Over the last three decades, the rate of global ice loss has been increasing exponentially. In 1994, the planet was losing 800 billion tonnes every year. By 2017, the rate was 1,300 billion tonnes – a 63 percent increase in just 23 years.
These findings, reported in the journal The Cryosphere, suggest that the total loss of ice over the survey period was about 28 trillion tonnes. To picture that, it's the equivalent of a block of ice 100 meters thick (330 feet) the size of the UK, or Michigan. The steep rise in ice loss comes mainly from Greenland and Antarctica.
“Although every region we studied lost ice, losses from the Antarctic and Greenland ice sheets have accelerated the most,” lead author Dr Thomas Slater from the University of Leeds said in a statement.
“The ice sheets are now following the worst-case climate warming scenarios set out by the Intergovernmental Panel on Climate Change (IPCC). Sea-level rise on this scale will have very serious impacts on coastal communities this century.”
The data collected suggests that half of all losses were from ice on land. This includes a staggering 6.1 trillion tonnes lost from mountain glaciers, 3.8 trillion tonnes from the Greenland ice sheet, and 2.5 trillion tonnes from the Antarctic ice sheet. The polar regions have also experienced dramatic sea ice loss.
The biggest losses seen in the survey were from Arctic sea ice, which saw losses of 7.6 trillion tonnes in the 23-year period, and Antarctic ice shelves estimated to have lost 6.5 trillion tonnes. This major reduction has grave consequences for the entire planet and the threat of sea-level rise.
“Sea ice loss doesn't contribute directly to sea level rise but it does have an indirect influence. One of the key roles of Arctic sea ice is to reflect solar radiation back into space which helps keep the Arctic cool,” co-author Dr Isobel Lawrence added.
“As the sea ice shrinks, more solar energy is being absorbed by the oceans and atmosphere, causing the Arctic to warm faster than anywhere else on the planet. Not only is this speeding up sea ice melt, it's also exacerbating the melting of glaciers and ice sheets which causes sea levels to rise.”
The ice melt over the last few decades led to an increase of 35 millimeters of sea-level rise. This might seem like a small amount but for every centimeter of increase, there are a million people at risk of losing their houses. An increase in sea level also makes storm surges more likely to occur.
It's not just coastal communities at risk. Glaciers provide freshwater to communities globally. Ice loss will also put these communities at risk.