Cooler August slows melting in Arctic

The orange line indicates a median ice extent from 1981-2010, while the white areas represent current ice cover. (National Snow and Ice Data Center)
Jenna Ladd | September 27, 2017

The summer melting period has come to an end in the Arctic, and ice cover is at not quite as minimal as scientists had predicted.

Arctic sea ice reached its seasonal minimum extent of 1.79 million square miles on September 13, the eighth lowest of a 38-year satellite record.

The Arctic saw its record minimum ice coverage in 2012 and officials from the U.S. National Snow and Ice Data Centre (NSIDC) were expecting lows after this summer to near record lows, but there was a twist in the plot. August brought more cloud cover and lower temperatures to the region and slowed melting.

Still, the 2017 ice cover minimum was 610,000 square miles below the minimum average recorded between 1981 and 2010. In an interview with the Guardian, Ted Scambos of NSIDC noted that Arctic ice melt has been linked to heatwaves, floods and extreme winters in many parts of the world.

Scambos said that although there is some variation from year to year, “The Arctic will continue to evolve towards less ice. There’s no dodging that.”

Sea levels rising faster than previously expected

These signs indicate how the coast line is expected to move inward at Cottesloe Beach in Perth, Australia. (go_greener_oz/Flickr)
These signs indicate how the coast line is expected to move inward at Cottesloe Beach in Perth, Australia. (go_greener_oz/Flickr)

Nick Fetty | January 16, 2015

A new study by researchers at Harvard University and Rutgers University finds that the earth’s sea levels are currently rising at faster rate than in the past.

The study – published in this week’s edition of the journal Nature – found that between 1900 and 1990 projected sea level increases were overestimated by as much as 30 percent. The original estimates expected sea levels to rise between 1.5 and 1.8 millimeters per year during most of the 20th century while the actual figure was closer to 1.2 millimeters annually. Throughout the entire 20th century sea levels rose by about five inches, an inch less than the previous estimate of six inches. This increase in sea levels during the 20th century amounts to enough water to fill three billion Olympic-sized swimming pools.

The report also points out that previous estimates for sea levels rises after 1990 are now estimated to be higher than previously expected. Since 1990 sea levels have been rising by about 3 millimeters per year much of which can be attributed to the “quickening thaw of ice.”

Prior to the advent of satellite technology, sea levels were monitored using tide gauges which were “unevenly dotted around the coastlines of the world.” Researchers said that this old method did not include measurements from non-coastal parts of the ocean and that this led to the overestimated figures.