One of the Tweet-worthy current events items I've come across in the last couple of days is news that climate scientists say the Arctic ice pack has reached its lowest extent since the satellite records began in 1979. The National Snow and Ice Data Center at the University of Colorado says the Arctic sea ice appears to have reached a season minimum this past Sunday, September 16, of 3.41 million square kilometers (1.32 million square miles). That's half the average seen in the years 1979-2000 (and above, that's a graphic from the NSIDC showing the sea ice extent for September 19).
What does it mean? Here's a decent summary of the basic thinking from today's PBS NewsHour:
The ice is younger and thinner than it was in the 1980s. Of the ice surveyed this summer, the majority was one to two years old and three to five feet thick on average. That's down from 10 to 13 feet thick in 1985.
Losing sea ice also has immediate impacts on Arctic wildlife. Walruses that normally rest on the ice while hunting ocean fish moved ashore by the thousands last year. Arctic seal populations have already declined as a result of disappearing ice. And a 2009 United States Geological Survey estimated that by 2050, the world could lose two-thirds of its polar bears as their ice-dwelling food sources disappear. The ice is also home to delicate microorganisms, which, if lost, could upset the entire Arctic food chain, Meier said.
Ted Scambos, senior research scientist at NSIDC, said that changes in the Arctic's ice and snow are making the Arctic warmer, which may mean major weather and climate changes for the rest of the planet. Sea ice reflects the sun's rays, which helps regulate the planet's temperatures, especially during the summer. Losing the reflective ice surface causes temperatures to rise. If the North Pole is not as cold as it used to be, that has the potential to change wind and weather patterns throughout the Northern Hemisphere.
"But a wider impact may come from the increased heat and moisture that the Arctic is adding to the climate system," Scambos said in a press release yesterday. "This will gradually affect climate in the areas where we live...We have a less polar pole--and so there will be more variations and extremes."
Having read some of the accounts of the sea ice retreat yesterday, I went looking for images of what the Arctic looks like. A favorite resource: NASA, which publishes a bunch of cool images of various Earth features every day. One of the services, called MODIS(MODerate Resolution Imaging Spectroradiometer), includes daily mosaics of the Arctic snapped by NASA satellites. Every time I see these images of Earth from space, the thought that seizes me--or maybe it's more of an emotion--is what an incredibly beautiful place this planet is.
Looking at the Arctic day to day, I wondered whether I could turn the images into a "movie." Well, I could, sort of. I downloaded 185 days worth--from March 20 through September 20--then turned them into a slideshow, saved that as a movie, and uploaded it to YouTube. Here it is:
I will say up front that while the view is breathtaking, the Arctic weather screens the view of precisely what's happening with the ice. It's not as stark as you might expect (and of course, this is just one season we're looking at; there's nothing here to give a comparison to how this scene unfolded 30 years ago).
One note of orientation and explanation: The North Pole is near dead center in the images. Greenland is clearly recognizable at the lower left; Iceland is at the lower center, and Scandinavia and the northern coast of Russia are at the lower right. Siberia dominates the right side of the map (these images show weeks of heavy smoke from fires there). At the top margin, the Bering Strait, where Siberia nearly meets Alaska, is just left of center. Alaska appears inverted at the left, with the Gulf of Alaska at the top left corner.
One more video: This year's Arctic ice melt as presented by NOAA's Environmental Visualization Laboratory: