Scientists have used information from satellites to reveal that ice melting in Antarctica has not only raised sea levels by 7.6mm since 1992, but almost half of this rise occurred in the last five years.
An international team of researchers led by Andrew Shepherd from the University of Leeds, UK, and Erik Ivins from NASA’s Jet Propulsion Laboratory (JPL), conducted a study that led to a complete picture of how Antarctica’s ice sheet is changing, revealing that prior to 2012 Antarctica was losing 76 billion tonnes of ice a year. The ice melting in Antarctica was causing sea levels to rise at a rate of 0.2mm a year.
Since 2012 however, Antarctica has been losing ice three times as fast – between 2012 and 2017, Antarctica has lost 219 billion tonnes of ice a year, raising sea levels by 0.6mm annually.
How has this research contributed to our understanding of climate change?
The information from the research has been key to understanding how climate change is affecting the most remote part of the planet and how this will change the rest of the world.
Shepherd said: “We have long suspected that changes in Earth’s climate will affect the polar ice sheets. Thanks to the satellites that our space agencies have launched, we can now track their ice losses and global sea-level contribution with confidence.
“According to our analysis, there has been a step increase in ice losses from Antarctica during the past decade, and the continent is causing sea levels to rise faster today than at any time in the past 25 years.”
Which satellites contributed to the research around ice melting in Antarctica?
Several different missions were used in this assessment, with the European Space Agency’s (ESA) CryoSat and the Copernicus Sentinel-1 mission being particularly useful to the study.
ESA says that the CryoSat carries a radar altimeter and is designed to measure changes in in height of ice, which is then used to calculate changes in ice volume. It is also designed to measure changes around the margins of ice sheets where ice is calved as icebergs.
The two-satellite Sentinel-1 radar mission, which is used to monitor ice motion, can image Earth regardless of the weather or time of day or night – which is essential during the dark polar winters.
ESA’s Director of Earth Observation Programmes, Josef Aschbacher, commented, “CryoSat and Sentinel-1 are clearly making an essential contribution to understanding how ice sheets are responding to climate change and affecting sea level, which is a major concern.”