Guest post by Thomas Fuller
It is hard to understand many of those who are convinced that climate change will destroy civilization. Previous ideas about massive sea level rise or tipping points leading to unending temperature increases have been debunked. Conventional theory on climate change points to moderate temperature and sea level rises that can be dealt with using existing technology, although the sooner we start the easier it will be.
But for some, the need to believe (and to preach) about a coming catastrophe is so strong that they are willing to overturn their own theories to take temporary advantage of ephemeral observations that will support their apocalyptic vision of the future.
The Gravity Recovery and Climate Experiment has been an operational satellite mission since 2002, measuring differences in the Earth’s gravity. Pictures of our planet using GRACE look more like a partially deflated soccer ball than the pristine globe we’re more accustomed to seeing.
As written in Wikipedia:
“GRACE is the first Earth-monitoring mission in the history of space flight whose key measurement is not derived from electromagnetic waves either reflected off, emitted by, or transmitted through Earth’s surface and/or atmosphere. Instead, the mission uses a microwave ranging system to accurately measure changes in the speed and distance between two identical spacecraft flying in a polar orbit about 220 kilometers (137 miles) apart, 500 kilometers (311 miles) above Earth. The ranging system is so sensitive it can detect separation changes as small as 10 microns—about one-tenth the width of a human hair over a distance of 220 kilometers.”
And according to some scientists working with GRACE measurements, Antarctica is losing ice. Not just the Western Antarctic Ice Sheet, which has been predicted to melt and succumb to mechanical pressure since the 1930s, but also the vastly larger ice sheet covering East Antarctica.
And sure enough, the ‘apocaholics’ are all over this, using it to reinforce their unrelenting drumbeat of doom-laden predictions of disastrous sea level rises.
But this is actually quite strange. According to climate change theory, ice should be increasing in Antarctica–the (very slight) increase in temperatures and the natural increase in precipitation should result in more snow over Antarctica which gets compressed into higher levels of ice. The same phenomenon is both predicted and observed in Greenland, by the way.
Instead of using this as proof of global warming, these people should be either wondering about the measurements or re-examining their theories. Because this is observed data working against the principles of their theory… But they cannot pass up the chance for a quick and easy headline that reinforces the ‘all disaster, only disaster, 24 hours a day’ routine.
Certainly all measurements before GRACE showed increasing ice in Antarctica, as they do today.
My guess (I’m not a scientist and do not claim to know) is that there are still a few bugs to work out in how they are doing this. If you recall, when satellites first started being used to measure Earth temperatures, there were a few glitches caused by orbital decay and other mechanical problems.
Certainly their description of how they analyze the data provided by GRACE shows many an opportunity for error to creep in. They use a bit of guess work and inferences from computer models to create base levels for the land that rises and falls under the differing levels of ice. Which is what they have to do at the moment, until they get enough real base data. I’m certainly not blaming the scientists for any of this. They’re proceeding the way they have to proceed. My beef is with those who step in front of the scientists with their interpretations.
So the paper referred to by scare artists like Michael Tobis of Only In It For The Gold says the Eastern Antarctic has lost 57 billion tons a year–plus or minus 52 billion tons. Hmm. I think we need a few more orbits, myself. Having a margin of error as large as the original figure doesn’t inspire confidence.
But to hear some talk, it’s back to the Day After Tomorrow tidal waves drowning New York. You can always tell when they’re trying to scare you–they talk about firm figures for how much ice is melting, without the data needed to put it into perspective. 57 billion tons certainly sounds like a lot of ice. However, as a percentage of the total it is not even an asterisk. Antarctica has 150 million billion tons of ice…
Do you remember that iceberg that calved off Antarctica in March? (Calving is a perfectly normal event, and has nothing to do with climate change.) The one the size of Rhode Island? It was estimated at 860 billion tons.
“A 2008 study estimated that Antarctica loses about 1.6 trillion metric tons of ice each year, but gets nearly that much back as annual snowfall. The icy continent may suffer a net ice loss of about 100-200 billion metric tons per year, but Scambos said the exact figure remains uncertain.” (Live Science, Is Antarctica Falling Apart? March, 2010).
In essence, what we have here is a new satellite using new tools to take measurements. The data recovered is analyzed using guesses and inferences. Their analysis is presented with a margin of error as large as the amount of ice they say is melting from Antarctica. The loss is is less than 1% of the normal annual melt.
Other measurements, consistent with climate theory, have consistently shown the Antarctic gaining, not losing ice.
So obviously we’re all going to drown, right? Well, when I tried to have a discussion with Michael Tobis in the comments section of his weblog, it didn’t go too well. I’ll let one of his allies offer the final word from those trying to scare us all:
“Tom Fuller seems to have missed the point I made yesterday.
Sea levels are going to go way, way, way, way, way up.
Got it now?”
Umm, no. I don’t
Thomas Fuller http://www.redbubble.com/people/hfuller
Addendum by Anthony:
Meanwhile, GRACE data is coming under question, and a new technique yields different results:
The melting of the ice sheets of Greenland and West Antarctica is about twice as slow as previously thought. The study, conducted by TU Delft, SRON and the Jet Propulsion Laboratory. The scientists published their findings in the September issue of Nature Geoscience.
We have concluded that the Greenland and West Antarctica ice caps are melting at approximately half the speed originally predicted.’ The average rise in sea levels as a result of the melting ice caps is also lower.
Source below, click on image for original story. Interestingly, the NASA JPL website does not have this announcement on the Global Climate Change section or any other portion of the website that I can find.
WUWT has covered the GRACE issue previously: