Saturday, October 31, 2009

Back to the real world, Part 1

Greenland is melting.

Well, not exactly, the land isn't of course, just the ice that's on top of it. And of course that ice is always melting, always has been, as glaciers move oh-so-slowly to the sea, and slowfall replenishes them.

So what's the big deal? Simple: It is - or, again to be more exact, the glaciers are - melting faster than they used to.
[T]he remarkable thing about the Jakobshavn Isbrae[, the most productive glacier in the northern hemisphere, shedding 35 billion tons of ice a year] – and nearly all of Greenland’s glaciers, and most of the glaciers in the world – is how fast those outward waves are flowing now.
In 2002, the Jakobshavn Isbrae was moving at the rather brisk clip (for a glacier) of 20 meters a day. Now, it's moving 40 meters a day and dumping twice as much ice into the fjord. Another large glacier, the Hellheim glacier, accelerated from 8km a year in 2000 to 11km a year in 2005 - and the speed is still increasing.
The reason the glaciers are speeding up is simple: Greenland is getting warmer. Jacqueline McGlade, director of the European Environment Agency, says: “The amount of ice that is being lost is far more than we thought. Greenland is warming faster than the computer models predicted, and that is a worry.” The Arctic has warmed at three times the rate of the rest of the world in the past 100 years, and temperatures continue to rise. Ola Johannessen, chief of Norway’s Nansen Environmental and Remote Sensing Centre, has worked on ice for more than 30 years. He has never seen anything like the current situation. “There is no doubt that what we are seeing is the result of global warming.”
That warming is already having an impact, not only on the glaciers but on the people of Greenland as the hunting on which they depend declines: Traditional quarry of polar bears and walruses struggle against shrinking habitat and the hunting season shortens because for months the ice is no longer thick enough to reliably bear the weight of their dogsleds and skidoos.

Greenlanders are not likely to be the worst affected by warming, as what they lose in hunting they may well regain in farming. Still, it is yet another example of how global warming is having an impact right now rather than off in the future.

But what's to worry? According to all the nanny-nanny naysayers, average world temperatures are actually declining! It's global cooling!

Which of course they're not and it isn't. We knew that already, but now it's been demonstrated mathematically in an analysis of data by independent statisticians.
The analysis was conducted at the request of The Associated Press to investigate the legitimacy of talk of a cooling trend....

The statisticians, reviewing two sets of temperature data, found no trend of falling temperatures over time. ...

Statisticians say that in sizing up climate change, it's important to look at moving averages of about 10 years. They compare the average of 1999-2008 to the average of 2000-2009. In all data sets, 10-year moving averages have been higher in the last five years than in any previous years.
What gave this extra significance is that it was a type of blind analysis:
[T]he AP gave temperature data to four independent statisticians and asked them to look for trends, without telling them what the numbers represented.
The data was NOAA's year-to-year ground temperature changes over 130 years plus the 30 years of satellite-measured temperatures preferred by skeptics.
Statisticians who analyzed the data found a distinct decades-long upward trend in the numbers, but could not find a significant drop in the past 10 years in either data set. The ups and downs during the last decade repeat random variability in data as far back as 1880.
In short, the numbers say global cooling is a crock. Again, we knew that but it's always nice to have confirmation.

I found this part of the article bitterly amusing:
One prominent skeptic said that to find the cooling trend, the 30 years of satellite temperatures must be used. The satellite data tends to be cooler than the ground data. Key to that is making sure that 1998 is part of the trend, he added.

What happened within the past 10 years or so is what counts, not the overall average, contends Don Easterbrook, a Western Washington University geology professor and global warming skeptic.
In other words, to find this supposed "cooling trend," you have to use a specific set of data gathered over a specific period and then toss out most of that data and start at a specific year within that period. And ignore everything else.
"If you look at the data and sort of cherry-pick a microtrend within a bigger trend, that technique is particularly suspect," said John Grego, a professor of statistics at the University of South Carolina. ...

Grego produced three charts to show how choosing a starting date can alter perceptions. Using the skeptics' satellite data beginning in 1998, there is a "mild downward trend," he said. But doing that is "deceptive."

The trend disappears if the analysis is begun in 1997. And it trends upward if you begin in 1999, he said.
Cherry-picking of data is exactly what the nanny-nanny naysayers have been reduced to. And yet the media still treats them as if they were part of a legitimate dispute. Damn.

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