Archive for the ‘– oceans’ Category

The effects of radioactive waste water released into the ocean

June 17, 2021

when radionuclides are present in seawater alongside commonly-occurring metals like copper, the DNA damage caused by radionuclides to the mussels was increased.

the need for transparency when it comes to nuclear technology has never been greater

After all, we are what we eat: our health as a global community depends on the health of the environment, and a contaminated ocean knows no geographical or political borders.

Nuclear power: how might radioactive waste water affect the environment? https://theconversation.com/nuclear-power-how-might-radioactive-waste-water-affect-the-environment-159483   Awadhesh Jha
Professor of Genetic Toxicology and Ecotoxicology, University of Plymouth     April 30, 2021
 It’s been just over a decade since the fourth most powerful earthquake of the modern era triggered a tsunami that struck Fukushima on the eastern coastline of Japan, causing thousands of deaths and leaving hundreds of thousands unable to return home. That tsunami was also responsible for the world’s worst nuclear accident since the Chernobyl disaster.

When the 14-metre wave flooded the Fukushima Daiichi plant, it shut down emergency generators, triggering a series of heat-induced meltdowns.Now, the Japanese government’s decision to allow the release of more than one million tonnes of radioactive water from the plant into the ocean has dividedopinion.

Water is a vital tool for all nuclear power stations: it’s used to cool their heat-generating radioactive cores. During the cooling process, the water becomes contaminated with radionuclides – unstable atoms with excess energy – and must be filtered to remove as many radionuclides as possible.

The filtered water is then stored in huge steel tanks or released into nearby bodies of water. As huge amounts of water are required by every plant, most nuclear facilities are built on coastlines – or, in the case of Chernobyl, surrounded by huge lakes. That way, filtered waste water can be discharged into the ocean or lake once it’s been assessed and confirmed safe by authorities.

This is how workers at Fukushima dealt with waste water while the plant was operating. But since the tsunami hit in 2011, authorities have used more than a million tonnes of water to try and cool the plant’s disabled reactors, which are still hot thanks to the long-term release of energy from the nuclear power source. All that radioactive water – which is more contaminated than standard waste water – has to go somewhere. The decision to release it into the oceans is – some would argue – the most pragmatic long-term solution.

What could the impacts be?

The process of filtering and diluting the huge amounts of water to meet safety standards will take a few years to complete. Then, we’d usually expect the water to be released gradually in small volumes through coastal pipelines. That way, any potential effects of releasing the radioactive waste will be minimised. However, the fact is that we don’t know exactly what those effects will be on marine – or human – life, given the sheer volume of water set to be released from the Fukushima plant.

Our own research has shown that a number of marine species could have their DNA damaged through extended exposure to radionuclides in seawater. It’s important to note that our conclusions are mostly drawn from studies in the lab, rather than in the real world; when a nuclear accident takes place, human safety takes priority and biological assessment often takes place decades after the original event.

That being said, our experiments with both marine and freshwater mussels found that when radionuclides are present in seawater alongside commonly-occurring metals like copper, the DNA damage caused by radionuclides to the mussels was increased. Much, much more research is needed to understand the effects of exposure to different types of radionuclides on different species.

In the meantime, anger towards Japan’s decision from fishing communities is understandable. In a world where global dependence on fisheries for food is increasing – and at least 10% of the world’s population depend on fisheries for their livelihood – a potentially contaminated environment could result in a contaminated food chain, raising consumer concerns.

We also know that around 95% of cancers in humans are triggered by exposure to toxic substances present in the environment, food included. If these substances damage genetic material within our cells, that damage must be repaired. Otherwise, the damaged cell either dies or divides. And when the latter happens, the damage – which can cause genetic mutations – is passed on to dividing cells in a process that may lead to diseases like cancer.

If that genetic damage happens to egg or sperm cells, it may be passed down from parent to child, triggering new diseases in future generations. To neutralise these complex threats, it’s key to ensure that only safe levels of nuclear waste are being released into the ocean.

Where do we go from here?

As new nuclear plants emerge in the effort to tackle climate change, the need for transparency when it comes to nuclear technology has never been greater: especially if we are to build public confidence in the benefits of nuclear energy.

When nuclear reactors are mentioned, it’s disasters which tend to spring to mind. Yet considering the long history of nuclear power generation, serious accidents – involving loss of life and severe damage to the environment – are extraordinarily rare. The huge amounts of data gathered from each disaster site have enabled powerful advances in nuclear security, making future accidents even less likely. Meanwhile, waste from the world’s nuclear reactors is being managed safely every day, although long-term solutions to waste disposal still pose a challenge.

Rapidly developing technology like nuclear fusion – mimicking the Sun’s way of generating energy by fusing hydrogen atoms to form helium, and converting that helium into energy – may eventually slash generation of nuclear waste. There’s also room for improvement of our existing nuclear facilities to help minimise waste generation: for example, by forcing radioactive byproducts to decay faster.

But while we still rely on nuclear power, the most urgent priority is to set internationally accepted regulations for radiation exposure levels across different species. After all, we are what we eat: our health as a global community depends on the health of the environment, and a contaminated ocean knows no geographical or political borders.

14 million tonnes of plastic on ocean floor – more on the coasts

November 28, 2020
A confronting amount’: CSIRO study finds 14 million tonnes of plastic on ocean floorhttps://thenewdaily.com.au/news/national/2020/10/05/micro-plastics-ocean-floor/   Samantha Dick
Every drink bottle we buy, face scrub we use and chip packet we finish results in tiny plastics entering the ocean.But where are these tiny micro-plastics, exactly?Are they floating around on the ocean’s surface, waiting to be scooped up by a surfer?

Or are they stuck in the tummies of turtles or seabirds?

A new study by the CSIRO, Australia’s national science agency, has estimated up to 14 million tonnes of micro-plastics have sunk to the bottom of the ocean floor.

The peer-reviewed research, published on Tuesday, is the first global estimate for micro-plastics on the seafloor.    Dr Britta Denise Hardesty, team leader with CSIRO’s Oceans and Atmosphere, said 14 million tonnes of micro-plastics was a “huge amount, especially when you think about how tiny all those bits are”.Dr Britta Denise Hardesty, team leader with CSIRO’s Oceans and Atmosphere, said 14 million tonnes of micro-plastics was a “huge amount, especially when you think about how tiny all those bits are”.

Every drink bottle we buy, face scrub we use and chip packet we finish results in tiny plastics entering the ocean.

But where are these tiny micro-plastics, exactly?
Are they floating around on the ocean’s surface, waiting to be scooped up by a surfer?

Or are they stuck in the tummies of turtles or seabirds?

A new study by the CSIRO, Australia’s national science agency, has estimated up to 14 million tonnes of micro-plastics have sunk to the bottom of the ocean floor.

The peer-reviewed research, published on Tuesday, is the first global estimate for micro-plastics on the seafloor.

Dr Britta Denise Hardesty, team leader with CSIRO’s Oceans and Atmosphere, said 14 million tonnes of micro-plastics was a “huge amount, especially when you think about how tiny all those bits are”.

To put it into perspective: Imagine five carrier bags stuffed with plastic dotted along every single metre of coastline around the world, excluding Antarctica

The piles of bags would sit on every Australian beach, along Italy’s Amalfi Coast, around Vietnam’s Ha Long Bay, and all around Canada’s coastlines and beyond.

Now imagine someone pushing those bags into the ocean, and letting them sink into the darkness.

“It’s a confronting amount, and hopefully it provides a reasonable wake-up call,” Dr Hardesty told The New Daily.

“We’re finding them hundreds of kilometres offshore and thousands of metres deep – more micro-plastics than has been found by lots of other studies.”

“Micro-plastics come from the same place as plastics,” Dr Hardesty said, adding “micro just means they’re smaller than 5mm”.

“It’s really just small plastic from single-use items, consumer goods, industry or fishing-related goods, cosmetics, micro-beads, agriculture, aquaculture, household waste, everything.”Many of these tiny plastics end up in our oceans via stormwater drains, sewage systems, sea-based activities, littering, things falling off the backs of trucks, and improper waste management where people intentionally dump rubbish straight into the sea or rivers.

They often end up in the stomachs of marine animals like dolphins or fish, while bigger pieces of plastic can be just as dangerous.

“Masks that have those little straps can tangle the feet and legs of sea birds and things like that,” Dr Hardesty said.

“Rubber gloves might be more likely to look like a jellyfish that could be mistakenly eaten by turtles if they end up in the ocean.”

The World Economic Forum estimates one garbage truck of plastic alone is dumped into the ocean every minute of every day.

It estimates there could be more plastic in the ocean than fish by 2050.

The missing piece

Although the CSIRO’s findings are troubling, perhaps what’s more concerning is the answer to the following question: Where is the rest of the missing plastic?

Compared to the tonnes of plastic entering the ocean every day, Dr Hardesty said 14 million tonnes on the ocean floor was “just a drop in the ocean”.

“Where is all the missing plastic? Is it in the stomachs of animals? Is it floating on the surface?” she said.

“I’d say most of it is on our coastlines.”

Climate change and the loss of sea otters

November 28, 2020

Loss of sea otters accelerating the effects of climate change, New research published in Science reveals that the influence of a key predator governs the pace of climate impacts on Alaskan reefs  EurekAlert, BIGELOW LABORATORY FOR OCEAN SCIENCES , 13 Sept 20,  The impacts of predator loss and climate change are combining to devastate living reefs that have defined Alaskan kelp forests for centuries, according to new research published in Science.

“We discovered that massive limestone reefs built by algae underpin the Aleutian Islands’ kelp forest ecosystem,” said Douglas Rasher, a senior research scientist at Bigelow Laboratory for Ocean Sciences and the lead author of the study. “However, these long-lived reefs are now disappearing before our eyes, and we’re looking at a collapse likely on the order of decades rather than centuries.”

The coral-like reefs, built by the red alga Clathromorphum nereostratum, are being ground down by sea urchins. Sea urchins exploded in number after their predator, the Aleutian sea otter, became functionally extinct in the 1990’s. Without the urchins’ natural predator to keep them in check, urchins have transformed the seascape – first by mowing down the dense kelp forests, and now by turning their attention to the coralline algae that form the reef.

Clathromorphum produces a limestone skeleton that protects the organism from grazers and, over hundreds of years, forms a complex reef that nurtures a rich diversity of sea life. With kelp gone from the menu, urchins are now boring through the alga’s tough protective layer to eat the alga – a process that has become much easier due to climate change.

“Ocean warming and acidification are making it difficult for calcifying organisms to produce their shells, or in this case, the alga’s protective skeleton,” said Rasher, who led the international team of researchers that included coauthors Jim Estes from UC Santa Cruz and Bob Steneck from University of Maine. “This critical species has now become highly vulnerable to urchin grazing – right as urchin abundance is peaking. It’s a devasting combination.”………..

The results of the experiment confirmed that climate change has recently allowed urchins to breach the alga’s defenses, pushing this system beyond a critical tipping point.

“It’s well documented that humans are changing Earth’s ecosystems by altering the climate and by removing large predators, but scientists rarely study those processes together,” Rasher said. “If we had only studied the effects of climate change on Clathromorphum in the laboratory, we would have arrived at very different conclusions about the vulnerability and future of this species. Our study shows that we must view climate change through an ecological lens, or we’re likely to face many surprises in the coming years.”……..https://www.eurekalert.org/pub_releases/2020-09/blfo-los090420.php

THe Arctic’s slow-moving underwater nuclear disaster – Russia’s radioactive trash

November 28, 2020
Russia’s ‘slow-motion Chernobyl’ at sea, BBC  By Alec Luhn2nd September 2020,   ”…………………………. Beneath some of the world’s busiest fisheries, radioactive submarines from the Soviet era lie disintegrating on the seafloor. Decades later, Russia is preparing to retrieve them……….

 With a draft decree published in March, President Vladimir Putin set in motion an initiative to lift two Soviet nuclear submarines and four reactor compartments from the silty bottom, reducing the amount of radioactive material in the Arctic Ocean by 90%. First on the list is Lappa’s K-159.

The two nuclear submarines together contain one million curies of radiation, or about a quarter of that released in the first month of the Fukushima disaster

The message, which comes before Russia’s turn to chair the Arctic Council next year, seems to be that the country is not only the preeminent commercial and military power in the warming Arctic, but also a steward of the environment. The K-159 lies just outside of Murmansk in the Barents Sea, the richest cod fishery in the world and also an important habitat of  haddock, red king crab, walruses, whales, polar bears and many other animals.

Russia facing huge problem to recover radioactive sunken nuclear reactors, but Putin still plans new ones in the Arctic

November 28, 2020

Russia’s ‘slow-motion Chernobyl’ at sea, FUTURE PLANET | OCEANS By Alec Luhn, 2nd September 2020 ……….

Minimising risk

Russia, Norway and other countries whose fishing boats ply the bountiful waters of the Barents Sea have now found themselves with a sword of Damocles hanging over their heads. Although a 2014 Russian-Norwegian expedition to the K-159 wreck that tested the water, seafloor and animals like a sea centipede did not find radiation above background levels, an expert from Moscow’s Kurchatov Institute said at the time that a reactor containment failure “could happen within 30 years of sinking in the best case and within 10 years at the worst”. That would release radioactive caesium-137 and strontium-90, among other isotopes.

While the vast size of the oceans quickly dilutes radiation, even very small levels can become concentrated in animals at the top of the food chain through “bioaccumulation” – and then be ingested by humans. But economic consequences for the Barents Sea fishing industry, which provides the vast majority of cod and haddock at British fish and chip shops, “may perhaps be worse than the environmental consequences”, says Hilde Elise Heldal, a scientist at Norway’s Institute of Marine Research.

According to her studies, if all the radioactive material from the K-159’s reactors were to be released in a single “pulse discharge”, it would increase Cesium-137 levels in the muscles of cod in the eastern Barents Sea at least 100 times. (As would a leak from the Komsomolets, another sunken Soviet submarine near Norway that is not slated for lifting.) That would still be below limits set by the Norwegian government after the Chernobyl accident, but it could be enough to scare off consumers. More than 20 countries continue to ban Japanese seafood, for instance, even though studies have failed to find dangerous concentrations of radioactive isotopes in Pacific predatory fishes following the Fukushima nuclear power plant release in 2011. Any ban on fishing in the Barents and Kara seas could cost the Russian and Norwegian economies €120m ($140m; £110m) a month, according to a European Commission feasibility study about the lifting project.

There is no ship in the world capable of lifting the K-159, so a special salvage vessel would have to be built

But an accident while raising the submarine, on the other hand, could suddenly jar the reactor, potentially mixing fuel elements and starting an uncontrolled chain reaction and explosion. That could boost radiation levels in fish 1,000 times normal or, if it occurred on the surface, irradiate terrestrial animals and humans, another Norwegian study found. Norway would be forced to stop sales of products from the Arctic such as fish and reindeer meat for a year or more. The study estimated that more radiation could be released than in the 1985 Chazhma Bay incident, when an uncontrolled chain reaction during refuelling of a Soviet submarine near Vladivostok killed 10 sailors.

Amundsen argued that the risk of such a criticality excursion with the K-159 or K-27 was low and could be minimised with proper planning, as it was during the removal of high-risk spent fuel from Andreyev Bay.

“In that case we do not leave the problem for future generations to solve, generations where the knowledge of handling such legacy waste may be very limited,” he says.

The safety and transparency of Russia’s nuclear industry has often been questioned, though, most recently when Dutch authorities concluded that radioactive iodine-131 detected over northern Europe in June originated in western Russia. The Mayak reprocessing facility that received the spent fuel from Andreyev Bay by train has a troubled history going back to the world’s then-worst nuclear disaster in 1957. Rosatom continues to deny the findings of international experts that the facility was the source of a radioactive cloud of ruthenium-106 registered over Europe in 2017.

While the K-159 and K-27 need to be raised, Rashid Alimov of Greenpeace Russia has reservations. “We are worried about the monitoring of this work, public participation and the transport [of spent fuel] to Mayak,” he says.

Custom mission

Raising a submarine is a rare feat of engineering. The United States spent $800m (£610m) in an attempt to lift another Soviet submarine, the diesel-powered K-129 that carried several nuclear missiles, from 16,400ft (5,000m) in the Pacific Ocean, under the guise of a seabed mining operation. In the end, they only managed to bring a third of the submarine to the surface, leaving the CIA with little usable intelligence.

That was the deepest raise in history. The heaviest was the Kursk. To bring the latter 17,000-tonne missile submarine up from 350ft (108m) below the Barents Sea, the Dutch companies Mammoet and Smit International installed 26 hydraulically cushioned lifting jacks on a giant barge and cut 26 holes in the submarine’s rubber-coated steel hull with a water jet operated by scuba divers. On 8 October 2001, rushing to beat the winter storm season after four months of nerve-wracking work and delays, steel grippers fitted in the 26 holes lifted the Kursk from the seabed in 14 hours, after which the barge was towed to a dry dock in Murmansk.

At less than 5,000 tonnes, the K-159 is smaller than the Kursk, but even before it sank its outer hull was “as weak as foil”, according to Bellona. It has since been embedded in 17 years’ worth of silt. A hole in the bow would seem to rule out pumping it full of air and raising it with balloons, as has been previously suggested. At a conference of European Bank of Reconstruction and Development donors in December, a Rosatom representative said there was no ship in the world capable of lifting it, so a special salvage vessel would have to be built.

That will increase the estimated cost of €278m ($330m; £250m) to raise the six most radioactive objects. Donors are discussing Russia’s request to help finance the project, said Balthasar Lindauer, director of nuclear safety at EBRD.

“There’s consensus something needs to be done there,” he says. Any such custom-built vessel would likely need a bevy of specialised technologies such as bow and aft thrusters to keep it positioned precisely over the wreck.

But in August, Grigoriev told a Rosatom-funded website that one plan the company was considering would involve a pair of barges fitted with hydraulic cable jacks and secured to deep-sea moorings. Instead of steel grippers like the ones inserted into the holes in the Kursk, giant curved pincers would grab the entire hull and lift it up between the barges. A partially submersible scow would be positioned underneath, then brought to the surface along with the submarine and finally towed to port. The K-27 and K-159 could both be recovered this way, he said.

One of three engineering firms working on proposals for Rosatom is the military design bureau Malachite, which drafted a project to raise the K-159 in 2007 that “was never realised due to a lack of money”, according to its lead designer. This year the bureau has begun updating this plan, an employee tells Future Planet in the lobby of Malachite’s headquarters in St Petersburg. Many questions remain, however.

“What condition is the hull in? How much of force can it handle? How much silt has built up? We need to survey the conditions there,” the employee says, before the head of security arrives to break up our conversation.

Nuclear paradox

Removing the six radioactive objects fits in with an image Putin as crafted as a defender of the fragile Arctic environment. In 2017, he inspected the results of an operation to remove 42,000 tonnes of scrap metal from the Franz Josef Land archipelago as part of a “general clean-up of the Arctic”. He has spoken about environmental preservation at an annual conference for Arctic nations. And on the same day in March 2020 that he issued his draft decree about the sunken objects, he signed an Arctic policy that lists “protecting the Arctic environment and the native lands and traditional livelihood of indigenous peoples” as one of six national interests in the region.

“For Putin, the Arctic is part of his historic legacy. It should be well-protected, bring real benefits and be clean,” said Dmitry Trenin, head of the think tank Carnegie Centre Moscow.

Yet while pursuing a “clean” Arctic, the Kremlin has also been backing Arctic oil and gas development, which accounts for the majority of shipping on the Northern Sea Route. State-owned Gazprom built one of two growing oil and gas clusters on the Yamal peninsula, and this year the government cut taxes on new Arctic liquified natural gas projects to 0% to tap into some of the trillions of dollars of fossil fuel and mineral wealth in the region.

And even as Putin cleans up the Soviet nuclear legacy in the far north, he is building a nuclear legacy of his own. A steady march of new nuclear icebreakers and, in 2019, the world’s only floating nuclear power plant has again made the Arctic the most nuclear waters on the planet.

Meanwhile, the Northern Fleet is building at least eight submarines and has plans to construct several more, as well as eight missile destroyers and an aircraft carrier, all of them nuclear-powered. It has also been testing a nuclear-powered underwater drone and cruise missile. In total, there could be as many as 114 nuclear reactors in operation in the Arctic by 2035, almost twice as many as today, a 2019 Barents Observer study found.

This growth has not gone without incident. In July 2019, a fire on a nuclear deep-sea submersible near Murmansk almost caused a “catastrophe of a global scale,” an officer reportedly said at the funeral of the 14 sailors killed. The next month, a “liquid-fuel reactive propulsion system” exploded during a test on a floating platform in the White Sea, killing two of those involved and briefly spiking radiation levels in the nearby city of Severodvinsk.

“The joint efforts of the international community including Norway and Russia after breakup of the Soviet Union, using taxpayer money to clean up nuclear waste, was a good investment in our fisheries,” says The Barents Observer’s Nilsen. “But today there are more and more politicians in Norway and Europe who think it’s a really big paradox that the international community is giving aid to secure the Cold War legacy while it seems Russia is giving priority to building a new Cold War.”

As long as the civilian agency Rosatom is tasked with clean-up, the Russian military has little incentive to slow down this nuclear spree, Nilsen notes.

“Who is going to pay for the clean-up of those reactors when they are not in use anymore?” he asks. “That is the challenge with today’s Russia, that the military don’t have to think what to do with the very, very expensive decommissioning of all this.”

So while the coming nuclear clean-up is set to be the largest of its kind in history, it may turn out to be just a prelude to what’s needed to deal with the next wave of nuclear power in the Arctic…………….https://www.bbc.com/future/article/20200901-the-radioactive-risk-of-sunken-nuclear-soviet-submarines

Ice melting at a surprisingly fast rate underneath Shirase Glacier Tongue in East Antarctica

November 28, 2020
East Antarctic melting hotspot identified
  https://www.sciencedaily.com/releases/2020/08/200824092000.htm
        August 24, 2020
Source:
Hokkaido University
Summary:
Ice is melting at a surprisingly fast rate underneath Shirase Glacier Tongue in East Antarctica due to the continuing influx of warm seawater into the Lützow-Holm Bay.

Hokkaido University scientists have identified an atypical hotspot of sub-glacier melting in East Antarctica. Their findings, published in the journal Nature Communications, could further understandings and predictions of sea level rise caused by mass loss of ice sheets from the southernmost continent.

The 58th Japanese Antarctic Research Expedition had a very rare opportunity to conduct ship-based observations near the tip of East Antarctic Shirase Glacier when large areas of heavy sea ice broke up, giving them access to the frozen Lützow-Holm Bay into which the glacier protrudes.

“Our data suggests that the ice directly beneath the Shirase Glacier Tongue is melting at a rate of 7-16 meters per year,” says Assistant Professor Daisuke Hirano of Hokkaido University’s Institute of Low Temperature Science. “This is equal to or perhaps even surpasses the melting rate underneath the Totten Ice Shelf, which was thought to be experiencing the highest melting rate in East Antarctica, at a rate of 10-11 meters per year.”

The Antarctic ice sheet, most of which is in East Antarctica, is Earth’s largest freshwater reservoir. If it all melts, it could lead to a 60-meter rise in global sea levels. Current predictions estimate global sea levels will rise one meter by 2100 and more than 15 meters by 2500. Thus, it is very important for scientists to have a clear understanding of how Antarctic continental ice is melting, and to more accurately predict sea level fluctuations.

Most studies of ocean-ice interaction have been conducted on the ice shelves in West Antarctica. Ice shelves in East Antarctica have received much less attention, because it has been thought that the water cavities underneath most of them are cold, protecting them from melting.

During the research expedition, Daisuke Hirano and collaborators collected data on water temperature, salinity and oxygen levels from 31 points in the area between January and February 2017. They combined this information with data on the area’s currents and wind, ice radar measurements, and computer modelling to understand ocean circulation underneath the Shirase Glacier Tongue at the glacier’s inland base.

The scientists’ data suggests the melting is occurring as a result of deep, warm water flowing inwards towards the base of the Shirase Glacier Tongue. The warm water moves along a deep underwater ocean trough and then flows upwards along the tongue’s base, warming and melting the ice. The warm waters carrying the melted ice then flow outwards, mixing with the glacial meltwater.

The team found this melting occurs year-round, but is affected by easterly, alongshore winds that vary seasonally. When the winds diminish in the summer, the influx of the deep warm water increases, speeding up the melting rate.

“We plan to incorporate this and future data into our computer models, which will help us develop more accurate predictions of sea level fluctuations and climate change,” says Daisuke Hirano.

Lower-latitude oceans drive complex changes in the Arctic Ocean,

August 21, 2020
Arctic Ocean changes driven by sub-Arctic seas   https://www.eurekalert.org/pub_releases/2020-07/uoaf-aoc071020.php  b  UNIVERSITY OF ALASKA FAIRBANK  New research explores how lower-latitude oceans drive complex changes in the Arctic Ocean, pushing the region into a new reality distinct from the 20th-century norm.

The University of Alaska Fairbanks and Finnish Meteorological Institute led the international effort, which included researchers from six countries. The first of several related papers was published this month in Frontiers in Marine Science.

Climate change is most pronounced in the Arctic. The Arctic Ocean, which covers less than 3% of the Earth’s surface, appears to be quite sensitive to abnormal conditions in lower-latitude oceans.

“With this in mind, the goal of our research was to illustrate the part of Arctic climate change driven by anomalous [different from the norm] influxes of oceanic water from the Atlantic Ocean and the Pacific Ocean, a process which we refer to as borealization,” said lead author Igor Polyakov, an oceanographer at UAF’s International Arctic Research Center and FMI.

Although the Arctic is often viewed as a single system that is impacted by climate change uniformly, the research stressed that the Arctic’s Amerasian Basin (influenced by Pacific waters) and its Eurasian Basin (influenced by Atlantic waters) tend to differ in their responses to climate change.

Since the first temperature and salinity measurements taken in the late 1800s, scientists have known that cold and relatively fresh water, which is lighter than salty water, floats at the surface of the Arctic Ocean. This fresh layer blocks the warmth of the deeper water from melting sea ice.

In the Eurasian Basin, that is changing. Abnormal influx of warm, salty Atlantic water destabilizes the water column, making it more susceptible to mixing. The cool, fresh protective upper ocean layer is weakening and the ice is becoming vulnerable to heat from deeper in the ocean. As mixing and sea ice decay continues, the process accelerates. The ocean becomes more biologically productive as deeper, nutrient-rich water reaches the surface.

By contrast, increased influx of warm, relatively fresh Pacific water and local processes like sea ice melt and accumulation of river water make the separation between the surface and deep layers more pronounced on the Amerasian side of the Arctic. As the pool of fresh water grows, it limits mixing and the movement of nutrients to the surface, potentially making the region less biologically productive.

The study also explores how these physical changes impact other components of the Arctic system, including chemical composition and biological communities.

Retreating sea ice allows more light to penetrate into the ocean. Changes in circulation patterns and water column structure control availability of nutrients. In some regions, organisms at the base of the food web are becoming more productive. Many marine organisms from sub-Arctic latitudes are moving north, in some cases replacing the local Arctic species.

“In many respects, the Arctic Ocean now looks like a new ocean,” said Polyakov.

These differences change our ability to predict weather, currents and the behavior of sea ice. There are major implications for Arctic residents, fisheries, tourism and navigation.

This study focused on rather large-scale changes in the Arctic Ocean, and its findings do not necessarily represent conditions in nearshore waters where people live and hunt.

The study stressed the importance of future scientific monitoring to understand how this new realm affects links between the ocean, ice and atmosphere.

###

Co-authors of the paper include Matthew Alkire, Bodil Bluhm, Kristina Brown, Eddy Carmack, Melissa Chierici, Seth Danielson, Ingrid Ellingsen, Elizaveta Ershova, Katarina Gårdfeldt, Randi Ingvaldsen, Andrey V. Pnyushkov, Dag Slagstad and Paul Wassmann.

Ignoring the danger of ionising radiation: nuclear waste dumping in the sea

March 31, 2018

The idea that nuclear pollution can be rendered safe by extreme dilution has been proven wrong

radioactive materials bioaccumulate. A worm can contain 2,000 to 3,000 times higher levels than its environment. The worm is then eaten by another marine animal, which gets eating by another, and so on. At each step, the radioactive level rises. Barbey has identified reproductive defects in sea crabs, caused by radioactive contamination, and these genetic defects are passed on to future generations of crabs.

Are we to believe the same is not happening in humans, who are at the top of the food chain?

The fact of the matter is that a certain number of cancer deaths are considered acceptable in order to keep costs for the nuclear waste industry down. The question no one has the answer to is: At what point do the deaths begin to outweigh the cost-savings of the nuclear industry?

As to where such cost-benefit considerations came from in the first place, the filmmakers identify the International Commission on Radiological Protection (ICRP)

the nuclear industry is hardly operating for the benefit of the many.

The Rarely Discussed Reality of Radioactive Pollution https://articles.mercola.com/sites/articles/archive/2017/10/07/radioactive-pollution-exposure.aspx?utm_source=dnl&utm_medium=email&utm_content=art1&utm_campaign=20171007Z1_UCM&et_cid=DM16

Story at-a-glance

  • For decades, the common method of nuclear disposal was to dump plutonium-filled steel barrels into the ocean. Today, many if not most of these barrels have corroded and disintegrated, releasing radioactive material into the environment
  • “Versenkt und Vergessen” (Sunk and Forgotten) investigates what happened to the barrels of nuclear waste, and how radioactive material is disposed of today
  • In 1993, nuclear waste dumping into the ocean was banned worldwide, yet the ocean remains a primary dumping ground for radioactive waste
  • Instead of ditching barrels overboard, the nuclear waste industry built pipes along the bottom of the sea, through which the radioactive material is discharged directly into the open sea
  • Cancer deaths are considered acceptable to keep costs for the nuclear waste industry down. According to the International Commission on Radiological Protection, this cost-benefit consideration is part of Epicurus’ utilitarian ethics, which states that the needs of the many outweigh the needs of the few

By Dr. Mercola

A rarely addressed environmental problem is radioactive pollution from nuclear waste disposal. For decades, the common method of nuclear disposal was to simply dump plutonium-filled steel barrels into the ocean.

Starting with an overview of the past, the featured documentary, “Versenkt und Vergessen,” (Sunk and Forgotten), notes that in May 1967, 100,000 tons of nuclear waste from Germany, Great Britain and France were dumped in the North Atlantic, the Irish Sea and the English Channel. And that was just one of many loads.

Officials claimed the waste would be safely diluted at depths of about 4,000 meters (2.5 miles). The motto was: “The solution to pollution is dilution.” But was it? The film crew investigates what happened to these barrels of nuclear waste, and how radioactive material is disposed of today, now that ocean dumping is no longer allowed.

1970s Activism Raised Awareness but Could Not Stop Nuclear Dumping

Greenpeace began raising public awareness about the practice of dumping nuclear waste in the ocean during the 1970s. Alas, the nuclear industry remained unfazed. Instead, environmentalists were attacked and criminalized. John Large, a nuclear physicist who was involved in the development of a British nuclear bomb in the 1960s, knows a thing or two about nuclear dumping.

In addition to barrels filled with plutonium, nuclear reactor fuel rods were also routinely dumped into the ocean. And, while specific sites had been chosen for the disposal, there are no guarantees the rods or barrels actually made it there.

The reason for this is because the ship’s crew were continually exposed to radioactivity as long as the rods remained onboard. This meant the captain had to pay careful attention to exposure times to protect the health of the crew, and if they ran into bad weather, the cargo would have to be dumped wherever they happened to be when the clock ran out.

Dumping Inventory Records Tell Us Little

In addition to that, many entries in the disposal inventory records simply read, “not known,” when it comes to the amount, content or location of the disposal. With such an apparent lack of precision in the dumping inventory records, how might the fate of the barrels and fuel rods be ascertained?

The filmmakers turn to the British Health Protection Agency (HPA), which is responsible for radioactive waste. Alas, they have little choice but to rely on the information they’re given, no matter how incomplete. Michael Meacher MP, who was Minister for the Environment between 1997 and 2003 and an opponent of the nuclear dumping policy, believes the lack of record keeping is no accident.

He suggests it was probably an agreement between the British ministry of defense, the Army and the nuclear industry — none of which really wanted anyone to know how much was dumped, what kind of materials were disposed of or exactly where. The less information anyone has, the lower the chances of any of them being held responsible. “This is a sort of conspiracy,” Meacher says, adding that the long-term effects of dumping radioactive waste into oceans are entirely unknown.

Fundamental Assumptions Proven Wrong

The idea that nuclear pollution can be rendered safe by extreme dilution has been proven wrong. As noted by Large, “The fundamental underlying problem was that they assumed that if you dilute the radioactivity with tons and tons of water, it’s safe to discharge. And that has been proven wrong time and time again.” Evidence of this was collected by a German research group in the mid-‘80s.

The exploratory group visited nuclear dumping sites in the Atlantic where they retrieved several barrels, and found plutonium in the water, seabed and fish. An internal document titled “Position paper on the implications of deep sea disposal of radioactive waste,” issued by the International Atomic Energy Agency (IAEA), notes that “Increased concentrations of plutonium in the dump sites indicates plutonium leaks from the barrels.”

Now these toxins have dispersed into the biosphere, and dispersion does not equate to safety. At its headquarters in Monaco, IAEA scientists are conducting experiments to assess the impact of radioactive waste on marine life by feeding marine animals with contaminated food sources. The IAEA, which continuously monitors the ocean floor, claims it has not found any other dumped barrels. The assumption, therefore, is that the barrels ditched in the English Channel have all disintegrated.

Nuclear Waste in the English Channel

There have been no additional investigations at the dumpsites since, however, so is the IAEA correct in its assumption that all dumped barrels have corroded and no longer retrievable? The film crew decides to conduct its own investigation, and travels to an area called Hurd Deep, located in the English Channel near the island of Alderney, where 28,000 barrels of radioactive waste and munitions is known to have been deposited at a depth of 100 meters (328 feet) or less.

With the use of a small unmanned submarine, the team surveils the area. What do they find? On the very first dive, the camera-equipped submersible documents a still undamaged barrel, which could potentially be salvaged. On the second dive, a thoroughly corroded and disintegrating barrel is found — barely half an hour’s boat ride from the coast of France.

With nuclear waste dumped so close to land, what effects might it have on the environment and residents? The team follows professor Chris Busby to Alderney, where a doctor has reported an unusually high number of cancer cases and deaths. Unfortunately, exact statistics on cancer deaths cannot be obtained due to data protection protocols.

Based on informal inquiries, however, the team finds that the island, which has a total of just 2,400 residents, has had quite a few cancer-related deaths. The government, however, assures Busby that everything is fine, and that levels of radioactivity in the environment are far too low to cause harm. According to the IAEA, the dilution hypothesis does work, and despite very large amounts of radioactive waste having been deposited in some areas, the water would still meet safe drinking water standards, were it not saltwater.

Busby disagrees, as does Claus Grupen, a nuclear physicist at the University of Siegen in Germany, who says, “If the amount in which [the radioactive waste] is diluted is infinitely vast — if I discharge it into outer space — then it might be well-diluted. But the Earth is a very small body, and the concentration is growing.” The conclusion is that the radiation is merely spreading out. It’s not actually “disappearing” at all, and according to Busby, every single radionucleotide has the potential to trigger cancer.

Nuclear Ocean Dumping Continues

In 1993, nuclear waste dumping was banned worldwide, in large part thanks to the ongoing efforts of Greenpeace. But that doesn’t mean the practice has stopped. The nuclear industry has merely changed the way it’s doing the dumping. Instead of ditching barrels overboard, the industry built pipes along the bottom of the sea, through which the radioactive material is pumped. To where, you might ask? Directly into the open sea.

One of these nuclear waste pipes is situated in La Hague, Normandy, where physicist David Boilley has founded an environmental group against nuclear ocean dumping. In his view, the nuclear accident in Fukushima has had global ramifications, forcing us to rethink how we view “clean food.” It’s no longer possible to assume that clean water equals clean and healthy fish.

A fish may ultimately be caught in water considered clean, but if that individual fish has, at any point in its life, swum through a contaminated area or eaten contaminated food, it will be contaminated to some degree. So being caught in clean water is no guarantee that it will be free of radioactive contaminants. “It’s like gambling,” Boilley says. “You may be lucky or unlucky.”

Back in Boilley’s lab, water samples prove to have tritium levels that are fivefold higher than those provided by the French nuclear operator Areva. This is why the group, and other environmentalists, refuse to rely on “official” measurements, and insist on taking their own. Fish and shellfish bought at the local market are also tested, as are other marine animals found on the ocean floor.

Microbiologist Pierre Barbey explains that radioactive materials bioaccumulate. A worm can contain 2,000 to 3,000 times higher levels than its environment. The worm is then eaten by another marine animal, which gets eating by another, and so on. At each step, the radioactive level rises. Barbey has identified reproductive defects in sea crabs, caused by radioactive contamination, and these genetic defects are passed on to future generations of crabs.

Are we to believe the same is not happening in humans, who are at the top of the food chain? According to Barbey, the cellular impact is the same. Plutonium has been found in gray seals off the coasts of Europe, and cesium has been found in porpoises. Since the ecosystem is a closed system, every animal must be protected from radioactivity. None is “disposable.” And what happens to the animals will ultimately affect us too.

Why Ocean Dumping Continues Despite Ban

Next, the team visits Sellafield, home of 80 percent of the U.K.’s nuclear waste. This site also has waste pipes dumping radioactive materials into the ocean. In 1997, Greenpeace activists drew attention to the pipe. One of the activists was Shaun Burnie, who to this day continues his fight against the nuclear discharges. He’s particularly concerned about the health and welfare of the locals, especially those who live right on the beach.

Their homes have been found to contain plutonium-contaminated dust, and tests reveal these high-risk individuals have higher levels of radioactivity in their bodies. They even have plutonium in their teeth. Radioactive material originating from Sellafield has also been found along the coast of Norway. But how is it that the nuclear industry can continue disposing of radioactive waste into the ocean when ocean dumping has been banned?

The answer may surprise you. The industry claims the pipes are part of a land-based disposal system, and therefore legal. When asked if there’s a scientific, logical reason why barrels are banned while open discharges into the ocean are allowed, Hartmut Nies with the IAEA replies, “I think it is more of a philosophical question.”

Wolfgang Renneberg, an expert on radioactive waste disposal and director general for nuclear safety in the German Federal Ministry for Environment, Nature Conservation and Nuclear Safety, offers a more definitive answer: There’s only one reason why open discharges are allowed, and that is economics. To install a system to ensure discharges have a near-zero radioactivity would likely be so expensive, it would likely render the plant economically unviable.

Rising Childhood Leukemia Rates Dismissed

So, despite reports of rising rates of leukemia in Sellafield — which, according to Busby are 10 times higher than the rest of the country — the discharges continue. And, since investigations into cancer clusters keep finding the nuclear operation at Sellafield is not a factor, plutonium-contaminated beaches remain open to the public.

Many locals have come to suspect the authorities are being “deliberately imprecise in their work” to hide the extent of the problem. In an area of the beach where official soil testing has not been done, the filmmakers find plutonium levels up to 10 times higher than the permissible limit. Still, some nuclear industry experts insist the dangers associated with radioactive material is small. One 30-year veteran in the industry, Richard Wakeford, says:

“I assess the risk of radiation … to be very small, and should really not be a major [concern] to parents or anyone else. There are much more important things to be worried about. There are two major ideas: Either childhood leukemia is a rare response to a common, but as of yet unidentified, infection, or [it’s due to] large-scale urban, rural population mixing.”

As noted in the film, “Conclusion: Either a virus or population mixing around Sellafield is responsible for cancer — but not the highly toxic nuclear waste from the sea?!” The team turns to another expert, the German physician Klaus Hoffmann, member of a number of German federal radiation protection committees. When asked what he thinks about the U.K’s denial of a link between rising leukemia rates and radioactive pollution, he says:

“They are simply wrong. There is little evidence for the population mixing hypothesis, and there’s absolutely no evidence of the virus hypothesis. There is neither a virus, nor are there antibodies. In other words, forget this whole infection hypothesis. These hypotheses have arisen primarily to explain away any risk from radiation.”     

Industry Cost-Savings Weighed Against Human Life

The fact of the matter is that a certain number of cancer deaths are considered acceptable in order to keep costs for the nuclear waste industry down. The question no one has the answer to is: At what point do the deaths begin to outweigh the cost-savings of the nuclear industry?

As to where such cost-benefit considerations came from in the first place, the filmmakers identify the International Commission on Radiological Protection (ICRP) — an independent charity “established to advance for the public benefit the science of radiological protection, in particular by providing recommendations and guidance on all aspects of protection against ionizing radiation.”

While interview requests with the Commission went unanswered, they discovered a video online in which former ICRP chairman Roger Clarke explains the cost-benefit principle by quoting one of Epicurus’ utilitarian ethics, which states that, “The needs of the many outweigh the needs of the few.”

In this case, you could argue the nuclear industry is hardly operating for the benefit of the many. If the true costs of operations were considered, it would become clear that there are far less expensive, not to mention less toxic, ways to produce energy. As noted in the film, we need safer forms of energy. The waste pipes need to be closed, and any retrievable barrels recovered from the ocean floor and secured. If we do nothing, our environment will continue to deteriorate, and so will human health.

 

The oceans: Russia’s nuclear waste garbage dump

October 30, 2017

Feisty mayor in Russia’s Far East wants his nuclear trash collected http://bellona.org/news/nuclear-issues/2017-09-feisty-mayor-in-russia-far-east-wants-his-nuclear-trash-collected

While lighthouses run on atomic batteries in Russia have become rare, especially along the coasts of the Baltic and Barents Seas, they still have their adherents in the country’s Far East.  by Charles Digges   charles@bellona.no  While lighthouses run on atomic batteries in Russia have become rare, especially along the coasts of the Baltic and Barents Seas, they still have their adherents in the country’s Far East.

A group of radioactivity tracking sleuths on Sakhalin Island in the Pacific say they have hunted down an abandoned generator that ran on strontium-90 sunk off the shores of one of its premier beach resorts.

But that, they say, is just the tip of the iceberg: The discovery lies in the middle of a radioactive graveyard that includes no fewer than 38 sunken vessels containing nuclear waste, and two nuclear warheads that went down when a Soviet bomber crashed near the island’s southern tip in 1976.

Though the Russian Ministry of Defense recently began acknowledging the lost bomber, tracing the origins of the other nuclear cast offs is not so easy.

But at least, says Nikolai Sidirov, mayor of the coastal town of Makarov on Sakhalin’s Bay of Patience, his town knows what this new discovery is – and they want it raised from the depths with the rest of the glowing junk.

Speaking to Novaya Izvestiya, a popular tabloid that morphed out of the official Soviet-era mouthpiece Izvestiya, Sidirov said satellite photos tracking the location of the crashed bomber have turned up something else lurking under the waves: An RTG.

That’s short for Radioisotope Thermoelectric Generator, a small radioactive energy source that for decades powered thousands of Soviet lighthouses and other navigational beacons along Russia’s Baltic, Arctic and Pacific coasts.

After the fall of the Soviet Union and the crash of the Russian economy, officials lost track of many of the RTGs as bureaucracies collapsed and records went missing. Thieves pillaged them for their valuable metal, exposing their strontium innards. Hikers and shepherds, drawn to their atomic heat, would stagger out of the woods sick with radiation poisoning.

Around Murmansk and on the Pacific coast, frightful reports about strontium elements turning up on beaches proliferated in local media. Some newly independent Soviet republics telegraphed anxieties about their inherited RTGs back to Moscow – along with requests to come take them away.

And then there was the biggest fear of all: What if strontium 90 from these virtually unguarded, remotely radiological sources ended up in the hands of terrorists who wanted to make a dirty bomb?

So far, that hasn’t happened – anybody trying to make off with a strontium battery would likely end up very ill or dead. But when three woodsmen in the former Soviet Republic of Georgia turned up in a hospital with radiation burns and caught the attention of the International Atomic Energy Agency, the dangers of orphaned Soviet RTGs were finally on everyone’s mind.

A colossal effort spearheaded by the Norwegian government entirely rid the coasts of the Barents, Kara and White Seas of more than 180 RTGs. By infusing €20 million into the push, Norway helped Russia replace the strontium 90 batteries on these lighthouses and beacons with solar power over a six year period ending in 2015.

In all, Rosatom, Russia’s state nuclear corporation, says it has decommission more than 1000 RTGs throughout the country, adding that it has mostly eliminated the hazard of these stray radioactive sources from its coastlines.

But some areas have not been so lucky, at least according to the mayor of Makarov out on Sakhalin Island, six times zones east of Moscow. Sidirov, a feisty campaigner who had been publicly heckling the capital about the nuclear trash in the seas near his town for years, says divers have located the RTG, and that he now has the coordinates of where it lies. He told Novaya Izvestiya he will pass on the RTGs location to what he calls “competent authorities” lest it end up in scheming hands.

How the RTG, which lies in 14 meters of water, came to be there is still anyone’s guess. The Russian Navy sent a statement to the newspaper insisting that all RTGs under the purview of the Pacific Fleet have been hunted down and destroyed.

But Russia’s environmental oversight agency confirmed that there were numerous radioactive foundlings in the oceans off Sakhalin Island, though they didn’t identify Sidirov’s RTG specifically.

It certainly wouldn’t be the first time someone screwed up with an RTG in the area, however. Twenty years ago, in 1997, a helicopter from Russia’s Emergency Services Ministry accidentally dropped a strontium-powered RTG into Sakhalin’s waters. It was later retrieved by the navy.

So far, Rosatom has remained mum on the veracity of Sidirov’s claim about the RTG. But since the history of the downed bomber and the other hazards in his area has been confirmed, there’s every reason to believe him about the RTG. And he wants it gone.

“The ecological authorities and the military, they’re being very stubborn about coming to collect it,” Sidorov told Novaya Izvestiya. “It’s there job to collect it – if they’re ever interested, I’ll be here to show them exactly where it is.”

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.