A century’s worth of data.
That’s how much researchers looked at for a new study — which showed that the world’s glaciers are melting faster than scientists think they ever have before, and that even if global warming stopped today, they would continue to melt.
The observations show that “the rates of early 21st-century [glacial] mass loss are without precedent on a global scale, at least for the time period observed and probably also for recorded history,” according to the study from the World Glacier Monitoring Service, based in Zurich.
The study, published last week in the Journal of Galciology, looked at more than 5,000 measurements since 1850.
The melting is speeding up. Glaciers are now losing mass twice as fast as they were in the period from 1901-1950, three times as fast as in the period from 1851-1900, and four times as fast as in the period from 1800-1850, the researchers found.
And the glaciers will continue to recede, even if global temperatures stabilize, the study’s lead author, Michael Zemp, told Climate News Network. “Due to the strong ice loss over the past few decades, many glaciers are too big under current climatic conditions. They simply have not had enough time to react to the climatic changes of the past,” he said.
In other words, the Earth’s glaciers are melting to keep up with temperature changes that have already occurred.
“In the European Alps, many glaciers would lose about 50 percent of their present surface area without further climate change,” Zemp said.
Efforts to halt global warming at its current level have been met with mixed enthusiasm, particularly among congressional Republicans and the coal industry, who are currently proposing legislation and litigation that would avoid the carbon emissions reductions sought under the newly released Clean Power Plan. In December, world leaders will meet in Paris to discuss — and maybe set — carbon emission reduction goals to keep warming below the 2°C that is generally accepted to be the limit to avoid the most catastrophic effects of climate change.
Glacial melt, which contributes to sea level rise, is one of those dangerous effects. Melting glaciers may even have a reinforcing effect on climate change, according to a study by climate scientist James Hansen, published last month. And rising sea levels will affect a wide swath of the global population. Three-quarters of the world’s large cities are coastal. Rising sea levels are correlated with increases in storm surge, erosion, and inundation, according to Anders Carlson, an Oregon State University glacial geologist and paleoclimatologist.
“It takes time for the warming to whittle down the ice sheets,” he said. “But it doesn’t take forever. There is evidence that we are likely seeing that transformation begin to take place now.” Carlson told ThinkProgress that “we are nearing one degree Celsius warming,” and that the “worst case scenario is what we are already on.”