(Press-News.org) A new study conducted jointly by the Univerisyt of Liege (Belgium) and the University of Reading (England) suggests that 34% of the Antarctic ice shelves could disappear by the end of the century if the planet warms up by 4°C compared with pre-industrial temperatures. This melting could lead to a significant rise in sea levels. This study is published in the journal Geophysical Research Letters.
Since the early 2000s, scientists have observed that the Antarctic ice sheet is losing mass at a rate that is accelerating. The ice sheet is a very thick expanse of ice that can cover an entire continent. There are only two ice sheets on Earth: the Greenland ice sheet, which is limited to the land cover, and the Antarctic ice sheet, which extends beyond the continent into the ocean to form large floating platforms. "These ice shelves act like dams and keep the ice on the continent," explains Christoph Kittel, a researcher at the University of Liege Climatology Laboratory and co-author of the study published in the journal Geophysical Research Letters (1). Without these platforms, huge amounts of ice would flow directly into the ocean, leading to a consequent rise in sea levels."
In summer, the snow on the surface of these platforms melts and water seeps into the small empty spaces in the deep snow layers where it can refreeze and restore the strength of the platform. If the melt is too great, then the excess water seeps deeper into the ice or forms lakes on the surface. The seepage and increased weight of the water as a result of lake formation tends to fracture the ice. And when the ice melt is greater than the snowfall, there is a high risk of platform failure. "The break-up and disappearance of the Larsen B platform in 2002 showed how sensitive these barriers are to melting," explains Ella Gilbert, co-author of the scientific paper and a researcher in the Department of Meteorology at the University of Reading. "In a few days, about 3250 km2 of ice has been dumped into the ocean."
For their study, the researchers used the Regional Atmospheric Model (MAR) developed by the Climatology Laboratory of the University of Liege - one of the best models in the world for studying polar climates. The model allowed them to calculate the evolution of conditions that lead to platform failures in Antarctica under different levels of climate warming ranging from 1.5°C to 4°C. All these scenarios are possible for the end of the century.
"As temperatures rise, intense summer melt events will be repeated and, above all, will become more intense," says Christoph Kittel. The meltwater will no longer be able to be absorbed by the snow to refreeze, but will form lakes and seep deeper into the ice of the platforms, which will lead to break-ups." The study identified platforms where the risk of break-up is high. Four platforms - Larsen C, Shackleton, Pine Island and Wilkins - are therefore considered 'at risk' because of their location and predicted melt.
"If temperatures continue to rise at the current rate, we could see even more platform collapse events in the next few years," says Gilbert. This echoes a previous study by Christoph Kittel, recently published in the journal The Cryosphere (2), which suggests that climate change in Antarctica may have been underestimated in previous IPCC reports for the year 2100. The climate scientists stress the importance of meeting the targets set by the Paris Agreement as soon as possible, which would limit global warming and the risks of destroying Antarctic platforms. "It is important to act quickly, because we are talking about ten years or even 2040 at the very most before the most pessimistic scenario stands out. Limiting global warming is not just good for Antarctica, preserving the ice shelves means reducing the rise in sea level and therefore the impact that this will have on all our lives," conclude the two researchers.
INFORMATION:
Scientific references
(1) Gilbert, E and Kittel C.: Surface melt and runoff on Antarctic ice shelves at 1.5°C, 2°C and 4°C of future warming. Geophysical Research Letters, https://doi.org/10.1029/2020GL091733, 2021
(2) Kittel, C., Amory, C., Agosta, C., Jourdain, N. C., Hofer, S., Delhasse, A., Doutreloup, S., Huot, P.-V., Lang, C., Fichefet, T., and Fettweis, X.: Diverging future surface mass balance between the Antarctic ice shelves and grounded ice sheet, The Cryosphere, 15, 1215-1236, https://doi.org/10.5194/tc-15-1215-2021, 2021
A shared set of systems in the brain may play an important role in controlling the retrieval of facts and personal memories utilised in everyday life, new research shows.
Scientists from the University of York say their findings may have relevance to memory disorders, including dementia, where problems remembering relevant information can impact on the daily life of patients.
Researchers say the findings may also have important implications for the development of a new generation of artificial intelligence systems, which use long-term memory in solving computational problems.
The brain's long-term memory stores are categorised into two: factual memory ...
Researchers at the University of Toronto have found that a calorie labelled is not the same as a calorie digested and absorbed, when the food source is almonds.
The findings should help alleviate concerns that almonds contribute to weight gain, which persist despite the widely recognized benefits of nuts as a plant-based source of protein, vitamins and minerals.
"Nuts have generally been thought of as healthy the last two decades, but the messaging around nuts has often come with a disclaimer that they are high in fat and energy," said John Sievenpiper, ...
Inland waters are an important component of the global carbon cycle and function as active reactors, transporting and transforming large quantities of naturally- and anthropogenically-derived carbon. Previous studies suggest that inland waters are major sources for greenhouse gas emissions to the atmosphere, yet these emissions are poorly constrained (Note 1).
As a primary greenhouse gas that drives global climate change, carbon dioxide (CO2) emissions from inland waters play a key role in assessing global carbon cycle. While most efforts over the last decade have focused on refining the emission flux estimates at the regional and global scales, scientists do not fully understand the responsiveness of regional ...
A recent study finds U.S. companies that have a substantial number of employees in foreign jurisdictions with lower tax rates are more likely than their peers to "artificially" locate earnings in those jurisdictions - and the Internal Revenue Service (IRS) is less likely to challenge these complex tax-planning activities.
"Many politicians seek to encourage domestic employment and discourage sending jobs overseas," says Nathan Goldman, co-author of the study and an assistant professor of accounting in North Carolina State University's Poole College of Management. "To do that, they'll need to address elements of corporate tax policy that effectively encourage ...
Origami may sound more like art than science, but a complex folding pathway that proteins use to determine their shape has been harnessed by molecular biologists, enabling them to build some of the most complex synthetic protein nanostructures to date.
Using EMBL Hamburg's world-class beamline P12 at DESY's PETRA III synchrotron, a team of Slovenian researchers, in collaboration with EMBL's Svergun group, directed powerful X-ray beams at artificial proteins called coiled-coil origami. The proteins were designed to fold into a particular shape based on short modules that interact ...
Smoking cannabis when you're young may increase your risk of developing heart disease later, according to a recent University of Guelph study.
In the first study to look at specific risk indicators for cardiovascular disease (CVD) in young, healthy cannabis users, researchers found subtle but potentially important changes in heart and artery function.
Cigarette smoking is known to affect cardiovascular health, causing changes to blood vessels and the heart. Less is known about the impact of smoking cannabis on long-term CVD risk, even as use of the substance grows in Canada and abroad. Cannabis is the most commonly used recreational substance worldwide after ...
High blood pressure, the most important cause of disease worldwide, accelerates atherosclerosis but the mechanism is unknown. Using gene modified minipigs, researchers from the Centro Nacional de Investigaciones Cardiovasculares (CNIC) and Aarhus University (Denmark), demonstrate that high blood pressure alters the structure of arteries leading to more accumulation of LDL cholesterol and faster development of atherosclerosis. The study has been published in The Journal of the American College of Cardiology (JACC).
Blood pressure-lowering drugs are routinely used to prevent the development of atherosclerosis and heart disease, but the mechanism of this effect is still ...
The detrimental impact of pesticides on non-target organisms is one of the most urgent concerns in current agriculture. Double-stranded RNAs (dsRNAs) represent the most species-specific class of pesticides to date, potentially allowing control of a target pest without effecting other species. The unprecedented target-specificity of dsRNA is due to its nucleotide sequence-specific mode of action that results in post-transcriptional gene silencing, or RNA interference (RNAi), in the target species. The development and field use of dsRNAs, via both the insertion of transgenes into the plant genome and the application ...
The plasticisers contained in many everyday objects can impair important brain functions in humans. Biologists from the University of Bayreuth warn of this danger in an article in Communications Biology. Their study shows that even small amounts of the plasticisers bisphenol A and bisphenol S disrupt the transmission of signals between nerve cells in the brains of fish. The researchers consider it very likely that similar interference can also occur in the brains of adult humans. They therefore call for the rapid development of alternative plasticisers that do ...
MINNEAPOLIS/ST.PAUL (04/12/2021) -- A new probe into the lingering impacts of the COVID-19 pandemic revealed correlations to six unhealthy eating behaviors, according to a study by the University of Minnesota Medical School and School of Public Health. Researchers say the most concerning finding indicates a slight increase or the re-emergence of eating disorders, which kill roughly 10,200 people every year -- about one person every 52 minutes.
U of M Medical School's Melissa Simone, PhD, a postdoctoral research fellow in the Department of Psychiatry and Behavioral Sciences, collaborated with School of Public Health ...
