In a recent research, a team of scientists have published that Antarctica is experiencing a sudden increase in ice loss which is causing small changes in the gravitational field of the Earth. Since 2009, multiple glaciers along a vast coastal expanse have disappeared in the ocean.
“To date, the glaciers added roughly 300 cubic km of water to the ocean. That’s the equivalent of the volume of nearly 350,000 Empire State buildings combined,” a lead study author Bert Wouters at the University of Bristol said.
“The fact that so many glaciers in such a large region suddenly started to lose ice came as a surprise to us. It shows a very fast response of the ice sheet: in just a few years the dynamic regime completely shifted”, added Bert.
The changes were detected by the CryoSat-2 satellite, operated by the European Space Agency.
The ice loss in the region is so large that it is causing small changes in the gravity field of the Earth. Such a change can be detected by another satellite mission, the Gravity Recovery and Climate Experiment (GRACE).
In the last two decades, the ice shelves in the region have lost almost one-fifth of their thickness, thereby reducing the resisting force on the glaciers.
“To pinpoint the cause of the changes, more data need to be collected. A detailed knowledge of the geometry of the local ice shelves, the ocean floor topography, ice sheet thickness and glacier flow speeds are crucial to tell how much longer the thinning will continue,” Wouters concluded.
Permafrost in Northern Arctic can potentially become a permanent source of Carbon
It was previously thought to be safe from the effects of Global Warming
Rising temperature in the Arctic can cause severe carbon emissions
Permafrost in the coldest northern Arctic — formerly thought to be at least temporarily shielded from global warming by its extreme environment — could thaw enough to become a permanent source of carbon to the atmosphere in a few decades, warns a NASA-led study. This will happen in this century, with the peak transition occurring in 40 to 60 years, said the study.
Permafrost is soil that has remained frozen for years or centuries under topsoil. It contains carbon-rich organic material, such as leaves, that froze without decaying, NASA said in a statement on Tuesday.
As rising Arctic air temperatures cause permafrost to thaw, the organic material decomposes and releases its carbon to the atmosphere in the form of the greenhouse gases carbon dioxide and methane.
The researchers calculated that as thawing continues, by the year 2300, total carbon emissions from the coldest northern Arctic will be 10 times as much as all human-produced fossil fuel emissions in 2016.
Warmer, more southerly permafrost regions will not become a carbon source until the end of the 22nd century, even though they are thawing now, said the study led by scientist Nicholas Parazoo of NASA’s Jet Propulsion Laboratory in Pasadena, California.
That is because other changing Arctic processes will counter the effect of thawing soil in these regions.
The finding that the colder region would transition sooner than the warmer one came as a surprise, according to Parazoo. The researchers used data on soil temperatures in Alaska and Siberia and a numerical model that calculates changes in carbon emissions as plants grow and permafrost thaws in response to climate change.
They assessed when the Arctic will transition to a carbon source instead of the carbon-neutral area it is today — with some processes removing about as much carbon from the atmosphere as other processes emit.
They divided the Arctic into two regions of equal size, a colder northern region and a warmer, more southerly belt encircling the northern region. There is far more permafrost in the northern region than in the southern one.
Over the course of the model simulations, northern permafrost lost about five times more carbon per century than southern permafrost.
The southern region transitioned more slowly in the model simulations, Parazoo said, because plant growth increased much faster than expected in the south.