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Pergélisol / permafrost et méthane / CO2 gelés

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The chilling science on Alaska’s melting permafrost. Up to a quarter of the permafrost that lies just under the ground surface in Alaska could thaw by the end of the century, releasing long-trapped carbon that could make its way into the atmosphere and exacerbate global warming, a new study finds.

The chilling science on Alaska’s melting permafrost

The study, detailed in the journal Remote Sensing of Environment, maps where that near-surface permafrost lies across Alaska in more detail than previous efforts. Permafrost may not be the ticking “carbon bomb” scientists once thought. This story was originally published by the Guardian and is reproduced here as part of the Climate Desk collaboration.

Permafrost may not be the ticking “carbon bomb” scientists once thought

The ‘carbon bomb’ stored in the thawing Arctic permafrost may be released in a slow leak as global warming takes hold, rather than an eruption, according to new research. Scientists at the U.S. Thawing permafrost could be the worst climate threat you haven’t heard of. Some things get better when you take them out of the freezer.

Thawing permafrost could be the worst climate threat you haven’t heard of

Ice cream, for example, is unarguably more delicious when it gets a little melt-y. (Unarguably, I say! Come at me, trolls.) But other things get remarkably worse. D'incroyables bulles apparaissent sous la surface d'un lac gelé au Canada. A BP spill’s worth of methane is leaking from the ocean off of Washington every year. You know how ocean temperatures have been on the rise lately?

A BP spill’s worth of methane is leaking from the ocean off of Washington every year

Well, it might mean a more comfortable day at the beach, but if you’re in the Pacific Northwest, I have some bad news for you: According to a new study, because of the temperature rise, we could see a huge release of deep-sea methane off the coast of Washington state. One of the researchers compared the amount of methane currently being released to the amount of oil that gushed from the BP oil spill.

“We calculate that methane equivalent in volume to the Deepwater Horizon oil spill is released every year off the Washington coast,” said Evan Solomon, a coauthor of the study, which was published in Geophysical Research Letters. And if the water in the region warms by 2.4 degrees C by 2100, the size of that annual methane release could quadruple. Melting Permafrost Endangers Greenland and Releases Harmful, Disease-Causing Bacteria 

People love stories.

Melting Permafrost Endangers Greenland and Releases Harmful, Disease-Causing Bacteria 

Sometimes they make them dream, sometimes they frighten them, but stories always make people think. The story I want to tell is the story of a small village in Greenland, Uummannaq. Antarctica’s permafrost is melting. Things are getting ugly on Earth’s underside.

Antarctica’s permafrost is melting

Antarctic permafrost, which had been weathering global warming far better than areas around the North Pole, is starting to give way. Scientists have recorded some of it melting at rates that are nearly comparable to those in the Arctic. Permafrost thaw exacerbates climate change. The climate is warming in the arctic at twice the rate of the rest of the globe creating a longer growing season and increased plant growth, which captures atmospheric carbon, and thawing permafrost, which releases carbon into the atmosphere.

Permafrost thaw exacerbates climate change

Arctic Methane Emissions 'Certain to Trigger Warming' As climate change melts Arctic permafrost and releases large amounts of methane into the atmosphere, it is creating a feedback loop that is "certain to trigger additional warming," according to the lead scientist of a new study investigating Arctic methane emissions.

Arctic Methane Emissions 'Certain to Trigger Warming'

Les cratères géants de Sibérie sont-ils dus au réchauffement climatique. La vidéo d'un cratère géant de 30 mètres de diamètre, apparu dans la péninsule de Yamal, en Sibérie, avait passionné les internautes à la mi-juillet et donné lieu à toutes sortes d'élucubrations pour l'expliquer : impact d'une météorite, invasion extra-terrestre ou même missile intergalactique.

Les cratères géants de Sibérie sont-ils dus au réchauffement climatique

Sunlight stimulates release of carbon dioxide in melting permafrost. Regions of melted permafrost in the Arctic.

Sunlight stimulates release of carbon dioxide in melting permafrost

(Rose Cory / PNAS ) Ancient plant and animal matter trapped within Arctic permafrost can be converted rapidly into climate-warming carbon dioxide when melted and exposed to sunlight, according to a new study. In a report published Monday in the Proceedings of the National Academy of Sciences, a team of environmental and biological scientists examined 27 melting permafrost sites in Alaska and found that bacteria converted dissolved organic carbon materials into the greenhouse gas CO2 40% faster when exposed to ultraviolet light.

Another reason to worry about methane: It’s leaking out of the Arctic Ocean hella fast. We learned last week that Al Gore has become a vegan, and speculated that it might be because methane emissions from livestock are a surprisingly large driver of climate change. Meanwhile, a recent report from the National Academy of Sciences argues that the U.S. EPA has vastly underestimated methane emissions because it calculates them from the bottom-up — how much methane does a cow release times how many cows there are, for example — rather than actually measuring the methane released into the atmosphere. We often talk about greenhouse gases and carbon dioxide as if they are one and the same. CO2 is by far the most prevalent greenhouse gas, but while much less methane is released into the atmosphere, methane is about 21 times more potent over a 100-year period.

15/12/2011...Arctique, la découverte inquiétante de véritables fontaines de méthane d'1 km de diamètre. Le réchauffement global est peut-être en train de s'emballer. Une expédition scientifique russe a observé plus de 100 fontaines de méthane d'une ampleur jamais vue émergeant de l'océan Arctique, au nord de la Russie, rapporte le journal britannique The Dailymail. Il faut rappeler que le méthane est un gaz à effet de serre 20 fois plus puissant que le gaz carbonique. Dans le passé, nous avions déjà observé des structures comme celles-ci, mais elles ne faisaient que quelques dizaines de mètres de diamètre, a affirmé le chef de l'expédition, Igor Semiletov.

Cette fois, nous en avons trouvé des beaucoup plus impressionnantes, elles font plus de 1000 mètres de diamètre. Melting Sea Ice Causes Spike In Arctic Air Pollution. As our use of fossil fuels continues to exacerbate global climate change, we’re starting to see the quantifiable effects of our rapidly warming planet. One of the most obvious effects is the rapid decline in arctic sea ice, one of the earth’s largest carbon sinks and a catalyst of life for beings all over the planet.

This melting ice spells disaster for polar bears and other animals that depend on it for food and shelter. But as a NASA-led study recently discovered, homeless polar bears and invasive crabs aren’t the only horrifying consequences of the sea ice decline. Immense Algae Bloom Signals Major Change in Arctic. NOTE: This is a guest post from Sarah Bedolfe, Coordinator of Marine Research for One World One Ocean.

Last July, scientists happened upon a massive phytoplankton bloom in the Arctic, like none seen before. It covered 100 km (62 miles) and was dense enough to make the water green and murky — it contained four times as much phytoplankton as neighboring areas. One scientist said it was like “finding the Amazon rainforest in the middle of the Mojave Desert,” according to CNN. “Suddenly, the fluorometer went nuts. Arctic melt releasing ancient methane. 20 May 2012Last updated at 12:54 ET By Richard Black Environment correspondent, BBC News.

Réchauffement climatique - Quand le pergélisol… - Gaz de schiste :… - Copenhague :… - Charles… - Dérèglement… Depuis quelques semaines, on a vu apparaître ce nom dans les médias et pour cause : c’est une véritable bombe écologique et économique qui affectera potentiellement nos sociétés et notre avenir ! Tout d’abord, quelques explications sur le gaz de schiste. Il s'agit d'un gaz qui est réparti de manière diffuse dans les couches géologiques très profondes, en l'occurence, le schiste. Pour l'extraire, il faut creuser des puits horizontaux, fracturer ensuite la roche par injection d'eau sous forte pression, ajouter un cocktail de produits chimiques très dangereux et récupérer ensuite le gaz présent. Il ne s'agit pas d'une découverte récente mais la hausse du prix du gaz depuis 2000 a rendu son coût d'extraction plus compétitif. Alors que les réserves seraient 4 fois plus importantes que celles du gaz "conventionel", on pourrait crier victoire face à ces nouvelles ressources potentielles....mais hélàs, c'est bien le contraire qui se présage !

Une bombe écologique Une bombe géopolitique. Twice as Much Methane Escaping Arctic Seafloor. The Arctic methane time bomb is bigger than scientists once thought and primed to blow, according to a study published today (Nov. 24) in the journal Nature Geoscience. About 17 teragrams of methane, a potent greenhouse gas, escapes each year from a broad, shallow underwater platform called the East Siberian Arctic Shelf, said Natalia Shakova, lead study author and a biogeochemist at the University of Alaska, Fairbanks. A teragram is equal to about 1.1 million tons; the world emits about 500 million tons of methane every year from manmade and natural sources.