Like melting sea ice and glaciers, the frozen sheets that cover lakes are vanishing, too. Lake ice loss has accelerated over the past 25 years, with lakes in the northern hemisphere melting an average of 45 days earlier than they did a century ago.
鈥淭he loss of ice in freshwater systems has consequences that are social, environmental and economic,鈥� says of the Carnegie Institution for Science in Washington DC.
快猫短视频s have only recently started to recognise the important ecological role of lake ice, which provides many natural services: maintaining water quality, supporting biodiversity, retaining carbon and preventing water loss through evaporation. According to a review of research on lakes鈥� winter ice cover by Hampton and her colleagues, rising temperatures threaten all these things, but scientists still don鈥檛 know how this will ultimately affect freshwater systems.
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Both the duration of freezing and the thickness of ice on lakes and other freshwater bodies is decreasing 鈥� and these trends will only worsen in the coming years, according to recent findings. If global air temperatures rise by between 1.5掳C and 3掳C (between 2.7掳F and 5.4掳F), there will be 13 to 24 fewer days of solid ice cover on northern hemisphere lakes, and ice-covered days at lower latitudes could decrease by 80 per cent. Additionally, by 2080, 18 per cent of the world鈥檚 1.4 million lakes that formerly froze throughout the winter will only be intermittently covered in ice.
Around 1.1 billion people live around lakes that freeze, according to calculations by Hampton and her colleagues, and winter ice is important for many local economies. In Sweden, for example, ice fishing generates $880 million annually. And seasonal roads that cross frozen freshwater bodies are a vital lifeline for some isolated communities. In February, four First Nations in Manitoba, Canada declared a state of emergency when insufficient lake and river ice cut off the delivery of essential supplies.
鈥淭his review is the most comprehensive to date on both the ecological and societal consequences of lake ice loss,鈥� says 聽at the University of Colorado Boulder, who wasn鈥檛 involved in the research. 鈥淲hile there are many scientific unknowns, the societal consequences are already here.鈥�
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