Microbes washed downstream could fertilize ecosystems, the researchers said, but they needed to be studied much better to identify any potential pathogens. Scientists said the rapid melting of ice sheets from the climate crisis meant glaciers and the unique microbial ecosystems they housed were “dying before our eyes”, leaving researchers scrambling to understand them before they disappear. Some of the microbes may also be a future source of useful biological molecules, such as new antibiotics. The scientists collected surface meltwater from eight glaciers across Europe and North America and from two locations on the Greenland ice sheet. They found tens of thousands of microbes in every milliliter of water. Hundreds of thousands of tons of microbes would be released each year under all future scenarios for global warming, the study found. Photo: Dr Arwyn Edwards/Dr Tristram Irvine-Fynn, Aberystwyth University The data allowed them to estimate that the discarded bacteria and algae would yield an average of 650,000 tonnes of carbon per year for the next 80 years in the Northern Hemisphere, excluding the Hindu Kush Himalayan region, which was not sampled. This estimate assumes a continued moderate increase in CO2 emissions. If carbon emissions are reduced, slowing global warming and ice melt, the mass of microbes released will be reduced by about a third. “We are seeing glaciers dying before our eyes, affecting the microbes that live there, with consequences for us locally and globally,” said Dr Arwyn Edwards, at Aberystwyth University in Wales, and a member of the study team. “The mass of microbes released is huge even with moderate heating.” “We don’t have enough data to understand the value and threat of these organisms. I often get questions about whether a doomsday pathogen is going to melt off the glaciers. I think it’s a very small risk, but it’s not zero risk, so we need a risk assessment for these microbes.” Until recently, very little was known about the many thousands of microbial species that inhabited the surface of the ice. Nearly 1,000 new species were discovered in Tibet’s glaciers in June. A consortium of researchers, the Vanishing Glaciers Project (VGP), is conducting expeditions around the world to collect samples and assess this biodiversity. Professor Tom Battin, at the Swiss Federal Institute of Technology in Lausanne and a member of the VGP, said people should not worry about pathogens emerging from the ice. He also said that most of the ice microbes don’t seem to persist downstream. The most important stories on the planet. Get all the week’s environmental news – the good, the bad and the must-haves Privacy Notice: Newsletters may contain information about charities, online advertising and content sponsored by external parties. For more information, see our Privacy Policy. We use Google reCaptcha to protect our website and Google’s Privacy Policy and Terms of Service apply. Another recent study of viruses in Hazen Lake in Canada, the world’s largest Arctic freshwater lake, showed that the risk of virus spread to new hosts was higher in locations near where large amounts of glaciers were inflowing. The new research, published in the journal Nature Communications Earth and Environment, used surface meltwater samples from four glaciers in the European Alps, as well as glaciers in Canada, Sweden, Svalbard and the western Greenland ice sheet. The study found that hundreds of thousands of tons of microbes would be released each year under all future scenarios for global warming. Bacteria and algae usually contain pigments to protect themselves from damage from sunlight. But these dark pigments absorb sunlight, increasing warming and accelerating the destruction of their frozen habitat.
