Ice is disappearing across the planet at an increasing rate, according to a study that shows 28 trillion tonnes were lost between 1994 and 2017.
Scientists found that the rate of melting increased from 0.8 trillion tonnes per year in the 1990s to 1.3 trillion tonnes in 2017.
The total lost during this period equates to a 100m thick ice sheet covering the whole of the UK.
It contributed up to 3.5 cm to global sea level during this period, increasing the risk of flooding in coastal communities and threatening to wipe out precarious habitats.
The increase in ice loss was triggered by global warming, with more than two-thirds of the total attributable to rising atmospheric temperatures (0.26 ° C per decade since the 1980s) and 32% to rising temperatures. ocean temperatures (0.12 ° C per decade).
According to the study – the first survey of global ice loss using satellite data – there was a 65% increase in the rate of ice loss over the 23-year period, mainly due to sharp increases in losses due to the polar caps in Antarctica and Greenland.
“Although every region we studied lost ice, the losses from the Antarctic and Greenland ice caps accelerated the most,” said lead author Dr Thomas Slater, a researcher at the Center of Leeds polar observation and modeling.
“The ice caps now follow the worst scenarios of global warming defined by the Intergovernmental Panel on Climate Change. Rising sea levels on this scale will have very serious impacts on coastal communities during this century.
The investigation covered 215,000 mountain glaciers spread around the planet, the polar ice caps of Greenland and Antarctica, the ice shelves floating around Antarctica and sea ice drifting in the oceans. Arctic and Southern.
The largest losses were from Arctic sea ice (7.6 trillion tonnes) and Antarctic ice shelves (6.5 trillion tonnes), both of which float in the polar oceans.
Half of all losses came from land ice – including 6.1 trillion tonnes from mountain glaciers, 3.8 trillion tonnes from the Greenland ice sheet and 2.5 trillion tonnes from the Antarctic ice sheet. These losses have raised global sea level by 35 mm, and it is estimated that around 1 million people are at risk of being displaced for every centimeter of sea level rise.
Dr Isobel Lawrence, a researcher at the Leeds Center for Polar Observation and Modeling, said: “One of the key roles of arctic sea ice is to reflect solar radiation back into space, which helps keep cool arctic. As sea ice shrinks, more solar energy is absorbed by the oceans and atmosphere, causing the Arctic to warm faster than anywhere else on the planet.
“Not only does this accelerate the melting of sea ice, but it also worsens the melting of glaciers and ice caps, which causes sea levels to rise.”
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Glaciers contributed nearly a quarter of global ice loss during the study period, although they only store 1 percent of Earth’s total ice volume.
Ines Otosaka, co-author of the report and doctoral researcher, said: “In addition to contributing to average sea level rise, mountain glaciers are also essential as a freshwater resource for local communities. .
“The receding glaciers around the world are therefore of crucial importance both locally and globally.”
The research, conducted by the University of Leeds with support from the University of Edinburgh, University College London and data scientists Earthwave, was funded by the UK Natural Environment Research Council and is published in the journal of the European Geosciences Union. The cryosphere. A pre-print of the research was published last August.
