Siberian Caves Reveal Advancing Permafrost Thaw

Melting of significant portions of Arctic permafrost could accelerate climate change into a catastrophe

By David Biello

PERMAFROST CAVE: The frost crystals at the entrance to the Ledyanaya Lenskaya cave in Russia denote the region's permafrost, which has been in place for roughly 400,000 years, according to the cave's speleothems. Image: Vladimir V Alexioglo

Permafrost is not so permanent. Across the Arctic, swathes of once-frozen-solid ground have begun to thaw. If the records preserved in Siberian caves are accurate, much more of the region could melt if temperatures continue to warm.

Geoscientist Anton Vaks of the University of Oxford led an international team of experts?including the Arabica Caving Club in Irkutsk?in sampling the spindly cave growths known as stalagmites and stalactites across Siberia and down into the Gobi Desert of China. Taking samples of such speleothems from six caves, the researchers then reconstructed the last roughly 500,000 years of climate via the decay of radioactive particles in the stone. When the ground is frozen above a cave no water seeps into it, making such formations "relicts from warmer periods before permafrost formed," the researchers wrote in a study published online in Science on 21 February.

The details of the study reveal that conditions were warm enough even in Siberia for these mineral deposits to form roughly 400,000 years ago, when the global average temperature was 1.5 degrees Celsius higher than present. It also suggests that there was no permafrost in the Lena River region at that time, because enough water seeped into the northernmost cave to enable roughly eight centimeters of growth in the formations.

That was, in fact, the last time the formations in the Ledyanaya Lenskaya Cave grew, although other caves further south showed multiple periods of growth coinciding with other warmer periods. "That boundary area of continuous permafrost starts to degrade when the mean global temperature is 1.5 degrees C higher than present," Vaks explains. "Such a warming is a threshold after which continuous permafrost zone starts to be vulnerable to global warming."

Since Vaks's present is the "preindustrial late Holocene," that means the planet is already more than halfway there, having experienced 0.8 degree C warming to date. Such a thaw is no small matter, given that permafrost covers nearly a quarter of the land in the Northern Hemisphere and holds roughly 1,700 gigatonnes of carbon?or roughly twice as much carbon as is currently trapping heat in the atmosphere. Much of that carbon would end up in the atmosphere if the permafrost was to thaw further.

That may not have occurred during the warm period 400,000 years ago, known as Marine Isotope Stage 11 to scientists, which featured elements such as boreal forest on Greenland and higher sea levels. "The thawing was probably very brief because the layer deposited in the northernmost cave stalactite was relatively thin," Vaks says?too thin in fact to determine how long the warm period lasted. "We don't see any extraordinary increase in atmospheric CO2 or methane during MIS-11." And the Gobi Desert might benefit, enjoying wetter conditions in the future if the record in these caves is accurate.

It's not clear how far north such thawing might extend if global average temperatures continue to warm until they match those from long ago. "Now we are looking for caves with speleothems in northern Siberia to answer this question," Vaks notes, adding that the northernmost cave is already much warmer than in the late 18th century based on historical reports. But it is clear that global climates not much warmer than present are enough to thaw even more permafrost?as far north as 60 degrees latitude.

"The potential impact of these results extends to global policy: these results indicate the potential release of large amounts of carbon from thawed permafrost even if we attain the 2 degree [C] warming target under negotiation," says Kevin Schaefer, a scientist at the U.S. National Snow and Ice Data Center, who has also studied permafrost but was not involved in this effort. "Permafrost thaws slowly and the carbon will be released into the atmosphere over two to three centuries."

Already, such thawing Arctic ice?whether underground or at sea?has further opened up the territory to exploration for resources, particularly oil. At the same time, the big thaw will make getting the oil out more expensive?billions of dollars in infrastructure investments in pipelines, roads and the like will be damaged as the ground shifts beneath them.

Source: http://rss.sciam.com/click.phdo?i=b81aff471deae6d179db06519bbc5891

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Lack of iron regulating protein contributes to high blood pressure of the lungs

Feb. 17, 2013 ? A protein known to regulate iron levels in the body has an unexpectedly important role in preventing a form of high blood pressure that affects the lungs, and in stabilizing the concentration of red cells in blood, according to a study in mice by researchers at the National Institutes of Health.

In mice, lack of iron regulatory protein 1 (Irp1) results in pulmonary hypertension, a form of high blood pressure that affects the lungs, and to polycythemia, a rare disorder in which the body produces excess red blood cells.

"This insight might lead to progress in treating cases of polycythemia or pulmonary hypertension without a known cause," said senior author Tracey A. Rouault, M.D., of the Division of Intramural Research (DIR) at the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), where the research was conducted. It's possible, she added, that human cases of these disorders might result from malfunctioning copies of the gene for Irp1.

The study also provides insight into how the body directs iron into the manufacture of blood to prevent anemia, the deficiency of red blood cells.

The findings appear in Cell Metabolism.

Dr. Rouault collaborated with more than a dozen other NIH researchers, including first authors Manik C. Ghosh, Ph.D., and Deliang Zhang, Ph.D., also of the NICHD's DIR, as well as researchers at the NIH Veterinary Resources Program and the National Heart, Lung and Blood Institute. Researchers from the University of Colorado School of Medicine, Denver, and the University of Nebraska-Lincoln were also part of the team.

Iron regulatory protein 1 (Irp1) detects iron levels in cells and directs either the storage or use of iron, depending on other conditions in the body. The researchers found that mice lacking Irp1 produced high levels of hypoxia inducible factor 2-alpha (HIF2 alpha), a protein produced in response to low oxygen conditions, like those that occur at high altitudes. In turn, HIF2 alpha spurs production of the hormone erythropoietin, which stimulates the production of red blood cells.

When the animals were put on low-iron diets, they did not become anemic, but instead developed polycythemia and pulmonary hypertension.

In people, polycythemia and high blood pressure in the lungs are rare conditions, and in some cases occur without a known cause. It is possible that changes in the gene for Irp1 may account for some of these cases, the researchers suggest.

To investigate Irp1's role in regulating the body's use of iron, the researchers reared mice lacking the gene that makes Irp1 and divided the animals into two groups, feeding one group a normal diet and the other a low iron diet.

Within a year, less than 40 percent of the mice on the low-iron diet had survived. Most had died from abdominal hemorrhaging. The researchers found that the mice on low iron diets had high levels of HIF2 alpha in the lungs and kidney. These animals produced high levels of erythropoietin, which resulted in polycythemia. HIF2 alpha also triggered increased production of a substance known as endothelin-1 in the lungs, which likely contributed to the development of pulmonary hypertension.

"Irp1 appears to be the switch that controls whether HIF2 alpha protein is made," Dr. Zhang said.

This research also provided insight into how Irp1 functions under normal circumstances Dr. Rouault explained. The researchers theorize that in low-iron conditions, Irp1 allows the production of HIF2 alpha. HIF2 alpha then triggers production of erythropoietin, to generate more red blood cells. To supply iron for the red blood cells, iron is removed from the tissues. When tissue iron levels decline too much, Irp1 halts production of HIF2 alpha, and production of new blood cells ceases, conserving the body's remaining iron stores. Production of red blood cells then declines, leading to anemia.

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The above story is reprinted from materials provided by NIH/National Institute of Child Health and Human Development (NICHD).

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Manik?C. Ghosh, De-Liang Zhang, Suh?Young Jeong, Gennadiy Kovtunovych, Hayden Ollivierre-Wilson, Audrey Noguchi, Tiffany Tu, Thomas Senecal, Gabrielle Robinson, Daniel?R. Crooks, Wing-Hang Tong, Kavitha Ramaswamy, Anamika Singh, Brian?B. Graham, Rubin?M. Tuder, Zu-Xi Yu, Michael Eckhaus, Jaekwon Lee, Danielle?A. Springer, Tracey?A. Rouault. Deletion of Iron Regulatory Protein 1 Causes Polycythemia and Pulmonary Hypertension in Mice through Translational Derepression of HIF2?. Cell Metabolism, 2013; 17 (2): 271 DOI: 10.1016/j.cmet.2012.12.016

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Source: http://feeds.sciencedaily.com/~r/sciencedaily/~3/fFp2oFXIYx4/130217165414.htm

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Legislators show no urgency in dealing with Florida springs' problems

The president of the state Senate says Florida should do more for its springs. Thousands of people have petitioned Gov. Rick Scott for more protection and restoration for the springs. A group of local government officials in North Florida has formed an activist group to push for legislation.

Yet with the Florida legislative session starting in less than a month, so far no one has filed a single springs-related bill.

"I guess there are no springs champions," said Jim Stevenson, who helped launch an initiative to rescue the springs that began under Gov. Jeb Bush and was abandoned in 2011 under Scott.

Florida's springs are in deep trouble. Although the state has more than 1,000 freshwater springs ? generally hailed as the greatest concentration of springs in the world ? many are suffering from nitrate pollution that fuels the growth of toxic algae blooms.

Compounding the problem is a decline in their flow that in some cases resulted in them sputtering out completely. And geologists have found a disturbing increase in saltiness in a few of freshwater springs, which could signal future problems with the state's drinking supply.

The springs initiative begun under Bush led to the state's purchase and preservation of thousands of acres of land that could have been developed or otherwise contributed to the pollution of the aquifer, Stevenson said.

But all of his group's recommendations for new laws were ignored by the Legislature ? except for one involving septic tank inspections, which was passed and then repealed before it took effect.

Because many of the springs are major tourist draws, their environmental woes have an economic impact. As a result, local officials across North Florida have formed their own group, Florida Leaders Organized for Water, or FLOW for short, to push for what they're calling the Fountain of Youth Springs Protection Act of 2013.

Their proposed bill calls for setting strict limits on the pollution flowing into the springs, reviewing all the water-pumping permits that have been issued around springs, setting a level for water use around the springs that ensures they will stay healthy and creating a new Florida Springs Task Force to provide annual reports to the Legislature on how all this is working out.

To pay for it, they propose a use fee on all for-profit water-bottling businesses in the state.

Ask White Springs Mayor Helen Miller, who's leading FLOW, how many legislators have lined up to sponsor this bill, and the answer is zero.

"We haven't been able to pick up a single sponsor," Miller said. "I guess the current feeling of this Legislature is that we don't have to deal with water. But clearly, the citizens of this state recognize the need for a serious policy discussion, more funding and more attention to our water problems."

Last year, springs advocates ? including former U.S. Sen. Bob Graham and former Nixon administration Deputy Interior Secretary Nathaniel Reed ? rounded up 15,000 signatures on a petition demanding the state do more to protect Silver, Rainbow and other popular springs, and sent it to the governor and the state Department of Environmental Protection.

The one bright spot for springs advocates is in the proposed budget offered by Scott. The budget contain $6 million for springs restoration work, which is $3?million more than last year ? although that's nowhere near the $122 million that state water officials have requested. The budget also includes $500,000 to help farmers in springs areas retrofit their thirsty center-pivot irrigation systems with something that will slurp up less water from the aquifer.

Legislative leaders aren't convinced the situation is all that dire. Senate President Don Gaetz, R-Niceville, said of the springs, "We need to do more than we're doing now." But he indicated he regards the projected cost as potentially excessive, calling it "a heck of a big number."

House Speaker Will Weatherford, R-Wesley Chapel, contends the Legislature isn't the one that's responsible for fixing what's wrong with the springs.

"I'm not a scientist, man," Weatherford said, acknowledging he had heard something about the problems facing the springs but lacked specifics. Then he added, "But that's what we have water management districts for."

When a reporter pointed out that the Legislature has imposed deep cuts in the water agencies' budgets, hampering their ability to take action on springs, Weatherford said they still had plenty of money, but weren't spending it the right way.

"Maybe they should be buying less land and instead investing in our water resources to make sure they're protected," the speaker said.

Miller said that sounded like Weatherford is passing the buck, and as for Gaetz's concern regarding the cost: "What's the cost to the state of not dealing effectively with our water issues now?"

Craig Pittman can be reached at craig@tampabay.com.

Source: http://www.tampabay.com/news/environment/water/legislators-show-no-urgency-in-dealing-with-florida-springs-problems/1274681

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