Publicado: Vie, Enero 25, 2019
Ciencia | Por Aurelio Ontiveros

Greenland ice melting faster than previously thought

Greenland ice melting faster than previously thought

All it takes to melt Greenland's ice sheet is a surface temperature of 1 C and sunlight.

Also, data from the Gravity Recovery and Climate Experiment (GRACE) project launched by the National Aeronautical and Space Administration (NASA) and Germany shows that between 2002 and 2016 Greenland lost around 280 gigatonne ice every year, enough to raise sea levels by 0.03 inches annually.

"By limiting greenhouse gas emissions we will limit warming, and thus also limit how rapidly and intensely Greenland affects our coastal communities through sea level rise", Trusel said. This counters the previously held thought that the biggest contributor to rising sea levels was ice breaking off glaciers.

Using satellite and Global Positioning System data, Bevis and the other researchers discovered that the rate of Greenland's ice loss increased nearly four-fold between 2003 and 2012.

"As far as rate of exchange of ice to oceans is concerned, both mechanisms are essential", said lead author Michael Bevis, a geophysicist at The Ohio State University.

"But now we recognise a second serious problem: increasingly, large amounts of ice mass are going to leave as melt-water, as rivers that flow into the sea".

Antarctica is becoming an increasing concern, however, with ice vanishing at its fastest rate in recorded history. Those chunks then melt and cause sea levels to rise.

Should the entire west Antarctic ice sheet collapse, sea levels would balloon by around 3.5 metres, albeit over a lengthy time frame.

Duchess Kate gets candid about the struggles of motherhood
The organization provides a range of community support for children and families in South London, and is celebrating 150 years of service.

And a big part of the global ice melt issue is the ice of southwest Greenland, which is definitely a point scientists did not think was melting as fast as it is.

The sensitivity of Greenland's ice sheet to a warming atmosphere (due to global warming) can perhaps be viewed as a "ray of hope", said Luke Trusel, a professor in the department of geology at Rowan University who was not part of the study.

Researchers say the ice rate loss across Greenland has increased four-fold since 2003, which they say will lead to a greater sea level rise.

The findings could have serious implications for coastal USA cities, including NY and Miami, as well as island nations that are particularly vulnerable to rising sea levels. When it's "combined with man-made global warming, though, the effects are supercharged", he said. It's because the atmosphere is, at its baseline, warmer.

The researchers also found that a good amount of this melting occurred in south-west Greenland, which is new as it's not a glacier-rich area.

The culprit appears to be climate change, which combines with a natural air-current phenomenon - the North Atlantic Oscillation - to pummel Greenland with warm air. "And in the case of Greenland, global warming has brought summertime temperatures in a significant portion of Greenland close to the melting point, and the North Atlantic Oscillation has provided the extra push that caused large areas of ice to melt".

"The continent of Antarctica has been losing about 118 gigatons of ice per year since 2002, while the Greenland ice sheet has been losing an estimated 281 gigatons per year". If the sea level rose even by 0.5 meters relative to sea level at the turn of the century, this would cause catastrophic damage near coastlines all over the world.

Me gusta esto: