Science, Tech & Environment

On a long downward slide, scientists say 2013 was an up year for Arctic Ice

ESA Ice Mission.jpg

Credit: ESA/AOES Medialab

ESA’s Earth Explorer CryoSat mission is dedicated to precise monitoring of changes in the thickness of marine ice floating in the polar oceans and variations in the thickness of the vast ice sheets that blanket Greenland and Antarctica.

“The ice is melting! The ice is melting!”

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(This story is based on a radio interview. Listen to the full interview.)

You might remember the cries from a year or so ago—the widely-reported record drop in Arctic ice cover at the end of the 2012 Arctic melt season in October. It was a huge decline, alarming to some scientists and many climate activists, and like many other news outlets we here atThe World reported on the science and reflected the alarm with which it was being received.

So now that the data is in on the 2013 Arctic melt season, how do things look?

Well, in a surprise to most folks, if not climate scientists themselves, they look exactly the opposite from last year.

Scientists from the European Space Agency confirmed this month that Arctic ice cover at the end of the northern summer was way up, from about 6,000 cubic kilometers in October 2012 to about 9,000 cubic kilometers at the same point in 2013. That’s roughly 50% more ice.

So… does that mean everyone who rang the alarm bells last year about the future of the Arctic were wrong?

Climate change deniers are jumping on the numbers to argue that they were.

But the truth is, well, no such luck.

When you talk about climate change, as with any big global processes, you have to look at the long term. And over the long term, the trend in Arctic ice is still very much downward, with occasional upticks. The 50% jump in end-of-summer ice cover might look remarkable, until you look back to 1980 or so when scientists first started looking at ice mass in the Arctic.

Back then the average ice minimum was 20,000 km3.

So even this year’s big rebound left the Arctic ice minimum less than half as big as three decades ago. Scientists say the average annual minimum these days is down by about 40%.

One scientist put it well in an interview with the BBC: if you were going to grade the Arctic on its ice, last year it got an F, this year—maybe a D.

Of course a D is better than an F. So in the short term, the rebound is good news. A colder Arctic with more ice is generally better for the climate system both in the Arctic itself and in the rest of the world.

It’s good for the Arctic because healthy populations of polar bears and many other Arctic animals need thick, regular ice cover.

And it’s good for the rest of the world for a few important reasons.

One big one is that when there’s less ice, the darker ocean absorbs more solar radiation. That sunlight warms the water, which in turn warms the air, which just feeds back into the whole process of global warming that’s causing the ice to melt in the first place.

So more ice this year means more solar radiation reflected off its white surface back into space, and less warming of the ocean.

Another big concern is something locked up in sediments underneath the Arctic ocean—frozen methane.

As the ocean water warms, it starts to warm those sediments. A little more of that methane seeps out, some of it goes up into the atmosphere where it’s a powerful greenhouse gas, and you get the same kind of thing as with sunlight and open ocean—another feedback loop.

The science on these methane deposits is still very uncertain and hotly debated, but it’s definitely a concern. So even one year of more Artic ice and less warming is a welcome turn of events.

Of course the impact of those two processes is fairly slow and long-term. But there’s another way that the warming Arctic might be having a much more immediate impact. There’s a growing body of research suggesting that the warming Arctic is messing up the polar jet stream that helps move weather systems around the world—how fast it moves, how it carries warm fronts, cold fronts, storms, etc.

Some researchers assert that some of the extreme weather we’ve been experiencing down here in the temperate latitudes in recent years may in part be because warming in the Arctic is causing the polar jet stream to do weird things.

This is also very controversial research, but it’s getting more traction in the climate science community. There’s a growing understanding that, as one Arctic researcher recently put it, what happens in the Arctic doesn’t stay in the Arctic.

OK, so concerned readers (and public radio program hosts) want to know—what can they do to help put a stop to all this warming and melting in the Arctic?

Well, as with everything else related to climate change, it comes down to putting less carbon dioxide and other greenhouse gases into the atmosphere. It’s really the same old list: Drive less, or drive a car that gets better mileage or is powered by renewable electricity. Insulate your house better. Switch your heat/AC and electricity from sources powered by from coal and oil to natural gas, or even better, to sources powered by the sun, the wind, the tides or the earth’s own heat. Eat less meat, and foods grown with fewer fossil fuel inputs like chemical fertilizers. The list is long and growing quickly, and the changes are getting easier to make.

It’s a gigantic battleship that we’ve got to turn around, and the greenhouse pollution we’ve already put into the atmosphere will affect the climate system for generations, but what we do still will make a difference. As individuals and families we can all do little things; as a society we can do more; as a globe we can do more still.

You don’t have to care about climate change and the crisis in the Arctic. But if you do care, find out what you can do, and do it.

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