Climate in Context: August 19, 2010
By Michael D. Lemonick and Alyson Kenward
And Now: Antarctic Sea Ice Update
Yesterday we told you that the sea ice coverage in the Arctic is currently running well below average, although not quite in record territory. Today, let’s flip the world upside down and look at Antarctica – what’s going on with sea ice down there? (Keep in mind that although it’s summer in the Arctic, it’s winter in the Southern Hemisphere).
Well, according to a recent paper in the Proceedings of the National Academy of Sciences, an increase in Southern Ocean sea ice area that has been going on for three decades might come to an end, soon-ish; computer models project that global climate change could lead to declining sea ice surrounding Antarctic by the end of the century, if not earlier.
That Antarctic sea ice coverage has grown during the last 30 years doesn’t contradict the global trend of rising temperatures. In fact, warmer global temperatures have brought more moisture into the air, which has consequently increased precipitation in some parts of the world. And near the South Pole, of course, the temperatures are still cold enough that the extra precipitation falls as snowfall, which accumulates onto ice cover and helps shield it from solar radiation. Other air and ocean cycles have combined to build up Antarctic sea ice, in stark contrast to conditions in the Arctic.
As global temperatures climb even higher, however, much of that Antarctic precipitation is bound to...
Climate in Context: August 18, 2010
Arctic Ice Update
Every winter, the surface of the Arctic Ocean freezes pretty much solid (or, more precisely, the surface freezes), Every summer, some of that ice melts to expose open water — and for the past several decades, the amount of open water in late summer has gotten gradually, though somewhat erratically, larger. The biggest meltback was in 2007, and since then, the summer ice has rebounded slightly. It hasn’t been much of a rebound, though. During the summers of 2008 and 2009, the area covered by ice in mid-September (the annual low point) was a little more than in 2007, although still significantly less than the 1979-2000 average.
Now the National Snow and Ice Data Center (NSIDC) has come in with its latest report: as of two days ago, the ice at the top of the world covered about 5.95 million square kilometers of sea — about a half-million more than at this point in the summer of 2007, but about one and a half million less than what should be there at this point based on the 1979-2000 average.
On the chart below, the black line shows the long-term average; the dotted line is the record melt year of 2007, and the blue line represents this year so far. You can also see that only 2007 and 2008 had less ice than we’ve got this year. It’s the kind of “rebound” you’d expect if you dropped a half-deflated basketball on the gym floor.
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Arctic sea ice extent during the 2007-2010 melt seasons (... |
Climate in Context: August 17, 2010
Editor's Note: This is the first installment of what will become daily, quick-hitting blog posts that will cover climate science and energy developments from our nonpartisan (yet still entertaining) perspective.
Coal Ash Ruined My Sunday Night
Shouldn’t Sunday night, by default, be relaxing? After all, it’s the best time to recover from a fun-filled weekend and to prepare for the busy workweek ahead. Unfortunately, anyone who caught this Sunday’s repeat episode of “60 Minutes” probably wasn’t left with any calm feelings. In a segment titled "Coal Ash: 130 Millions Tons of Waste", correspondent Lesley Stahl informed viewers that there is virtually no regulation of the staggering amount of toxic waste byproduct known as coal ash that is generated each year in the burning of coal for electricity in the U.S.
After listing off the poisonous metals that are concentrated in coal ash, including arsenic, mercury, cadmium, thallium, selenium and lead, Stahl pointed out the careless ways in which coal companies dispose of it all – none of it made for an easy Sunday night. Scientists still need to figure out exactly how toxic coal ash is, but Stahl says the EPA is lagging behind with instituting regulations based on existing knowledge.
Stahl seems to have missed the mark on one very important point, however. When speaking with Jim Roewer, a coal lobbyist, about how 48 percent of electricity in America comes from coal, Stahl says, “we can’t get rid...
