Arctic Ice Extent Understated Because of "Sensor Drift"

dtjohnson writes "The National Snow and Ice Data Center (NSIDC) has been at the forefront of predicting doom in the arctic as ice melts due to global warming. In May, 2008 they went so far as to predict that the North Pole would be ice-free during the 2008 'melt season,' leading to a lively Slashdot discussion. Today, however, they say that they have been the victims of 'sensor drift' that led to an underestimation of Arctic ice extent by as much as 500,000 square kilometers. The problem was discovered after they received emails from puzzled readers, asking why obviously sea-ice-covered regions were showing up as ice-free, open ocean. It turns out that the NSIDC relies on an older, less-reliable method of tracking sea ice extent called SSM/I that does not agree with a newer method called AMSR-E. So why doesn't NSIDC use the newer AMSR-E data? 'We do not use AMSR-E data in our analysis because it is not consistent with our historical data.' Turns out that the AMSR-E data only goes back to 2002, which is probably not long enough for the NSIDC to make sweeping conclusions about melting. The AMSR-E data is updated daily and is available to the public. Thus far, sea ice extent in 2009 is tracking ahead of 2005, 2006, 2007, and 2008, so the predictions of an ice-free north pole might be premature."

Comments

Re:We only use data that support our hypothesis

[Anonymous Coward]

My father is an environmental engineer. He cleans up some of the stupid crap we have done over the past hundred years. We were having a talk about global warming years ago, before it was a big buzzword. He said to me: "Be careful listening to the global warming experts. If they have devoted their career to global warming and if it turns out not to be true, they don't just lose their job they lose their field of expertise."

Re:How can people expect...

[oodaloop]

Yeah, overall I'd say it's a mixed bag. I was highly skeptical myself until recently when I started reading more about it. I wanted to see the evidence that the Earth was in fact warming. I wanted to see the evidence that said warming was Anthropogenic. And I wanted to see the evidence that this was going to be a bad thing if true. Most of what you see in the mainstream media is how we produce CO2, and how CO2 can heat the planet. But they don't link the two to show that the amount we produce does and has heated the planet and they don't talk specifically about how even a small increase can be disastrous other than a rise in ocean levels. I've read a few books on it, and I'm no longer skeptical and accept that we are causing a rise in temperature on Earth, and that this is generally very very bad.

Despite what this article says, Arctic ice has decreased significantly in recent years. Satellite imagery from as recent as 1979 shows enormously more ice than we see today.

Re:Rocket science?

[AmericanGladiator]

And your argument is nothing more than an ad hominem attack on the poster, which is equally worthless.

Let me argue his point from a logical perspective.

Let's assume that a certain political party makes its hay by promising things to the underclass. They make promises to those who have very little and so the promises don't have to be very big to make them happy.

Now assume that this party wants to stay in power and have a greater number of votes for them in future elections. This party would therefore welcome the idea of a larger underclass. They would potentially do things that would weaken the middle class so that there is a larger lower class and and smaller middle class. If they can put things in place like cap & trade systems for energy emissions, where the wealthy will remain wealthy, but the middle class will suffer, they come out ahead.

It's not so much paranoia in my opinion, but a shrewd understanding of how politicians love power and want to stay in power. In this case, I am referring to democrats as they (to me), seem to want to enact policies that hurt the middle class. Global warming is something they have championed because it helps to further their agenda, not because it necessarily is good for the environment.

Re:How can people expect...

[Freedryk]

I'm a climate scientist--a modeler, in fact. I know C, C++, Fortran, Python, Java, bits of Perl and PHP. I figure I could get a job at Amazon on Google or Microsoft or some other big software shop and be making over $100k. I could certainly do better than what my salary has been: $25k for 2000-2006 (grad school), and for 2007-8 it was $40k (postdoc). Let's say I got a job for $50k/yr--that would be an extra $170k I would have made over the last 8 years.

Let me tell you buddy, I'm not in this for the money.

And if someone could find compelling evidence that indicated global warming wasn't happening, that would be welcomed by the climate science community. New evidence that overturns an old understanding is the holy grail of science.

Re:Rocket science?

[wytcld]

Unfortunately climate data and predictions are apparently more motivated by political beliefs and biases than hard facts.

That's an empty assertion, apparently motivated by the conflict between the conclusions from overwhelming climate data and the writer's ideology.

Where is the sociological data to support it? All these claims about "political beliefs and biases" among climate scientists are working backwards from a desire to reject the conclusions of science to ad hominem attacks on the scientists themselves - attacks which make presumptions about the politics of scientists which are naive in the extreme. A great many - perhaps most - scientists are not political at all. They're too busy with their science to worry about politics outside of their own university departments, and anyway consider most politicians and commentators a bit too stupid to concern themselves with one way or the other.

So where's your data on "political beliefs and biases" among climate scientists? As most of them are funded by governments, can you show an example from any scientific community of a pronounced pattern of biting the hand that feeds it? Consider the scientists funded by drug companies. Do their results cut against their funders?