Drone surveys have revealed erosion of coastal permafrost in the Arctic — up to 3 feet a day. Researchers reported Friday that the recent rate of erosion is six times higher than the historical rate.
Meanwhile, the Arctic just saw the hottest May on record, with temperatures in northwest Russia hitting a remarkable 84 degrees Fahrenheit (29 degrees Celsius). Global warming is driving Arctic sea ice to near-record lows, which in turn is driving ever-worsening summer heat waves in the southern United States, according to another new study.
In the first study, a team led by University of Edinburgh scientists flew drone-mounted cameras over a section of permafrost coastline in the Canadian Arctic.
They found that during a 40-day period in the summer of 2017, the coast had retreated a remarkable 47 feet — with daily rates of collapse sometimes exceeding 3 feet.
“Big chunks of soil and ground break off the coastline every day, then fall into the waves and get eaten away,” co-author Dr. Isla Myers-Smith, a University of Edinburgh geoscientist, explained.
This rate of erosion was more than six times greater than the historical average experienced in the previous half century.
The permafrost, or tundra, is soil that stays below freezing (32 degrees Fahrenheit) for at least two years. Thawing permafrost is a dangerous amplifying feedback loop for global warming because the global permafrost contains twice as much carbon as the atmosphere does today .
As the permafrost melts, it releases heat-trapping carbon dioxide and methane, and as the coastline disintegrates and erodes, more and more permafrost will be exposed to the warming air and water.
This means, as the planet continues to warm, more permafrost will erode and melt, releasing even more greenhouse gases in a continuous feedback loop.
A 2017 study found the Alaskan tundra is warming so quickly it had become a net emitter of CO2 ahead of schedule. That study was the first to report a major portion of the Arctic had already become a net source of heat-trapping emissions.
Such ice loss is a key reason climate models have long predicted that human-caused warming would be at least twice as fast in the Arctic as elsewhere. When highly reflective sea ice melts due to higher temperatures, it is replaced by the dark blue sea which absorbs more solar energy, leading to more melting.
A study released last week in the Journal of Geophysical Research found that loss of Arctic sea ice is making extreme heat waves more likely. The study concludes that “low summer sea ice in Hudson Bay is statistically linked to an increased frequency of summer U.S. heat waves,” especially in the U.S. Southeast and southern Plains.
The study also finds that the melting sea ice is weakening the jet stream. A weaker jet stream causes summer weather systems to stall, leading to longer and stronger heat waves — and other extreme events, as recent studies have reported.
Back in December, the annual Arctic Report Card from the National Oceanic and Atmospheric Administration (NOAA) noted that “Growing atmospheric warmth in the Arctic results in a sluggish and unusually wavy jet-stream that coincided with abnormal weather events in both the Arctic and mid-latitudes.”
What happens in the Arctic does not stay in the Arctic. Unless we start cutting carbon pollution sharply and rapidly, we can expect Arctic temperatures to soar in the coming decades, bringing ever worsening extreme weather to this country.