Arctic Glaciers Face 'Terminal' Decline As Microbes Accelerate Ice Melt 35
Scientists in Svalbard warn Arctic glaciers are in "terminal" decline, with microbe-driven biological darkening accelerating ice melt and potentially triggering major climate feedback loops. The Guardian reports: Recent research implicates snow and ice-dwelling microbes in positive feedback loops that can accelerate melting. With more than 70% of the planet's freshwater stored in ice and snow -- and billions of lives sustained by glacier-fed rivers -- this has profound implications everywhere. Yet not all polar microbes amplify global heating. Emerging evidence suggests that certain populations are -- for now -- applying a brake to methane emissions. [...] Microbes that live in surface ice and snow produce dark-colored pigments to harness sunlight and shield themselves from damaging UV light. They also trap dark-colored dust and debris. Together, these factors darken snow and ice, causing it to absorb more heat and melt faster -- a process known as "biological darkening."
Microbes also respond to global changes, such as increased nutrients from air pollution, wildfire smoke or wind-blown dust from receding glaciers and expanding drylands. "The snowpack chemistry is now different to preindustrial era snow," Edwards says. Rising temperatures and longer melt seasons caused by global heating further accelerate the growth of ice-darkening microbes. Together, these factors have the potential to trigger an amplifying positive feedback loop: ice-darkening microbes nudge up temperatures and accelerate melt, exposing more nutrient-rich debris that encourage the growth of yet more microbes, which darken the surface further still.
Each summer, a biologically darkened zone, visible from space, covering at least 100,000 sq km, appears on the south-western part of the Greenland ice sheet. According to a 2020 study, microbes there are responsible for 4.4 to 6.0-gigatons of runoff, representing up to 13% of total melt, from an ice mass that holds enough water to raise global sea levels by more than 7 meters. These effects are acknowledged in IPCC reports but not yet incorporated into climate projection models. Across the European Alps, Himalayas, central Asia and beyond, at least 2 billion people depend on glacial meltwater for drinking water, agriculture and hydropower. Yet even if the world meets Paris targets, half these glaciers will not survive this century.
Microbes also respond to global changes, such as increased nutrients from air pollution, wildfire smoke or wind-blown dust from receding glaciers and expanding drylands. "The snowpack chemistry is now different to preindustrial era snow," Edwards says. Rising temperatures and longer melt seasons caused by global heating further accelerate the growth of ice-darkening microbes. Together, these factors have the potential to trigger an amplifying positive feedback loop: ice-darkening microbes nudge up temperatures and accelerate melt, exposing more nutrient-rich debris that encourage the growth of yet more microbes, which darken the surface further still.
Each summer, a biologically darkened zone, visible from space, covering at least 100,000 sq km, appears on the south-western part of the Greenland ice sheet. According to a 2020 study, microbes there are responsible for 4.4 to 6.0-gigatons of runoff, representing up to 13% of total melt, from an ice mass that holds enough water to raise global sea levels by more than 7 meters. These effects are acknowledged in IPCC reports but not yet incorporated into climate projection models. Across the European Alps, Himalayas, central Asia and beyond, at least 2 billion people depend on glacial meltwater for drinking water, agriculture and hydropower. Yet even if the world meets Paris targets, half these glaciers will not survive this century.
So, Earth is dying? (Score:4, Informative)
Re: So, Earth is dying? (Score:3)
Not dying but some parts of New York will probably but under water.
Re: So, Earth is dying? (Score:1)
Al gore told us it would be underwater.
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Earth will be fine. Life on it, on the other hand, not so much.
It will get especially bad for the most destructive species.
But don't you worry, you're safe, ignoring the problems will make them go away.
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But don't you worry, you're safe, ignoring the problems will make them go away.
Yep. It is a real eye-opener how many people actually believe that works.
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Earth will be fine. Life on Earth will be fine. Humanity and modern society? That's a more complicated question.
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Life on Earth will be fine
Yeah, really fine. [nature.com]
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Earth is fine. This isn't the first mass extinction event and it won't be the last. Of course some species will die out, but more broadly, life is remarkably resiliant.
We're not destroying the Earth, we're destroying OUR habitat and the things WE depend on. It's our water supply that we're endangering; algae doesn't care what we do.
Poor glaciers (Score:4, Interesting)
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I'm guilty. I do a lot of things right. But last week I rode my motorcycle on a 650 km round trip to get a brisket sandwich.
Now, to be fair, the sandwich was an excuse for the thing I really wanted, which was the ride. But it turned out to be an amazing sandwich.
My motorcycle use is frivolous and unnecessary. It makes trips ten times longer than necessary, and convinces me to go out for single tasks. I'll even leave on a Sunday without checking if the target business is open.
So I'm part of the problem. In f
So, we'll go nuclear then? (Score:1, Troll)
What's that, no? Just more kvetching and politics? Because that's been working so well?
Well, okay then ... carry on.
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I guess a society like the US can access economies of scale but the renewables lobby have consistently stated that regardless of 'politics', fission is too expensive and construction should have started 25 years ago.
Don't ask me, I'm just a consumer buying electricity from a multinational.
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Oh lot's of countries are, just not the US. We voted against nuclear and for gas and coal in 2024.
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I mean thanks to conservatives deciding "the market" can do nuclear and have spent the last 6 decades destroying any strong institutions and thus we have so few reactors since the government. The track record speaks for itself.
Almost every reactor being built today across the globe is from a State Owned Enterprise. When will Republicans support one of those?
SIGH (Score:3, Funny)
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I have been reading /. for quite a long time, and I can't remember when the anti-science wackadoos weren't everywhere. Climate change denialism is at least as old as the PC vs Mac wars, from my (admittedly failing) memory.
I'm not sceptical about climate change, just a denialist about the potential of the human population to make hard choices to repair the damage caused so far by the Anthropocene. The ten hottest years on record, globally, have all been since 2015, and in response the US elected someone wh
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Agree with all of what you say.
Trump's election is a symptom of the bigger problem, was my point. Whether his administration takes our collective velocity towards the cliff edge from 75 mph to 77 mph doesn't matter a whole lot in the long term. Kamala Harris might have enacted policies to take the velocity from 75 mph to 72 mph. So what? Same issue.
The electric car outside my house and the 10kW/h solar system on my roof both help reduce emissions in the absolute sense, but not in a meaningful sense. I u