Archive for the ‘environment’ Category

Global warming is affecting the world’s lakes

May 18, 2017

Lakes worldwide feel the heat from climate change, Warming waters are disrupting freshwater fishing and recreation, Science News ,BY ALEXANDRA WITZE  MAY 1, 2017 “……..When most people think of the physical effects of climate change, they picture melting glaciers, shrinking sea ice or flooded coastal towns (SN: 4/16/16, p. 22). But observations like those at Stannard Rock are vaulting lakes into the vanguard of climate science. Year after year, lakes reflect the long-term changes of their environment in their physics, chemistry and biology. “They’re sentinels,” says John Lenters, a limnologist at the University of Wisconsin–Madison.

Globally, observations show that many lakes are heating up — but not all in the same way or with the same ecological consequences. In eastern Africa, Lake Tanganyika is warming relatively slowly, but its fish populations are plummeting, leaving people with less to eat. In the U.S. Upper Midwest, quicker-warming lakes are experiencing shifts in the relative abundance of fish species that support a billion-dollar-plus recreational industry. And at high global latitudes, cold lakes normally covered by ice in the winter are seeing less ice year after year — a change that could affect all parts of the food web, from algae to freshwater seals.

Understanding such changes is crucial for humans to adapt to the changes that are likely to come, limnologists say. Indeed, some northern lakes will probably release more methane into the air as temperatures rise — exacerbating the climate shift that is already under way.

Lake layers

Lakes and ponds cover about 4 percent of the land surface not already covered by glaciers. That may sound like a small fraction, but lakes play a key role in several planetary processes. Lakes cycle carbon between the water’s surface and the atmosphere. They give off heat-trapping gases such as
carbon dioxide and methane, while simultaneously tucking away carbon in decaying layers of organic muck at lake bottoms. They bury nearly half as much carbon as the oceans do.

Yet the world’s more than 100 million lakes are often overlooked in climate simulations. That’s surprising, because lakes are far easier to measure than oceans. Because lakes are relatively small, scientists can go out in boats or set out buoys to survey temperature, salinity and other factors at different depths and in different seasons.

A landmark study published in 2015 aimed to synthesize these in-water measurements with satellite observations for 235 lakes worldwide. In theory, lake warming is a simple process: The hotter the air above a lake, the hotter the waters get. But the picture is far more complicated than that, the international team of researchers found.

Globally, observations show that many lakes are heating up — but not all in the same way or with the same ecological consequences. In eastern Africa, Lake Tanganyika is warming relatively slowly, but its fish populations are plummeting, leaving people with less to eat. In the U.S. Upper Midwest, quicker-warming lakes are experiencing shifts in the relative abundance of fish species that support a billion-dollar-plus recreational industry. And at high global latitudes, cold lakes normally covered by ice in the winter are seeing less ice year after year — a change that could affect all parts of the food web, from algae to freshwater seals.

Understanding such changes is crucial for humans to adapt to the changes that are likely to come, limnologists say. Indeed, some northern lakes will probably release more methane into the air as temperatures rise — exacerbating the climate shift that is already under way.

Lake layers

Lakes and ponds cover about 4 percent of the land surface not already covered by glaciers. That may sound like a small fraction, but lakes play a key role in several planetary processes. Lakes cycle carbon between the water’s surface and the atmosphere. They give off heat-trapping gases such as
carbon dioxide and methane, while simultaneously tucking away carbon in decaying layers of organic muck at lake bottoms. They bury nearly half as much carbon as the oceans do.

Yet the world’s more than 100 million lakes are often overlooked in climate simulations. That’s surprising, because lakes are far easier to measure than oceans. Because lakes are relatively small, scientists can go out in boats or set out buoys to survey temperature, salinity and other factors at different depths and in different seasons.

A landmark study published in 2015 aimed to synthesize these in-water measurements with satellite observations for 235 lakes worldwide. In theory, lake warming is a simple process: The hotter the air above a lake, the hotter the waters get. But the picture is far more complicated than that, the international team of researchers found.

On average, the 235 lakes in the study warmed at a rate of 0.34 degrees Celsius per decade between 1985 and 2009. Some warmed much faster, like Finland’s Lake Lappajärvi, which soared nearly 0.9 degrees each decade. A few even cooled, such as Blue Cypress Lake in Florida. Puzzlingly, there was no clear trend in which lakes warmed and which cooled. The most rapidly warming lakes were scattered across different latitudes and elevations.

Even some that were nearly side by side warmed at different rates from one another — Lake Superior, by far the largest of the Great Lakes, is warming much more rapidly, at a full degree per decade, than others in the chain, although Huron and Michigan are also warming fast.

“Even though lakes are experiencing the same weather, they are responding in different ways,” says Stephanie Hampton, an aquatic biologist at Washington State University in Pullman.

Such variability makes it hard to pin down what to expect in the future. But researchers are starting to explore factors such as lake depth and lake size (intuitively, it’s less teeth-chattering to swim in a small pond in early summer than a big lake).

Depth and size play into stratification, the process through which some lakes separate into layers of different temperatures. …….https://www.sciencenews.org/article/lakes-worldwide-feel-heat-climate-change?tgt=nr

The vanishing Arctic ice

May 18, 2017

The hard truth, however, is that the Arctic as it is known today is almost certainly gone. Efforts to mitigate global warming by cutting emissions remain essential. But the state of the Arctic shows that humans cannot simply undo climate change. They will have to adapt to it

The Arctic as it is known today is almost certainly gone On current trends, the Arctic will be ice-free in summer by 2040 http://www.economist.com/news/leaders/21721379-current-trends-arctic-will-be-ice-free-summer-2040-arctic-it-known-today?fsrc=scn/tw/te/bl/ed/climatechangethearcticasitisknowntodayisalmostcertainlygone Apr 29th 2017

THOSE who doubt the power of human beings to change Earth’s climate should look to the Arctic, and shiver. There is no need to pore over records of temperatures and atmospheric carbon-dioxide concentrations. The process is starkly visible in the shrinkage of the ice that covers the Arctic ocean. In the past 30 years, the minimum coverage of summer ice has fallen by half; its volume has fallen by three-quarters. On current trends, the Arctic ocean will be largely ice-free in summer by 2040.

Climate-change sceptics will shrug. Some may even celebrate: an ice-free Arctic ocean promises a shortcut for shipping between the Pacific coast of Asia and the Atlantic coasts of Europe and the Americas, and the possibility of prospecting for perhaps a fifth of the planet’s undiscovered supplies of oil and natural gas. Such reactions are profoundly misguided. Never mind that the low price of oil and gas means searching for them in the Arctic is no longer worthwhile. Or that the much-vaunted sea passages are likely to carry only a trickle of trade. The right response is fear. The Arctic is not merely a bellwether of matters climatic, but an actor in them (see Briefing).

The current period of global warming that Earth is undergoing is caused by certain gases in the atmosphere, notably carbon dioxide. These admit heat, in the form of sunlight, but block its radiation back into space, in the form of longer-wavelength infra-red. That traps heat in the air, the water and the land. More carbon dioxide equals more warming—a simple equation. Except it is not simple. A number of feedback loops complicate matters. Some dampen warming down; some speed it up. Two in the Arctic may speed it up quite a lot.

One is that seawater is much darker than ice. It absorbs heat rather than reflecting it back into space. That melts more ice, which leaves more seawater exposed, which melts more ice. And so on. This helps explain why the Arctic is warming faster than the rest of the planet. The deal on climate change made in Paris in 2015 is meant to stop Earth’s surface temperature rising by more than 2°C above pre-industrial levels. In the unlikely event that it is fully implemented, winter temperatures over the Arctic ocean will still warm by between 5° and 9°C compared with their 1986-2005 average.

The second feedback loop concerns not the water but the land. In the Arctic much of this is permafrost. That frozen soil locks up a lot of organic material. If the permafrost melts its organic contents can escape as a result of fire or decay, in the form of carbon dioxide or methane (which is a more potent greenhouse gas than CO2). This will speed up global warming directly—and the soot from the fires, when it settles on the ice, will darken it and thus speed its melting still more.

Dead habitat walking

 A warming Arctic could have malevolent effects. The world’s winds are driven in large part by the temperature difference between the poles and the tropics. If the Arctic heats faster than the tropics, this difference will decrease and wind speeds will slow—as they have done, in the northern hemisphere, by between 5 and 15% in the past 30 years. Less wind might sound desirable. It is not. One consequence is erratic behaviour of the northern jet stream, a circumpolar current, the oscillations of which sometimes bring cold air south and warm air north. More exaggerated oscillations would spell blizzards and heatwaves in unexpected places at unexpected times.

Ocean currents, too, may slow. The melting of Arctic ice dilutes salt water moving north from the tropics. That makes it less dense, and thus less inclined to sink for the return journey in the ocean depths. This slowing of circulation will tug at currents around the world, with effects on everything from the Indian monsoon to the pattern of El Niño in the Pacific ocean.

The scariest possibility of all is that something happens to the ice cap covering Greenland. This contains about 10% of the world’s fresh water. If bits of it melted, or just broke free to float in the water, sea levels could rise by a lot more than today’s projection of 74cm by the end of the century. At the moment, the risk of this happening is hard to assess because data are difficult to gather. But loss of ice from Greenland is accelerating.

What to do about all this is a different question. Even if the Paris agreement is stuck to scrupulously, the amount of carbon dioxide already in the atmosphere, together with that which will be added, looks bound eventually to make summer Arctic sea ice a thing of the past. Some talk of geoengineering—for example, spraying sulphates into the polar air to reflect sunlight back into space, or using salt to seed the creation of sunlight-blocking clouds. Such ideas would have unknown side-effects, but they are worth testing in pilot studies.

The hard truth, however, is that the Arctic as it is known today is almost certainly gone. Efforts to mitigate global warming by cutting emissions remain essential. But the state of the Arctic shows that humans cannot simply undo climate change. They will have to adapt to it.

Radioactive pollution and the health of babies

May 18, 2017

Fracking kills newborn babies – polluted water likely cause http://www.theecologist.org/News/news_round_up/2988876/fracking_kills_newborn_babies_polluted_water_likely_cause.htmlOliver Tickell, 25th April 2017  A new study in Pennsylvania, USA shows that fracking is strongly related to increased mortality in young babies. The effect is most pronounced in counties with many drinking water wells indicating that contamination by ‘produced water’ from fracking is a likely cause. Radioactive pollution with uranium, thorium and radium is a ‘plausible explanation’ for the excess deaths.

A new study of Pennsylvania counties published today in the Journal of Environmental Protection shows for the first time that contamination from fracking kills babies.

The Marcellus shale area of Pennsylvania was one of the first regions where novel gas drilling involving hydraulic fracturing of sub-surface rock, now termed ‘fracking’, was carried out.

The epidemiological study by Christopher Busby and Joseph Mangano examines early infant deaths 0-28 days before and after the drilling of fracking wells, using official data from the US Centre for Disease Control to compare the immediate post-fracking four year period 2007-2010 with the pre-fracking four-year period 2003-2006.

Results showed a statistically significant 29% excess risk of dying age 0-28 days in the ten heavily fracked counties of Pennsylvania during the four-year period following the development of fracking gas wells. Over the same period, the State rate declined by 2%. They conclude:

“There were about 50 more babies died in these 10 counties than would have been predicted if the rate had been the same over the period as all of Pennsylvania, where the incidence rate fell over the same period.”

Radioactive water pollution to blame?

The Marcellus shale beneath Pennsylvania was one of the first areas where fracking began. Only 44 fracking wells were drilled before 2007, while 2,864 were drilled in 2007-2010.

The cause of the excess mortality is not proven in the study, however the authors point out that the fracking production process releases naturally occurring radioactive materials from shale strata which then contaminate groundwater.

These include radium, uranium, thorium and radon, an intensely radioactive gas which decays into radioactive ‘daughters’ with a half life of under four days. And as the authors write, fracking “involves the explosive destruction of large volumes of underground gas and oil retaining rocks and the pumping down of large amounts of what is termed ‘produced water’ which initially contains various chemical and sand additives.

“This produced water and backflow returns to the surface with a high load of dissolved and suspended solids including naturally occurring radioactive elements … The contaminated water has to be safely disposed of but this is often associated with violations of legal disposal constraints.”

Baby mortality related to exposure through water wells

In the five heavily-fracked counties in the northeast part of the state (Susquehanna, Bradford, Wyoming, Lycoming and Tioga), the number of deaths from 2003-2006 vs. 2007-2010 climbed from 36 to 60, a statistically significant rate increase of 66%.

The rate in the five counties in southwest Pennsylvania (Washington, Westmoreland, Greene, Butler and Fayette) rose 18%, from 157 to 178 deaths, though this increase was not statistically significant.

This divergence in relative risk between the heavily fracked NE and SW counties was initially perplexing, however the authors noticed the higher dependence on private water wells (potentially contaminated with frackiing fluids) for drinking water and other needs in the first region compared to the second.

In the NE group of counties , the number of water wells per birth ranged from 4.9 to 13.5, compared to 1.1 to 3 in the SW group of countries. Their chart of Relative Risk for early infant mortality after fracking (see image above right) plotted against ‘exposure’ defined as ‘water wells per birth’ on a county by county basis produced a straight-line graph – indicated a strong relation to increased mortality and exposure to groundwater.

Table [on original]: Water wells per birth and violations per annual birth in highly fracked Pennsylvania Counties.

They conclude: “The results therefore seem to support the suggestion that the vector for the effect is exposure to drinking water from private wells. This is a mechanistically plausible explanation. However the findings do not prove such a suggestion. We may examine other possible explanations for possible health effects which have been advanced.”

While radioactive pollution is carefully examined, the authors acknowledge alternatives including “the existence of chemical contaminants in the produced water” which they consider a “possible but unknown factor.”

Serious questions raised over health hazards of fracking

“A major component of early infant mortality is congenital malformation, e.g., heart, neurological, and kidney defects. These are known to be caused by exposures to Radium and Uranium in drinking water”, said Christopher Busby.

“Infant death rates were significantly high in highly-fracked counties in northeast Pennsylvania, those with the greatest density of private water wells, suggesting it is drinking water contamination driving the effect.”

Joseph Mangano added: “These results raise serious questions about potential health hazards of fracking, especially since the fetus and infant are most susceptible to environmental pollutants. This is a public health issue which should be investigated wherever fracking is being carried out or proposed.”

The result is expected to have significant insurance, investment, economic and downstream political implications in the US and other countries.

The study: ‘There’s a world going on underground-infant mortality and fracking in Pennsylvania‘ is by Busby C C and Mangano J J and published in the Journal of Environmental Protection 8(4) 2017. doi: 10.4236/jep.2017.84028

Dr Busby is the Scientific Secretary of the European Committee on Radiation Risk www.ecrr.eu and is Scientific Director of Environmental Research SIA, based in the Latvian National Academy of Sciences, Riga, Latvia. Busby’s CV can be found here.

Chernobyl and its radioactive berry harvests

May 18, 2017

The harvests of Chernobyl, Aeon, Thirty years after the nuclear disaster, local berry-pickers earn a good living. What’s the hidden cost of their wares?, Kate Brown, is associate professor of history at the University of Maryland, Baltimore County, and the author of Plutopia (2013). Olha Martynyuk is a historian at the National Technical University of Ukraine.

You can’t miss the berry-pickers in the remote forests of northern Ukraine, a region known as Polesia. They ride along on bicycles or pile out of cargo vans. They are young, mostly women and children, lean and suntanned, with hands stained a deep purple. And they are changing the landscape around them. Rural communities across eastern Europe are struggling economically, but the Polesian towns are booming with new construction. Two hundred miles west of the Chernobyl Nuclear Power Plant, thousands of mushroom- and berry-pickers are revving up the local economy. As they forage, they are even changing the European diet, in ways both culinary and radiological.
The rise of the Polesian pickers adds a strange twist to the story that began on 26 April 1986, when an explosion at the Chernobyl plant blew out at least 50 million curies of radioactive isotopes. Soviet leaders traced out a 30 kilometre radius around the stricken reactor and emptied it of its residents. Roughly 28,000 square kilometres outside this exclusion zone were also contaminated. In total, 130,000 people were resettled, but hundreds of thousands remained on irradiated territory, including the Polesian towns of Ukraine’s Rivne Province. In 1990, Soviet officials resolved to resettle several hundred thousand more residents but ran out of money to carry out new mass evacuations.

Last summer, we went to Rivnе to talk to people who in the late 1980s wrote petitions begging for resettlement. In the letters, which we had found in state archives in Kiev and Moscow, writers expressed worries about their health and that of their children, while describing a sense of abandonment. Help never arrived; the Chernobyl accident came just as the Soviet state began to topple economically and politically……..

Anyone in Polesia can pick anywhere, as long as they are willing to brave the radioactive isotopes. After Chernobyl, Soviet officials strongly discouraged picking berries in contaminated forest areas, which promised to remain radioactive for decades. As the years passed, fewer and fewer people heeded the warnings. In the past five years, picking has grown into a booming business as new global market connections have enabled the mass sale of berries abroad. A person willing to do the hard work of stooping 10 hours a day and heaving 40-pound boxes of fruit to the road can earn good money. The women and child pickers are revitalising the Polesian economy on a modest, human-powered scale. They are quietly and unceremoniously doing what development agencies and government programmes failed to do: restoring commercial activity to the contaminated territory around the Chernobyl Zone.

We followed the pickers into the woods. …….

Reliance on the forest for a living is an ancestral tradition in Polesia. Because of the mineral-poor soils, traditional farming never thrived here. Instead, Polesians subsisted on game, fish, berries, herbs and mushrooms while making their tools and homes from wood and clay. What is new in the past few years is the industrial-sized scale of berry harvesting. A typical roadside berry-buyer purchases about two tons of berries a day in season, and there are hundreds of buyers. In 2015, Ukraine exported 1,300 tons of fresh berries and 17,251 tons of frozen berries to the European market – more than 30 times as much as in 2014. Ukraine is now one of biggest exporters of blueberries to the EU.

That success is all the more remarkable because Polesian berries are not just any berries. They grow in radioactive soils, which means that they carry some of Chernobyl’s legacy in them. We showed up at a berry wholesaler in the boom town of Rokytne and noticed a radiation monitor who was stationed to meet buyers at the loading dock. The situation there was tense. As the monitor waved a wand over each box of berries, measuring their gamma ray emission, she set aside about half of the boxes. The buyers argued with her, trying to lower the count on their berries: ‘It’s not the berries that are radiating. It’s my trailer. Measure it over there.’

We asked the monitor, a young townswoman, how many berries come up radioactive. ‘All the berries from Polesia are radioactive,’ she replied, ‘but some are really radioactive. We’ve had berries measure over 3,000!’ She could not describe what units she was referring to, microsieverts or microrems; she only knew which numbers were bad. ‘The needle has to be between 10 and 15,’ she said, vaguely pointing to her wand, ‘and then I place it in this machine.’ She gestured toward a small mass spectrometer. ‘If the readout is more than 450, then the berries are over the permissible level.’

Contrary to our assumption, the berries rejected as too radioactive were not discarded, but were merely placed aside. Then they, too, were weighed and sold, just at lower prices. The wholesalers we spoke to said that the radioactive berries were used for natural dyes. The pickers claimed the hot berries were mixed with cooler berries until the assortment came in under the permissible level. The berries could then legally be sold to Poland to enter the European Union (EU) market, even if some individual berries measured five times higher than the permissible level. Such mixing is legal as long as the overall mix of berries falls within the generous limit of 600 becquerel per kilogram set by the EU after the Chernobyl disaster.

No one, certainly no official, ever envisioned revitalising the economy by exploiting berries and mushrooms. Months after the 1986 accident, Soviet scientists determined that forest products were the most radioactive of all edible crops, and banned their consumption. However, villagers in Polesia never stopped harvesting berries and mushrooms (as well as game and fish) from the forests outside the fenced-off Chernobyl Zone. Women sold their produce surreptitiously at regional markets, deftly avoiding the police who learned to identify Polesians by their homemade baskets……..

AQlthough the Polesian berries meet EU standards, it remains unclear how healthy life is for those living in the Rivne Province. Official publications of the World Health Organization and the International Atomic Energy Agency assert that radiation levels in Polesia are too low to cause health damage other than a slight rise in the chance of cancer. However, that judgment is based on reference studies of Hiroshima and Nagasaki victims, not on local research in the Chernobyl zones. Wladimir Wertelecki, a geneticist at the University of California, San Diego, has spent the past 16 years tracking every recorded birth in the Rivne Province. ‘Hiroshima was just one big X-ray. It doesn’t compare to the doses of people in Polesia who ingest radioactive isotopes every day,’ he says. He thinks that the slow-drip exposure of organs to radioactive isotopes over decades makes for a far more damaging exposure than the single, external Hiroshima dose.

Researchers in Wertelecki’s group and those working on small, usually minimally financed medical studies have found that low doses of ingested radiation tend to concentrate in vital organs that keenly impact on important body functions. Yury Bandazhevsky, a pioneer in studying the health impacts of Chernobyl, has recorded a correlation between the incorporation of radioactive cesium in children’s bodies and heart disease in Belarus and Ukraine. Wertelecki and the Ukrainian medical researcher Lyubov Yevtushok discovered that in the six Polesian regions of the Rivne Province, certain birth defects, such as microcephaly, conjoined twins and neural-tube disorders occur three times more frequently than is the European norm. ‘We did not prove with this study that radiation causes birth defects. We just have a concurrence, not proof, of cause and effect,’ Wertelecki says. Nevertheless, he considers the concurrence statistically strong enough to warrant large-scale epidemiological studies that could prove or disprove whether the birth defects were caused by radiation.

Despite the fact that the nuclear disaster presented scientists with a unique living laboratory, few funding agencies have been willing to finance Chernobyl studies on non-cancerous health effects; based on Japanese bomb-survivor research, industry scientists have insisted that there would be no measurable non-malignant impacts. In Chernobyl-contaminated Polesia, however, few people doubt that ingesting radioactive toxins over decades has a biological cost.

Galina, the woman who declared that there was ‘no Chernobyl’, changed her view later when talking about her own health. Trim and fit at the age of 50, she had a stroke followed by two surgeries for ‘women’s cancer’. About her cancers, she said: ‘All of a sudden, they started growing day by day. I asked the doctors if they’d hold up the operation until autumn [after the harvest], but they said I’d be dead by then. Probably, these problems were caused by radiation. It does have an effect, apparently.’ Even less is known about non-cancer health impacts from Chernobyl. Many locals complain of aching and swollen joints, headaches, chronic fatigue and legs that mysteriously stop moving. There have been almost no studies investigating these vague complaints…….

here has been little public discussion and almost no medical research on the long-term, low-dose ingestion of radioactive isotopes. Presumably exporting the berries helps the people of Polesia, but for now there is no hard proof……

The mass marketing of radioactive Polesian forest products is an unexpected outcome of policies aimed at finalising the disaster. It is a development that disputes the focus on Chernobyl as a ‘place’. Rather, Chernobyl is an event, an ongoing occurrence that transpires as long as the radioactive energy released in the accident continues to decay…….https://aeon.co/essays/ukraine-s-berry-pickers-are-reaping-a-radioactive-bount

Arctic warm water is now being pushed to the surface

May 18, 2017
Climate change is literally turning the Arctic ocean inside out, WP,  April 6 There’s something special — and very counterintuitive — about the Arctic Ocean.

Unlike in the Atlantic or Pacific, where the water gets colder as it gets deeper, the Arctic is upside-down. The water gets warmer as it gets deeper. The reason is that warm, salty Atlantic-originating water that flows into the Arctic from the south is more dense, and so it nestles beneath a colder, fresher surface layer that is often capped by floating sea ice. This state of “stratification” makes the Arctic Ocean unique, and it means that waters don’t simply grow colder as you travel farther north — they also become inverted.

But in a paper in Science released Thursday, a team of Arctic scientists say this fundamental trait is now changing across a major part of the Arctic, in conjunction with a changing climate.

“I first went to the Arctic in about 1969, and I’ve never seen anything like this,” said Eddy Carmack, a researcher with Fisheries and Oceans Canada and one of the study’s authors. “Back then we just assumed the Arctic is as it is and it will be that way forevermore. So what we’re seeing in the last decade or so is quite remarkable.”

In a large area that they term the eastern Eurasian basin — north of the Laptev and East Siberian seas, which in turn are north of Siberia — the researchers found that warm Atlantic water is increasingly pushing to the surface and melting floating sea ice. This mixing, they say, has not only contributed to thinner ice and more areas of open water that used to be ice covered, but it also is changing the state of Arctic waters in a process the study terms “Atlantification” — and these characteristics could soon spread across more of the Arctic ocean, changing it fundamentally.

The study was led by Igor Polyakov of the University of Alaska at Fairbanks, in collaboration with a team of 15 researchers from the United States, Canada, Russia, Poland, Germany and Norway.

To understand the work, it’s important to first note the extensive and rapid shrinkage of Arctic sea ice of late in an area to the north of Siberia. The area, known as the eastern Eurasian basin, is seeing thinner ice and more months of open water. Arctic sea ice is a linchpin of the Earth’s climate system………https://www.washingtonpost.com/news/energy-environment/wp/2017/04/06/scientists-say-the-unique-arctic-ocean-is-being-transformed-before-our-eyes/?utm_campaign=crowdfire&utm_content=crowdfire&utm_medium=social&utm_source=twitter&utm_term=.40ec22cba221#350509998-tw#1491570060364

Radiation and milk

March 9, 2017

What’s up with milk and radiation? , Connect Savannah, 14 Sept 2011, 

1. It’s a food. While an external dusting of radionuclides isn’t healthy, for efficient long-term irradiation of vulnerable organs there’s no substitute for actually ingesting the stuff.

2. It’s fast. Not to knock potatoes and chicken, but growing these items can take weeks or months. With milk, the fallout simply drifts over the pasture and lands on the grass, which the cows then eat. The radioactive particles are deposited in the cows’ milk, the farmers milk the cows, and in a day or two the contaminated product shows up in the dairy case.

3. Because it’s processed quickly, milk makes effective use of contaminants that would otherwise rapidly decay. A byproduct of uranium fission is the radioactive isotope iodine-131. Iodine is critical to functioning of the thyroid gland, and any iodine-131 consumed will be concentrated there. However, iodine-131 has a half-life of just eight days. The speed of dairying eliminates this impediment.

4. Milk also does a good job of delivering other radioactive contaminants, such as cesium-134 and cesium-137. Although not important for human health, radioactive cesium mimics potassium, which we do need, and is readily absorbed by the body. Another uranium breakdown product is strontium-90, which is especially hazardous to children, since it can be incorporated into growing bones. In contrast to radioactive iodine, strontium-90 has a half-life of about 29 years, so once it gets embedded in you, you are, as the Irish say, fooked.

5. That brings us to the most fiendish property of radioactive milk-it targets the young. Children (a) drink a lot more milk and (b) are smaller, which when you add it up means they get a much stiffer dose. Some cancers triggered by radioactivity have a long latency period; older people may die of something else first, but kids bear the full brunt.

For all these reasons, testing milk and dumping any contaminated is at the top of the list of disaster-response measures following a nuclear accident, and it’s unusual, though not unknown, for bad milk to find its way into the food supply. For example:

• Iodine contamination during the 1979 Three Mile Island accident was negligible, 20 picocuries per liter. The FDA’s “action level” at the time was 12,000 picocuries per liter; the current limit of 4,600 picocuries is still far in excess of what was observed.

• After the problems with the Fukushima reactors in Japan, one batch of hot milk did test at nine times the current limit, and milk and vegetable consumption was prohibited in high-risk areas. But most bans were rescinded after a couple months.

• In 1957, after a fire at the Windscale plutonium processing plant in the UK, radiation levels of 800,000 picocuries per liter and higher were found in local milk. Though contamination of milk wasn’t well understood at the time, authorities figured 800,000 of anything involving curies can’t be good and banned the stuff.

• Then there’s Chernobyl. Milk sales were banned in nearby cities after the 1986 reactor explosion, but feckless Soviet officials let the sizable rural population fend for itself. Not surprisingly, 6,000 cases of thyroid cancer subsequently developed, proving there’s no catastrophic situation that stupidity can’t make worse.

One last thing. We’ve been talking about cow’s milk, but be aware that iodine-131, strontium-90, and other radioactive contaminants can also be transferred through human milk…..http://www.connectsavannah.com/savannah/whats-up-with-milk-and-radiation/Content?oid=2135647

Ocean acidification spreading rapidly in Arctic Ocean,

March 9, 2017

International team reports ocean acidification spreading rapidly in Arctic Ocean, EurekAlert, 28 Feb 17, UNIVERSITY OF DELAWARE  Ocean acidification (OA) is spreading rapidly in the western Arctic Ocean in both area and depth, according to new interdisciplinary research reported in Nature Climate Changeby a team of international collaborators, including University of Delaware professor Wei-Jun Cai.

The research shows that, between the 1990s and 2010, acidified waters expanded northward approximately 300 nautical miles from the Chukchi slope off the coast of northwestern Alaska to just below the North Pole. Also, the depth of acidified waters was found to have increased, from approximately 325 feet to over 800 feet (or from 100 to 250 meters).

“The Arctic Ocean is the first ocean where we see such a rapid and large-scale increase in acidification, at least twice as fast as that observed in the Pacific or Atlantic oceans,” said Cai, the U.S. lead principal investigator on the project and Mary A.S. Lighthipe Professor of Earth, Ocean, and Environment at UD.

“The rapid spread of ocean acidification in the western Arctic has implications for marine life, particularly clams, mussels and tiny sea snails that may have difficulty building or maintaining their shells in increasingly acidified waters,” said Richard Feely, NOAA senior scientist and a co-author of the research. Sea snails called pteropods are part of the Arctic food web and important to the diet of salmon and herring. Their decline could affect the larger marine ecosystem.

Among the Arctic species potentially at risk from ocean acidification are subsistence fisheries of shrimp and varieties of salmon and crab.

Other collaborators on the international project include Liqi Chen, the Chinese lead principal investigator and scientist with the Third Institute of Oceanography of State Oceanic Administration of China; and scientists at Xiamen University, China and the University of Gothenburg, Sweden, among other institutions…….

Arctic ocean ice melt in the summer, once found only in shallow waters of depths less than 650 feet or 200 meters, now spreads further into the Arctic Ocean.

“It’s like a melting pond floating on the Arctic Ocean. It’s a thin water mass that exchanges carbon dioxide rapidly with the atmosphere above, causing carbon dioxide and acidity to increase in the meltwater on top of the seawater,” said Cai. “When the ice forms in winter, acidified waters below the ice become dense and sink down into the water column, spreading into deeper waters.”https://www.eurekalert.org/pub_releases/2017-02/uod-itr022717.php

Possibility of drastic cooling in North Atlantic

March 9, 2017

Drastic cooling in North Atlantic beyond worst fears, scientists warn https://www.theguardian.com/environment/2017/feb/24/drastic-cooling-north-atlantic-beyond-worst-fears-scientists-warn

Climatologists say Labrador Sea could cool within a decade before end of this century, leading to unprecedented disruption, reports Climate News Network, Guardian,  , 25 Feb 17, For thousands of years, parts of northwest Europe have enjoyed a climate about 5C warmer than many other regions on the same latitude. But new scientific analysis suggests that that could change much sooner and much faster than thought possible.

Climatologists who have looked again at the possibility of major climate change in and around the Atlantic Ocean, a persistent puzzle to researchers, now say there is an almost 50% chance that a key area of the North Atlantic could cool suddenly and rapidly, within the space of a decade, before the end of this century.

That is a much starker prospect than even the worst-case scientific scenario proposed so far, which does not see the Atlantic ocean current shutdown happening for several hundred years at least.

A scenario even more drastic (but fortunately fictional) was the subject of the 2004 US movie The Day After Tomorrow, which portrayed the disruption of the North Atlantic’s circulation leading to global cooling and a new Ice Age.

To evaluate the risk of extreme climate change, researchers from the Environnements et Paléoenvironnements Océaniques et Continentaux laboratory (CNRS/University of Bordeaux, France), and the University of Southamptondeveloped an algorithm to analyse the 40 climate models considered by the Fifth Assessment Report.

The findings by the British and French team, published in the Nature Communications journal, in sharp contrast to the IPCC, put the probability of rapid North Atlantic cooling during this century at almost an even chance – nearly 50%.

Current climate models foresee a slowing of the meridional overturning circulation (MOC), sometimes known also as the thermohaline circulation, which is the phenomenon behind the more familiar Gulf Stream that carries warmth from Florida to European shores. If it did slow, that could lead to a dramatic, unprecedented disruption of the climate system.

In 2013, drawing on 40 climate change projections, the IPCC judged that this slowdown would occur gradually, over a long period. Its findings suggested that fast cooling of the North Atlantic during this century was unlikely.

But oceanographers from EU emBRACE had also re-examined the 40 projections by focusing on a critical spot in the northwest of the North Atlantic: the Labrador Sea.

The Labrador Sea is host to a convection system ultimately feeding into the ocean-wide MOC. The temperatures of its surface waters plummet in the winter, increasing their density and causing them to sink. This displaces deep waters, which bring their heat with them as they rise to the surface, preventing the formation of ice caps.

The algorithm developed by the Anglo-French researchers was able to detect quick sea surface temperature variations. With it they found that seven of the 40 climate models they were studying predicted a total shutdown of convection, leading to abrupt cooling of the Labrador Sea by 2C to 3C over less than 10 years. This in turn would drastically lower North Atlantic coastal temperatures.

But because only a handful of the models supported this projection, the researchers focused on the critical parameter triggering winter convection: ocean stratification. Five of the models that included stratification predicted a rapid drop in North Atlantic temperatures.

The researchers say these projections can one day be tested against real data from the international OSnap project, whose teams will be anchoring scientific instruments within the sub-polar gyre (a gyre is any large system of circulating ocean currents).

If the predictions are borne out and the North Atlantic waters do cool rapidly over the coming years, the team says, with considerable understatement, climate change adaptation policies for regions bordering the North Atlantic will have to take account of this phenomenon.

NASA project – Oceans Melting Greenland (OMG) studies future sea level rise

March 9, 2017

OMG measurements of Greenland give us a glimpse of future sea rise https://www.skepticalscience.com/omg-greenland-sea-level-rise.html 24 February 2017 by John Abraham  If you meet a group of climate scientists, and ask them how much sea levels will rise by say the year 2100, you will get a wide range of answers. But, those with most expertise in sea level rise will tell you perhaps 1 meter (a little over three feet). Then, they will immediately say, “but there is a lot of uncertainty on this estimate.” It doesn’t mean they aren’t certain there will be sea level rise – that is guaranteed as we add more heat in the oceans. Here, uncertainty means it could be a lot more or a little less.

Why are scientists not certain about how much the sea level will rise? Because there are processes that are occurring that have the potential for causing huge sea level rise, but we’re uncertain about how fast they will occur. Specifically, two very large sheets of ice sit atop Greenland and Antarctica. If those sheets melt, sea levels will rise hundreds of feet.

Parts of the ice sheets are melting, but how much will melt and how fast will the melting occur? Are we talking decades? Centuries? Millennia? Scientists really want to know the answer to this question. Not only is it interesting scientifically, but it has huge impacts on coastal planning.

One reason the answer to this question is illusive is that melting of ice sheets can occur from above (warm air and sunlight) or from below (warm ocean waters). In many instances, it’s the melting from below that is most significant – but this melting from below is really hard to measure.

With hope we will have a much clearer sense of ice sheet melting and sea level rise because of a new scientific endeavor that is part of a NASA project – Oceans Melting Greenland (OMG). This project has brought together some of the best oceanographers and ice experts in the world. The preliminary results are encouraging and are discussed in two recent publications here and here.

In the papers, the authors note that Greenland ice loss has increased substantially in recent decades. It now contributes approximately 1/3 to total sea level rise. The authors want to know whether this contribution will change over time and they recognize that underwater processes may be the most important to study. In fact, they note in their paper:

Specifically, our goal is improved understanding of how ocean hydrographic variability around the ice sheet impacts glacial melt rates, thinning and retreat.

In plain English, they want to know how water flow around Greenland affects the ice melt.

Their experiments are measuring a number of key attributes. First, yearly changes in the temperature of ocean water near Greenland. Second, the yearly changes to the glaciers on Greenland that extend into the ocean waters. Third, they are observing marine topography (the shape of the land underneath the ocean surface).

The sea floor shape is quite complicated, particularly near Greenland. Past glaciers carved deep troughs in the sea floor in some areas, allowing warm salty water to reach huge glaciers that are draining the ice sheet. As lead OMG investigator Josh Willis said:

What’s interesting about the waters around Greenland is that they are upside down. Warm, salty water, which is heavy, sits below a layer of cold, fresh water from the Arctic Ocean. That means the warm water is down deep, and glaciers sitting in deep water could be in trouble.

As the warm water attacks marine glaciers (glaciers that extend into the ocean), the ice tends to break and calve, retreating toward land. In some cases, the glaciers retreat until their grounding line coincides with the shore. But in other cases the undulating surface allows warm water to wear the glacier underside for long distances and thereby increase the risk of large calving events.

Oftentimes, when glaciers near the coast break off they uncork other ice that can then more easily flow into the oceans.

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Why uranium persists in groundwater at former mining sites

March 9, 2017

This cycling in the aquifer may result in the persistent plumes of uranium contamination found in groundwater, something that wasn’t captured by earlier modeling efforts.

Study helps explain why uranium persists in groundwater at former mining sites      https://www.sciencedaily.com/releases/2017/02/170202163234.htm

February 2, 2017

Source:
SLAC National Accelerator Laboratory
Summary:
A recent study helps describe how uranium cycles through the environment at former uranium mining sites and why it can be difficult to remove.

Decades after a uranium mine is shuttered, the radioactive element can still persist in groundwater at the site, despite cleanup efforts.

A recent study led by scientists at the Department of Energy’s SLAC National Accelerator Laboratory helps describe how the contaminant cycles through the environment at former uranium mining sites and why it can be difficult to remove. Contrary to assumptions that have been used for modeling uranium behavior, researchers found the contaminant binds to organic matter in sediments. The findings provide more accurate information for monitoring and remediation at the sites.

The results were published in the Proceedings of the National Academy of Sciences.

In 2014, researchers at SLAC’s Stanford Synchrotron Radiation Lightsource (SSRL) began collaborating with the DOE Office of Legacy Management, which handles contaminated sites associated with the legacy of DOE’s nuclear energy and weapons production activities. Through projects associated with the Uranium Mill Tailings Radiation Control Act, the DOE remediated 22 sites in Colorado, Wyoming and New Mexico where uranium had been extracted and processed during the 1940s to 1970s.

Uranium was removed from the sites as part of the cleanup process, and the former mines and waste piles were capped more than two decades ago. Remaining uranium deep in the subsurface under the capped waste piles was expected to leave these sites due to natural groundwater flow. However, uranium has persisted at elevated levels in nearby groundwater much longer than predicted by scientific modeling………

“For the most part, uranium contamination has only been looked at in very simple model systems in laboratories,” Bone says. “One big advancement is that we are now looking at uranium in its native environmental form in sediments. These dynamics are complicated, and this research will allow us to make field-relevant modeling predictions.”In an earlier study, the SLAC team discovered that uranium accumulates in the low-oxygen sediments near one of the waste sites in the upper Colorado River basin. These deposits contain high levels of organic matter — such as plant debris and bacterial communities.During this latest study, the researchers found the dominant form of uranium in the sediments, known as tetravalent uranium, binds to organic matter and clays in the sediments. This makes it more likely to persist at the sites. The result conflicted with current models used to predict movement and longevity of uranium in sediments, which assumed that it formed an insoluble mineral called uraninite.

Different chemical forms of the element vary widely in how mobile they are — how readily they move around — in water, says Sharon Bone, lead author on the paper and a postdoctoral researcher at SSRL, a DOE Office of Science User Facility.

Since the uranium is bound to organic matter in sediments, it is immobile under certain conditions. Tetravalent uranium may become mobile when the water table drops and oxygen from the air enters spaces in the sediment that were formerly filled with water, particularly if the uranium is bound to organic matter in sediments rather than being stored in insoluble minerals.

“Either you want the uranium to be soluble and completely flushed out by the groundwater, or you just want the uranium to remain in the sediments and stay out of the groundwater,” Bone says. “But under fluctuating seasonal conditions, neither happens completely.”

This cycling in the aquifer may result in the persistent plumes of uranium contamination found in groundwater, something that wasn’t captured by earlier modeling efforts.