[Originally published 9/16] Greenland glaciers have had a hard time of it lately, what with all the warming and disintegrating, and in their latest edition, the folks at the Times Comprehensive Atlas of the World have decided to illustrate the island’s new look: as you can see above, lots and lots less white. The warming has even created a new island off the east coast: look closely just under the “Gr” in “Greenland Sea,” and you can see the words “Uunartoq Qeqertoq (Warming I.)”
If we are looking at a radically reshaped world in the next hundred years or more, maybe atlases will have to be more like dictionaries from here on out, recording the dynamic nature of their subject matter.
[Update 9/19: Scientists at the UK’s Scott Polar Institute have written a letter to the Times saying that the image above is inaccurate; less ice has melted in the last 15 years than the atlas’s image shows. The atlas’s publishers, HarperCollins, respond that they created the image using data from the US National Snow and Ice Data Center, and that it represents not only changes due to warming but also “much more accurate data and in-depth research” than had previously been available. Regardless of the causes, however, the image doesn’t resemble current satellite images, the Scott Polar group says. Check out a comparison of the images here. What do you think?]
What’s the News: Climate change may have sparked the demise of early Viking settlements in Greenland, according to a new study published online in the Proceedings of the National Academy of Sciences, when temperatures cooled rapidly over several decades. Around the time the Vikings disappear from the island’s archaeological record, temperature appears to have plunged. Nor were the Vikings the only people in Greenland whose fortunes rose and fell with the average temperature, the study suggests. Earlier cold spells may have played a role in the collapse of two previous groups on the island.
The “young sun paradox” just won’t go away. For decades, scientists like Carl Sagan have tried to resolve this mystery of the early solar system—how the newborn Earth stayed warm enough to keep liquid water—but it continues to bob and weave around an answer. In the journal Nature, a team led by Minik Rosing proposes an alternate solution to the leading theory, which relies on the greenhouse effect hypothesis. But don’t expect the debate to end here.
The problem is this: The young Earth received much less heat from the sun. Four billion years ago, a lower solar luminosity should have left Earth’s oceans frozen over, but there is ample evidence in the Earth’s geological record that there was liquid water — and life — on the planet at the time [Space.com]. So what gives? The traditional explanation going back to the 1970s has been that a powerful greenhouse effect, far stronger than the one we experience today, kept the Earth basked in enough warmth to keep water sloshing around the planet’s surface as a liquid and not packed in solid ice. In 1972, Sagan and colleague George Mullen wrote that such an effect would have required intense carbon dioxide concentrations in the atmosphere during that period, the Archaen.
A rare piece of good news about the effects of global warming trickled through the media this weekend, as Dutch researchers announced that Greenland‘s massive ice sheet isn’t melting as quickly as some had feared. Researchers used 17 years of satellite data to measure the seasonal changes to the ice sheet, which covers about 80 percent of Greenland’s surface, and found that the episodes of extremely rapid melting that researchers have observed recently are a transient summer phenomenon.
The melting of the Greenland ice sheet figures into the most troubling global warming doomsday scenarios; if the vast stretch of ice melted completely, it would raise global ocean levels by about 23 feet, swamping island nations and coastal communities. The new study dismisses the idea that such a doomsday could come to pass within a few decades. However, other researchers were quick to say that this study doesn’t answer all the questions about how the ice sheet will behave under shifting climatic conditions.