Surprise! Greenland ice sheet melting being driven by ice-loving algae

From the American Geophysical Union and the “but we’ll still find a way to blame CO2, just you wait” department. It seems this is a frustrating day for climate-ice researchers, earlier, it was found that ice cores used to determine ancient CO2 levels are likely contaminated by microbes, and they altered the gas mixture balance.

Algae growth reduces reflectivity, enhances Greenland ice sheet melting

WASHINGTON D.C. — New research shows algae growing on the Greenland ice sheet, the Earth’s second-largest ice sheet, significantly reduce the surface reflectivity of the ice sheet’s bare ice area and contribute more to its melting than dust or black carbon. The new findings could influence scientists’ understanding of ice sheet melting and projections of future sea level rise, according to the study’s authors.

Glaciologists have long known materials such as mineral dust and black carbon can darken the surface of large ice sheets. Scientists study these impurities because they reduce the sheet’s albedo, or the extent to which it reflects light, which increases melting of the ice and affects projections of sea level rise. But few studies had examined the darkening effect of algal cells, which naturally grow on the ice sheet.

Microphotographs of ice algae (mostly the species Ancylonema nordenskioldii). CREDIT
Marian Yallop

The new study quantitatively assessed how surface ice algae contribute to darkening of the ice sheet, and found the algae reduce the ice sheet’s albedo significantly more than non-algal materials, like mineral particles and black carbon. Algal darkening is responsible for 5 percent to 10 percent of the total ice sheet melt each summer, according to the new research published in Geophysical Research Letters, a journal of the American Geophysical Union.

The findings sharpen the way glaciologists think about melting of ice sheets and how ice reflects light, according to Marek Stibal, a cryosphere ecologist at Charles University in Prague, Czech Republic and one of the lead authors of the new study. A warming climate could also increase algal growth in the future, potentially boosting algae’s influence on ice sheet melting, he said.

“The novel aspect of our study is that we discover biological processes play an important role in ice sheet behavior,” Stibal said. “Glaciologists usually only look at inorganic materials when studying light reflectance and ice melt because biological processes are often too complicated to capture. But we find organisms can have a large-scale effect on a system that was previously studied in an abiotic context.”

Studying algae in the field

Previous studies suggested impurities such as black carbon and dust drive melting of bare ice on the lower part of the ice sheet. Impurities darken the surface of the sheet, reducing its albedo and allow it to absorb more light. The increased absorption of solar radiation raises the temperature of the ice sheet and accelerates the melting process.

Absorption of sunlight is responsible for most of the ice melt in Greenland, according to Jason Box, a climatologist at The Geological Survey of Denmark and Greenland and the other lead author of the new study.

Microbes such as algal cells colonize the ice and can accumulate over time given enough sunlight, water and nutrients. Surface ice algae produce dark pigments to protect themselves from high intensity radiation, further darkening the sheet surface, Stibal said.

The authors of the new study headed into the Greenland ice sheet in the summer of 2014 to quantify the contribution of algae to the darkening effect. Several members of their team camped at a study site in the southwestern region of the ice sheet for 56 days while gathering data on the sheet’s reflectivity and algal population.

An aerial view of the study area on the Greenland ice sheet. CREDIT Jason Box/Jonathan Ryan

Stibal and his colleagues used portable spectrometers and albedometers to measure the reflectivity spectrum of the bare ice surface each day. They also collected samples of surface ice and used a field microscope to characterize the algae and count the number of algal cells in each sample. They analyzed the relationship between the growth of the algae and the amount of light being reflected by the ice sheet surface.

The authors found the ice sheet reflected significantly less light as the algal population grew. They calculated algal growth accounted for approximately 70 percent of the variation in the light reflectance data, making it the dominant contributor to the phenomenon. The rest of the variation was due to rain and how much time had passed, and non-algal impurities weren’t significant in their analysis.

Study co-author Nathan Chrismas collecting surface ice for analysis.
CREDIT Karen Cameron/Sara Penrhyn Jones

The new study didn’t estimate how much more ice could melt in the future due to algal darkening. But the results can lay the groundwork to devise more accurate projections of sea level rise scenarios due to melting ice from Greenland and other ice sheets, Stibal said. Algae grow on other ice surfaces in areas such as the Himalayas, where they reside on water-producing glaciers.

He also believes a warming climate could be a boon to algal populations, potentially increasing their darkening influence.

“As the climate warms, the area that the algae can grow in will expand, so they’ll colonize more of the ice sheet,” he said. “Additionally, the growing season will lengthen, so the contribution of algae to melting of the ice will probably increase over time.”

Nozomu Takeuchi, professor of earth sciences at Chiba University in Japan, said the new research highlights the importance of accounting for biological processes in the cryosphere, and believes the study will have an impact on glaciological research of the Greenland ice sheet.

“The major implication of their findings is that the ice sheet is not a simple abiotic system of snow and ice, but rather an ecosystem,” he said. “Understanding this biological process more quantitatively could induce a new perspective on other climate cycles of the Earth, such as glacial-interglacial cycles.”



60 thoughts on “Surprise! Greenland ice sheet melting being driven by ice-loving algae

  1. Okay let’s have some honesty here and get a show of hands about how many researchers fertilized the ice microbes while doing field work.

    • I am a bit concerned as well that camping next to a microbial collection spot probably wasn’t the best scenario for collecting pristine samples. It’s rather quaint that image of the researcher standing in the collection spot at least had surgical gloves on. No telling where he was walking through prior to stepping into the collection zone. Seem like a lot of footprints around that spot.

  2. As presumably the ice-dwelling bacteria and algae are nothing new, except for not being properly noted, how does that change anything?

    • Well of course global warming will increase the number and activity of the algae, meaning like everything else lefties are concerned about – WE”RE ALL GOING TO DIE. With the repeal of net neutrality, tax reform, and global warming, all of which cause instant sudden death, there is at least no longer any need to worry about trivialities like cancer anymore. In fact we should probably stop funding cancer research and all other forms of medical research, BECAUSE WE”RE ALL GOING TO DIE NOW.

    • It shows that even though they didn’t account for this at all, it means they were even more right than they claimed all along. /s

    • its a new positive feedback to stick into the equation (to mitigate the previously ignored overwhelming negatives that can no longer be ignored).

    • Why does it matter? The underlying assumption used to estimate temperature and gas levels from ice cores are based on an assumption that the samples are pristine. Now, each layer of ice may or may not have been contaminated in the past. The problem is that to push an agenda, sloppy science has become the norm. Computers models all suffer from the same limitation, garbage in, garbage out. If the validity of the proxy data is questionable, the conclusions concerning gas levels and temperatures come into question.

    • CO2 fertilisation is likely to have a much larger effect on algal growth than a minuscule change in temperature I would think. Also when looking at algae I don’t think you can impute the warming effect from colour alone. The colour of algae is due to chlorophyll and consequently much of the light absorbed is fuelling photosynthesis and not heating the ice.

  3. We must save the planet, nuke that algae, kill it, kill it, or we are all going to Die. (Oops–I think we are going to die anyway. So, never mind.)

  4. “Study co-author Nathan Chrismas collecting surface ice for analysis … ” appears to be scraping away all the nice white snow to get to the surface ice for the proper analysis.

  5. Hmm, so an increase in atmospheric CO2 fertilizes the photosynthetic bacteria causing it to grow faster, causing a darker ice surface, leading to faster melting ice? (that would assume there is no other nutrient bottleneck that prevents the bacteria from growing faster or becoming more abundant)

    It still seems this could only occur where there is a high enough temperature and sunlight to get ice to its melting point, so it wouldn’t affect most of the world’s ice and even then just except seasonally. I wonder what happens to the bacteria as it becomes buried in a growing ice field? Where is all that extra carbon going within the ice?

    • The UN must immediately organize an areal algaecide spraying program in Greenland. Otherwise the entire thing will actually turn green, all the ice will melt and sea levels will rise by 100 meters. Or maybe not.

      • our actual civilization started after the last two glaciations , after the billions more ice mass than today that could smelt , has smelted .
        Everything is Nature and natural, but today’s so called scientist see everything what is natural as absolutely bad and worst against the virtual reality they schizophrenic imagine . In their insanity minds the Nature is always wrong ! This is the new “scientific exceptionalism” as it is the Obama-Trump USA “exceptionalism”
        This is the new “scientific Talibanism” !

  6. Their quest for the “Arctic Death Spiral” is never-ending. If only the Arctic would cooperate! Because once the Arctic goes, then climate goes to Hell in a handbasket. Hope springs eternal for these Alarmists.

  7. Its almost as if this stuff is, I dunno, complicated or something.

    Quick! Get another picture of a polar bear with a broken foot on the news, its the only way we can keep the narrative going…

  8. If these algae can carry out photosynthesis, wouldn’t they be removing CO2 from the atmosphere at the same time they absorb sunlight and melt the ice?

    What happens to these algae in the autumn and winter when there’s no sunlight in Greenland? Do they die or just go dormant like deciduous trees do? Wouldn’t any meltwater re-freeze in the winter?

  9. Every mountain climber knows this. Climate scientists don’t get out much. Summer snowfields all over the world are pink from algae, and are concentrated in the neve penitentes (suncups), where they dine on all the chemicals in the snow. And the suncups act as traps for all the wind-borne nutrients, and concentrate solar radiation. The algae modify their environment to better suit themselves. As a result, the snowfields melt faster than they would have otherwise (more water and energy for the algae).

    When the annual snows melt/sublimes, the algae live on the outer skin of the permanent underlying icefield. We have seen pink snows, and pink ice.

    The algae are everywhere, and come with the dust that blows onto the snows, as well as they are probably airborne and live in clouds. Since snowfields that disappear each summer, have pink snow every year.

    And I do believe the included picture shows the subtle shade of pink snow in the middle right.

    Sometimes science by reductionism seems to miss the obvious – that it’s an integrated ecosystem.

    • Easy to believe in the continental mountains. But the middle of the Greenland ice sheet should be quite different, surrounded mostly by ocean expanses and tundra, so nutrient poor.

  10. These are going to be very slow growing independent of CO2 concentration because nutrient limited. Possibly some nitrate from polluted atmosphere washout. But were are these ice cap algae going to find sufficient phosphate and potassium, plus the trace iron for photosynthesis in order to grow to become an AGW problem? Cryosphere 11 (2017) has a recent article bynother authors on Greenland ice sheet darkening that has a separate section in ice algae, which indeed highlights the nutrient limitation.

    • The algae are dependent on dust deposition for nutrients. Conditions were quite possibly better a hundred years ago, when there were both more forest fires and much more coal burning in North America.

    • Many algae are fixers of atmospheric nitrogen. Climate science should include more Biology.
      From 1941:
      G. E. FOGG
      Botany School, Cambridge
      (Received 30 December 1941)
      (With Two Text-figures)
      RECENT work, particularly that of De (1939), has shown that some blue-green algae
      are capable of utilizing the free nitrogen of the atmosphere in the synthesis of cell

    • Yeah the question is how slow ristvan the microbes will move thru this stuff much easier than rock. If you look at deep subsurface microbes there penetration rate is limited by their slow lifecycle it may or may not be the same for these. It’s the old case of more study needed.

  11. As usual when there is some sensational new discovery made about the Greenland ice, I go back to A E Nordenskiöld who was the first scientist ever to visit the ice-cap back in 1870. And, yes, as usual he had discovered the microorganisms, and yes, he realized that they were climatically important because they darkened the ice:

    (unfortunately in Swedish)

    A swedish biologist even published a major paper (60 pages) on the “ice flora” in 1886:

    Why don’t scientist ever discover anything new nowadays? And why don’t they bother to check relevant references? It took me about five minutes.

    • Take a look at the first paragraph from the “Results and Discussion” section of this study from 2004:

      Bacterial Activity at −2 to −20°C in Arctic Wintertime Sea Ice
      Karen Junge, Hajo Eicken, and Jody W. Deming
      Appl. Environ. Microbiol. January 2004 70:1 550-557; doi:10.1128/AEM.70.1.550-557.2004


      For the entire range of temperatures examined, including the coldest (−20°C), microscopic observations of intact ice sections revealed numerous liquid brine inclusions that were inhabited by bacteria (Fig. 1 and 2). On the scale of a bacterium, a substantial volume of habitable brine-filled pore space has been shown to exist within the ice matrix even at −20°C, with both isolated and fully connected brine tubes, veins, and junctures occurring at densities exceeding 150 mm−3 (17); these densities are almost 2 orders of magnitude higher than those reported in previous studies at lower magnifications. This reservoir of unfrozen water, a prerequisite for microbial activity, allows for fluid flow induced by local thermomolecular pressure gradients or larger-scale temperature gradients (10, 52) as well as for possible movement of bacteria within the ice (22, 37).

      And this has been going on for how long? And for how long has ice transformed over geological time scales, … under the same laws of physics? And is it possible that this combined consistent transformation of ice, with associated consistent microscopic habitation, could produce consistent patterns IN THE ICE that have been interpreted as a proxy for consistent patterns OUTSIDE THE ICE (in the atmosphere)?

      … back to the same questions that I had in 2010.

    • They don’t have to – they just regurgitate and add something about CAGW and ‘it’s worse than we thought’ and asks for more funding…..

  12. Lets see – The algae, being living critters, optimize there use of available energy. Since that energy happens to be light, specifically sunlight, — OH WAIT! – they absorb more than ordinary dirt and dust! If they absorb the light the heat energy is available at the ice surface to warm/melt some ice. Since they are more efficient than regular dust at collecting energy the ice melts quicker. Any surprises here?

    • Keep in mind that photosynthesis converts light energy into chemical bonds, extracting some of the ‘heat’ energy and fixing it as biomass.

      • new biomass add more captor, new heat, more that it distract part of the light into chemical bonds instead of heat.
        And these chemicals also act as anti-freeze, THAT, more than extra heat, is causing the melting.

  13. I’ve been cheering the mighty greening of the planet and enjoying nature’s rascally sense of humour in taunting the cheerless CO2 worriers as we march toward Garden of Eden Earth by mid century, when population has peaked (we are 80% of the way and an end to Malthus moping).

  14. Another example that global warming is not just a matter of Physics as measure in a lab or as simulated in a computer model. This was clear to any real = skeptical scientist since ages.

  15. Where’s Monsanto when you need them?
    Leave the only sensible option: to prevent critters melt ice, let us flame-throw /napalm them to death.

  16. ““Understanding this biological process more quantitatively could induce a new perspective on other climate cycles of the Earth, such as glacial-interglacial cycles.”

    Perhaps it is algae that experience rapid growth and coverage during the time in Milankovitch cycles when obliquity is increasing, precession moves NH winter solstice closer to perihelion and eccentricity is low. As Earth approaches these conditions this rapid algae growth could help with the melting of the great ice sheets of the NH. As these conditions wane and obliquity decreases, NH winter solstice moves toward aphelion and eccentricity increases algae growth could be reduced to a point where the ice sheets can grow again taking Earth back into the full glacial period.

  17. These ice algae are mostly pennate diatoms, surviving at -20C are mostly overwintering like some Arctic biota. Although these algal cells are heavily pigmented, they are not photosynthetically very active. Their pigments are dark yellow and together with the oil globules stored may cause the black hue under reflected light.

  18. Albedo is appropriately used to characterize the relative brightness of celestial objects (of which Earth is a member), particularly when they are dominated by diffuse reflectors such as regolith or clouds. Snow is approximately a diffuse reflector, so it might be reasonable to refer to the ‘albedo’ of snow. However, it does have a strong forward lobe of reflectance because of the tendency for snowflakes to lie sub-parallel to the surface. On the other hand, water and ice are specular reflectors and one should refer to their reflectivity, not albedo. Either can appear nearly black when viewed in other than the specular direction, and thus have an albedo significantly less than the total reflectivity, particularly with high angles of incidence.

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