Melting of small glaciers could add 10 inches to sea level

A new review of glacier research data paints a picture of a future planet with much less ice and much more water. Glaciers around the world are expected to lose between 18% and 36% of their mass by 2100, which would result in a sea level rise of nearly 10 inches.

This review is the most comprehensive global comparison ever made on glacier simulations.

"The clear message is that there is a mass loss – a substantial mass loss – worldwide," said lead author Regine Hock, of the Alaska Fairbanks Geophysical Institute University. .

The expected ice loss varies from one region to another, but the trend is obvious.

"We have more than 200 computer simulations, and they all say the same thing.Even if there are some differences, it's really consistent," Hock said.

This is the only comprehensive and systematic attempt to date to compare global glacier models and their projections. The document is part of GlacierMIP, an international project to compare glacier research to understand changes in glaciers and their contributions to sea level rise.

The Hock study compared 214 glacier simulations from six research groups around the world and "all describe the same chart," Hock said.

These groups linked their own studies to more than 25 climate models using a series of climate scenarios. These scenarios are based on several different trajectories for greenhouse gas concentrations and atmospheric conditions adopted by the Intergovernmental Panel on Climate Change, called representative concentration pathways, called by CRP scientists. Currently, the planet is moving toward the highest estimates of greenhouse gas concentrations.

Hock and Andrew Bliss, a former postdoctoral researcher at the Geophysical Institute, and other authors, reviewed the data and the results of these studies to develop a coordinated approach to understanding ice loss.

They examined the mass variations of more than 200,000 glaciers around the world, representing an area equivalent to that of Texas. The study does not include the vast expanses of ice from Greenland or Antarctica, whose behavior is different from that of mountain and terrestrial glaciers and which require unique modeling methods.

The results indicate that smaller glaciers could play a much larger role in sea-level rise than previously thought. Most research has focused on the ice caps of Greenland and Antarctica, because of their size and importance, but the effect of smaller glaciers is considerable.

"We confirm that they actually contribute to sea level rise," Hock said.

For example, the 25,000 glaciers of Alaska will lose between 30% and 50% of their mass by the end of the century. Once this is done, Alaska will be the largest regional regional sea level contributor in the Northern Hemisphere, except for Greenland.

"Globally, by 2100, the sea level only rises by almost 10 inches, but only small glaciers, while everyone thinks that it is only about 10 degrees. 39, Antarctica and Greenland, "Hock said. "But these relatively small glaciers in the world have a huge impact."

The document was published in Glaciology Journal.