Tell a global-warming skeptic that Arctic sea ice receded this year to a record low in the era of satellite measurement, and he might point to the Antarctic as evidence that all is not as it seems. Ice down there recently reached a 33-year high (it's early spring in Antarctica). But it's an apples-oranges comparison, writes Justin Gillis in The New York Times blog Green.
In reality, the trends in Antarctic sea ice are pretty small compared to what’s happening in the Arctic. ...
In Antarctica, when winter sets in and the sun drops low in the sky, sea ice can grow unimpeded over the huge ocean surface. But then, in contrast to the historical situation in the Arctic, about 80 percent of the Antarctic ice melts in the summer. So the Antarctic ice has always come and gone in an annual rhythm. Most of it does not hang around to reflect sunlight back to space at the time of year when Southern Hemisphere sunlight is strongest.
Read more at The New York Times: Running the numbers on Antarctic sea ice