Around half of the world’s glaciers — a main source of freshwater for 2 billion people — will disappear by 2100 even under the most optimistic plans to rein in global carbon emissions, according to a shocking report published Thursday.
In a new study, published in the journal Science, researchers said every degree our planet warms is important when it comes to protecting glacial ice. If the planet warms by 1.5 degrees Celsius above pre-industrial levels, the most ambitious target scientists have come up with to address climate change, 49% of glaciers are expected to disappear by the end of the century when compared to 2015 levels. If the planet warms by 2.7 degrees Celsius, the expected rise based on climate pledges at the United Nation’s 2021 climate summit, the number of lost glaciers jumps to 68%.
Things only get worse from there.
“If there’s one thing to take away from our study, it’s that every increase in temperature matters,” David Rounce, an assistant professor at Carnegie Mellon University and a lead author of the report, wrote. “We, as a society, have the ability to make a difference to save a considerable amount of glaciers and lower the impacts associated with glacier loss.”
The study used new techniques to study satellite data that helped researchers project how every glacier on the planet will respond to warming scenarios. Those at lower latitudes will be more susceptible to warming, and some areas, including Western Canada, the U.S. and New Zealand could lose 60% to 100% of their glacial mass under higher warming scenarios.
The loss of glaciers, which can stretch for miles like frozen rivers, will directly contribute to sea level rise. The report estimates about 3.5 inches of sea level increase if warming is limited to 1.5 degrees Celsius, 4.5 inches at 2.7 degrees of warming and 5 inches under a dire 3 degrees over pre-industrial levels.
The study includes about 215,000 glaciers, but excludes the massive Greenland and Antarctic ice sheets. Scientists have long said climate change would cause mass losses in ice levels in those regions, too, leading to environmental disruption and far more sea level rise.
The planet’s glaciers have been shrinking for decades, threatening iconic tourist and cultural sites including Glacier National Park in the United States and the last remaining glaciers in Africa. But warming temperatures will directly impact hundreds of millions of people that rely on annual seasons of freeze and glacial melt for their fresh water, like those in the Hindu Kush-Himalayan region and parts of Europe.
The authors warned Thursday that the planet is not on track to keep global warming over pre-industrial levels to 1.5 degrees Celsius, stressing the findings should prompt countries to adopt far more ambitious climate goals to help preserve glacial ice.
“The rapidly increasing glacier mass losses as global temperature increases beyond 1.5C stresses the urgency of establishing more ambitious climate pledges to preserve the glaciers in these mountainous regions,” the paper reads.