Climate change will turn coastal Antarctica green, say scientists

University of Cambridge

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IMAGE: Dr. Matt Davey sampling snow algae at Lagoon Island, Antarctica. view more  Credit: Sarah Vincent

Scientists have created the first ever large-scale map of microscopic algae as they bloomed across the surface of snow along the Antarctic Peninsula coast. Results indicate that this ‘green snow’ is likely to spread as global temperatures increase.

The team, involving researchers from the University of Cambridge and the British Antarctic Survey, combined satellite data with on-the-ground observations over two summers in Antarctica to detect and measure the green snow algae. Although each individual alga is microscopic in size, when they grow en masse they turn the snow bright green and can be seen from space. The study is published today in the journal Nature Communications.

“This is a significant advance in our understanding of land-based life on Antarctica, and how it might change in the coming years as the climate warms,” said Dr Matt Davey in the University of Cambridge’s Department of Plant Sciences, who led the study. “Snow algae are a key component of the continent’s ability to capture carbon dioxide from the atmosphere through photosynthesis.”

Blooms of green snow algae are found around the Antarctic coastline, particularly on islands along the west coast of the Antarctic Peninsula. They grow in ‘warmer’ areas, where average temperatures are just above zero degrees Celsius during the austral summer – the Southern Hemisphere’s summer months of November to February. The Peninsula is the part of Antarctica that experienced the most rapid warming in the latter part of the last century.

The team found that the distribution of green snow algae is also strongly influenced by marine birds and mammals, whose excrement acts as a highly nutritious natural fertiliser to accelerate algal growth. Over 60% of blooms were found within five kilometres of a penguin colony. Algae were also observed growing near the nesting sites of other birds, including skuas, and areas where seals come ashore.

The team used images from the European Space Agency’s Sentinel 2 satellite taken between 2017 and 2019, and combined these with measurements they made on the ground in Antarctica at Ryder Bay, Adelaide Island, and the Fildes Peninsula, King George Island.

“We identified 1679 separate blooms of green algae on the snow surface, which together covered an area of 1.9 km2, equating to a carbon sink of around 479 tonnes per year” said Davey. Put into context this is the same amount of carbon emitted by about 875,000 average petrol car journeys in the UK.

Almost two thirds of the green algal blooms were on small, low-lying islands with no high ground. As the Antarctic Peninsula warms due to rising global temperatures, these islands may lose their summer snow cover and with it their snow algae. However, in terms of mass, the majority of snow algae is found in a small number of larger blooms in the north of the Peninsula and the South Shetland Islands, in areas where they can spread to higher ground as low-lying snow melts.

“As Antarctica warms, we predict the overall mass of snow algae will increase, as the spread to higher ground will significantly outweigh the loss of small island patches of algae,” said Dr Andrew Gray, lead author of the paper, and a researcher at the University of Cambridge and NERC Field Spectroscopy Facility, Edinburgh.

Photosynthesis is the process in which plants and algae generate their own energy, using sunlight to capture carbon dioxide from the atmosphere and release oxygen. There are many different types of algae, from the tiny, single-celled species measured in this study, to large leafy species like giant kelp. The majority of algae live in watery environments, and when excess nitrogen and phosphorous are available they can multiply rapidly to create visible algal blooms.

The researchers say that the total amount of carbon held in Antarctic snow algae is likely to be much larger because carbon dioxide is also taken up by other red and orange algae, which could not be measured in this study. They plan further work to measure these other algal blooms, and also to measure the blooms across the whole of Antarctica using a mixture of field work and satellite images.

Antarctica is the world’s southernmost continent, typically known as a frozen land of snow and ice. But terrestrial life can be abundant, particularly along its coastline, and is responding rapidly to climate changes in the region. Mosses and lichens form the two biggest visible groups of photosynthesising organisms, and have been the most studied to date. This new study has found that microscopic algae also play an important role in Antarctica’s ecosystem and its carbon cycling.

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From EurekAlert!

61 thoughts on “Climate change will turn coastal Antarctica green, say scientists

  1. OK, so I expect the University of Cambridge to colonize Antarctica, especially along the western side of the Peninsula. Here’s the name for their colony: Vikings II. What a hoot. Stay sane and safe (dogs wondering why no walk today…looks like they can’t count any better than U. Cambridge).

  2. Eureka! Chaos (“evolution”), with, hopefully, an anthropogenic fitness function..

    So, they believe it is climate change (i.e. uniform warming over a 30 year period), not anthropogenic, and not catastrophic, with a green, perhaps Green, future.

  3. If, as the article asserts, this is “the first ever large-scale map of microscopic algae as they bloomed across the surface of snow along the Antarctic Peninsula coast” then how can any conclusions be drawn as to what behavior the algae “bloom” has had, or will have in the future?

    How is it possible to state “Results indicate that this ‘green snow’ is likely to spread as global temperatures increase”? Isn’t it possible that, as temperatures increase, there will be organisms that also “bloom” to consume this algae as a food source . . . this happens regularly in the world’s oceans . . . thereby limiting the algae’s geographic growth extent, or perhaps even reversing it?

    And what might happen if increasing global temperatures force the nearby bird populations to go elsewhere, thereby depriving the snow algae of their needed “fertilizer source”?

    • Indeed, how is it possible?
      Did they forget this?

      “Observing something for the first time, doesn’t mean it has never happened before.”

      • Indeed, on returning to Amsterdam in 1698 Willem de Vlamingh reported to the good burghers that in the Antipodes climate change was turning swans black.

    • They also state that the total size of the blooms is only 1.9 sq kilometers.
      How “large” scale can those maps be?

    • “Over 60% of blooms were found within five kilometres of a penguin colony.”

      Errr … how did it get there? Pooping into an Antarctic gale? Was there any growing around and within the penguin colony? Why not? Real scientists don’t toss off thoughts as they pop into their heads.

      Has anyone ever seen a climate science report that says, gee I guess this isn’t related to climate change after all as we thought it was. What are the odds that what one goes out to find is always found and that it is related to climate change and that the change is bad?

      Remember the Ship of Fools study from The Centre for Excellence in Climate Science Research in Australia that got stuck in pack ice in mid summer searching for CAGW affects on Antarctica. They found it and the Project Leader got a big award for it?

      No wonder 97% Cook was able to find 12,000 climate science papers published in peer reviewed journals over a decade! That’s the only startling thing about his study to my mind, thats 3 papers a day, every day! With 4 months ‘holidays and and weekends off work months, thats a 180 work days a year, so the pile of papers works out to 6 scientific papers a day published! S’Truth!

  4. this is where your grant money goes…

    Results indicate that this ‘green snow’ is likely to spread as global temperatures increase.

    • The WX there was never tropical in the past 100 million years. Its forests were boreal. Hard to be tropical in the land of the midnight sun. Got pretty warm under 24 daylight in summer, but tropical, no.

      • I have a lot of respect for you, John, always love your comments. But, can’t we type the word “weather”? WX just sounds pretentious.

  5. “The team found that the distribution of green snow algae is also strongly influenced by marine birds and mammals, whose excrement acts as a highly nutritious natural fertiliser to accelerate algal growth.” duh? Anybody remember guano? And El Niño? Nice to know about photosynthesis. Where are the ice worms, wrong hemisphere?

    I saw this in 1973, shrimp were so thick that numerous rostrums stuck you when you waded and Powell, G. V, et al. 2010. Effects of seabird nesting colonies on algae and aquatic invertebrates in coastal waters. Marine Ecology Progress Series. 417:287-300. DOI: https://doi.org/10.3354/meps08791. They might cite this since it is in their millennium. There are earlier papers in the last one. Sorry kids, it’s getting harder to say that there is no such thing as a dumb question, etc.

  6. Isn’t the antarctic peninsula surrounded (or at least home to- several active under water volcanoes..
    Nice source of heat and fertilizer..

  7. Scientists have created the first ever large-scale map of microscopic algae as they bloomed across the surface of snow along the Antarctic Peninsula coast. Results indicate that this ‘green snow’ is likely to spread as global temperatures increase.

    So if this is the first ever map, how do they know if it’s static, increasing of decreasing? Just because you’ve observed something for the first time doesn’t mean it hasn’t been there all along.

    • Well it’s like coral bleaching coming to attention with scuba diving in the 1980s on the GBR and then it’s worse than it was silly. Do keep up.

  8. They seem surprised (with the clear implication that this is the result of warming) that there is algae growing on the northern half of the Antarctic Peninsula and nearby islands. Fact – much of this area is north of the Antarctic Circle . If you look north to the Arctic Circle in Alaska and Canada and Russia, you find taiga and tundra, even fuller forests in places. So, what’s the big deal re plant life?
    This follows a lot of rubbish talked about temperatures in the Peninsula in recent years with hysteria when (Fohn wind-induced) temperatures exceed 15C. Yet this is totally unsurprising given just how far north the northern half of the Peninsula is. It may be in “Antarctica” but the climate cannot be expected to be continuously “Antarctic” in the full frigid sense.

  9. Antarctica: 13,209,000 km2
    Blooms of green algae: 1.9 km2

    It must have been like looking for a needle in a haystack to find the green algae. When there is grant money, there is a way.

  10. “Over 60% of blooms were found within five kilometres of a penguin colony. Algae were also observed growing near the nesting sites of other birds, including skuas, and areas where seals come ashore.”

    Or it could be that birds and such choose to nest where temperatures are less-cold, just as the algae does. Which comes first?

  11. These will make great military bases for Russia and China……while the real targets of the climate crusades pay up with or without this outcome.

  12. They haven’t actually measured this snow algae increasing in area, they just assume that it must be.

    The algae currently covers less than 2 sq kilometers. If it doubles in size, it will cover another 2 sq kilometers.
    That works out to what percentage of the size of Antarctica?

    They note that the algae is only found near areas where birds nest.
    This would mean that the only way for the size of the algae blooms to increase would be for the size of the bird colonies to also increase. Isn’t more life a good thing?
    Beyond that, they claim that if Antarctica warms (another thing they assume, rather than measure) that the algae blooms will increase in size. However their own data shows that the algae blooms are only found near bird colonies. So aren’t they contradicting themselves?

  13. I know I will not live long enough to see it but I sure would like to see 60 degree weather in Feb here in Ontario.

  14. “Scientists have created the first ever large-scale map of microscopic algae as they bloomed across the surface of snow along the Antarctic Peninsula coast. Results indicate that this ‘green snow’ is likely to spread as global temperatures increase.”

    The peninsula is the zone where increased advections of warm air converge while higher pressure catabatic winds descend from the continent.
    https://climatereanalyzer.org/wx_frames/gfs/ds/gfs_nh-sat6_t2anom_1-day.png
    https://climatereanalyzer.org/wx_frames/gfs/ds/gfs_nh-sat6_prcp-tcld-topo_1-day.png

    To claim this has to do with global temperatures is dishonest and false.

  15. Like a lot of articles on biological processes that are supposed to be a marker of climate change they completely ignore the direct role of CO2 as a fertilizer for plant growth. I bet that a lab experiment would show that increased CO2 in the air allows this algae to grow better at current temperatures.

  16. About 40% of Antarctica is Australian territory*, so if it warms up enough to be farm land, we’ll be OK.

    (That’s what we say, anyway. And four countries agree.)

  17. Here is a web article that describes the time period inferred for the first appearance of algae (like green algae on Earth), https://ucmp.berkeley.edu/precambrian/proterozoic.php
    The time era in question was the Mesoproterozoic (1.6 to 1 billion years ago) era, part of the Proterozoic eon of time. It was during this time that we had “(an) explosion of eukaryotic forms. These included multicellular algae..”

    So, one billion years ago or more for the emergence of green algae.

    Face it, the stuff has been around *forever*. Just because someone decides to study something that doesn’t make it new!

    By the way, is ‘green’ somehow universally a bad thing now, or what?

  18. Well, how about the climate starting to change there in the first place? So far Antarctica has been totally reluctant to warm up at all. And I am afraid, as long as we do not start to put a lot of contrails over Antarctica it is not going to change.

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