Surface area meltwater flowing towards the ocean through a channel in Greenland. Credit: Ian Joughin
International warming has actually triggered extreme ice melting events in Greenland to become more intense and frequent over the past 40 years, raising sea levels and flood risk worldwide, finds new research involving University College London (UCL) academics.
Over the previous years alone, 3.5 trillion tonnes of ice has melted from Greenlands surface and flowed into the ocean– adequate to cover the UK with around 15m of meltwater, or all of New York City with around 4500m.
Released previously this month in Nature Communications, the new study is the very first to use satellite data to spot this phenomenon– referred to as ice sheet overflow– from space.
Funded by the European Space Agency (ESA) as part of its task Polar+ Surface Mass Balance Feasibility, the research study utilized measurements from the ESAs CryoSat-2 satellite objective, using estimates of surface area elevation modification over time.
One of the extremely couple of satellites orbiting with 2 degrees of the worlds poles, CryoSat-2 has actually supplied researchers with a long history of data no other spacecraft could reach considering that its launch over 11 years earlier, transforming scientists capability to study the polar areas. It remains crucial to research and understanding vital to decision-making on the worlds health.
Research study co-author Lin Gilbert (UCL Mullard Space Science Laboratory) said: “Observations reveal that extreme melt events in Greenland have actually become more frequent and more intense– in addition to more irregular– which is an international problem. Monitoring from area allows us to cover the whole of Greenland (and almost all Antarctica) repeatedly, which cant be done by teams on the ground. This is the novice run-off has ever been measured straight from area– permitting us to remotely observe hard-to-explore areas of the ice sheets and use these observations to form an improved understanding of why this is happening and what we can do about it in future.”.
The global group of scientists discovered that over the past four decades Greenlands meltwater runoff has increased by 21%– and has become 60% more irregular from one summertime to the next.
The findings revel that in between 2011 and 2020 increased meltwater runoff from Greenland raised the worldwide sea level by one centimeter– increasing the danger of flooding worldwide and disrupting marine environments in the Arctic Ocean. Rising water level can likewise change patterns of ocean and climatic circulation that impact weather condition conditions around the world.
One third of this rise was produced in simply 2 summertimes– 2012 and 2019– when severe weather resulted in record-breaking levels of ice melting not seen in the past 40 years.
The research study shows that during the previous decade, overflow from Greenland has averaged 357 billion tonnes of ice melt per year– equating to nearly 1 millimeter of global sea level rise– reaching an optimum of 527 billion tonnes in 2012, when modifications in atmospheric patterns triggered abnormally warm air to sit over much the ice sheet.
These changes are associated to extreme weather condition events such as heatwaves, which have ended up being more regular and are now a significant cause of ice loss from Greenland.
Lead author Dr Thomas Slater (University of Leeds) said: “As weve seen with other parts of the world, Greenland is likewise vulnerable to an increase in extreme weather condition occasions. As our environment warms, its affordable to anticipate that the circumstances of severe melting in Greenland will occur more frequently– observations such as these are an important step in assisting us to enhance climate models and much better anticipate what will occur this century.”.
” There are, nevertheless, reasons to be optimistic. We understand that setting and meeting meaningful targets to cut emissions might minimize ice losses from Greenland by an aspect of 3, and there is still time to accomplish this.”.
The study observations can also be utilized to confirm how climate models mimic ice sheet melting, allowing improved predictions of how much Greenland will raise the worldwide water level in future as severe weather condition occasions end up being more common.
Study co-author Dr. Amber Leeson (Lancaster University) said: “Model approximates suggest that the Greenland ice sheet will contribute in between about 3– 23cm to worldwide sea level increase by 2100. This prediction has a large range, in part since of uncertainties associated with mimicing complex ice melt procedures, including those associated with severe weather condition.
” These brand-new spaceborne estimates of overflow will assist us to understand these complex ice melt processes better, enhance our capability to model them, and hence allow us to improve our estimates of future sea level increase.”.
For more on this research study, see Increased Global Flood Risk Due to Intense Frequency of Extreme Ice Melting in Greenland.
Referral: “Increased variability in Greenland Ice Sheet overflow from satellite observations” by Thomas Slater, Andrew Shepherd, Malcolm McMillan, Amber Leeson, Lin Gilbert, Alan Muir, Peter Kuipers Munneke, Brice Noël, Xavier Fettweis, Michiel van den Broeke and Kate Briggs, 1 November 2021, Nature Communications.DOI: 10.1038/ s41467-021-26229-4.