say about the corporate capture of our democracy?

Part 2:

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