From The Science is Settled Department. Environmental activists and climate scientists on the AGW gravy train are so desperate to keep the scare afloat that they will find evidence of climate-induced changes in our planet wherever they look.
Everything can be attributed to climate change – it is the unfalsifiable hypothesis to end all unfalsifiable hypotheses. Once our scientist finds a plausible explanation that links a particular phenomenon (freshening of the Arctic waters, for example) to a man-made cause (melting sea ice caused by global warming, for example), he/she can stop looking for any other.
Especially when the consequences are potentially so dramatic – changes in salinity are thought to affect a major ocean current, the North Atlantic Conveyor, which, if interrupted, could “flip” the climate past a “tipping point” into a new Ice Age. They even made a film about it, The Day After Tomorrow, in which the special effects team went completely overboard to create the most terrifying images of what “might” happen if you keep driving your SUV and Australia doesn’t pass the carbon tax legislation:
Faced with such a possibility, who in their right mind could possibly disagree with taking urgent and drastic action to “tackle climate change”? Once the AGW box is ticked, job done.
Except that if our scientist had behaved as a proper scientist should, he/she may have looked deeper, and found that there might be other, more likely or convincing explanations. But taking that path runs the risk of missing out on the AGW angle, which would be a disaster for PR and funding. So that job is put on hold. For a while. Until the day after tomorrow, perhaps.
At least someone was brave enough to do it, however:
A new NASA and University of Washington study allays concerns that melting Arctic sea ice could be increasing the amount of freshwater in the Arctic enough to have an impact on the global “ocean conveyor belt” that redistributes heat around our planet.
Lead author and oceanographer Jamie Morison of the University of Washington’s Applied Physics Laboratory in Seattle, and his team, detected a previously unknown redistribution of freshwater during the past decade from the Eurasian half of the Arctic Ocean to the Canadian half. Yet despite the redistribution, they found no change in the net amount of freshwater in the Arctic that might signal a change in the conveyor belt.
The team attributes the redistribution to an eastward shift in the path of Russian runoff through the Arctic Ocean, which is tied to an increase in the strength of the Northern Hemisphere’s west-to-east atmospheric circulation, known as the Arctic Oscillation. The resulting counterclockwise winds changed the direction of ocean circulation, diverting upper-ocean freshwater from Russian rivers away from the Arctic’s Eurasian Basin, between Russia and Greenland, to the Beaufort Sea in the Canada Basin bordered by the United States and Canada. The stronger Arctic Oscillation is associated with two decades of reduced atmospheric pressure over the Russian side of the Arctic. Results of the NASA- and National Science Foundation-funded study are published Jan. 5 in the journal Nature.
“Changes in the volume and extent of Arctic sea ice in recent years have focused attention on melting ice,” said co-author and senior research scientist Ron Kwok of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., which manages Grace for NASA. “The Grace and ICESat data allow us to now examine the impacts of widespread changes in ocean circulation.”
Kwok said on [the] whole, Arctic Ocean salinity is similar to what it was in the past, but the Eurasian Basin has become more saline, and the Canada Basin has freshened. In the Beaufort Sea, the water is the freshest it’s been in 50 years of record keeping, with only a tiny fraction of that freshwater originating from melting ice and the vast majority coming from Russian river water.
“To better understand climate-related changes in sea ice and the Arctic overall, climate models need to more accurately represent the Arctic Oscillation’s low pressure and counterclockwise circulation on the Russian side of the Arctic Ocean,” Morison added. (source)
You’re saying the models aren’t perfect? Who’d have thought.
Link to Nature abstract here.
(h/t The Register)