Friday, October 26, 2012

NASA's latest polar sea ice images, north and south

Sea ice September 2012. Arctic summer, Antarctic winter. Yellow outlines indicate previous averages.
Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio and NASA Earth Observatory/ Jesse Allen
NASA doesn't only explore the solar system, it has an Earth monitoring programme and employs climate scientists. A few days ago they issued two striking images of Arctic and Antarctic sea ice.  Enlarged images available on NASA Earth page.

September 2012 witnessed two opposite records.

Left: the Arctic Ocean's ice cap experienced an all-time summertime low for the satellite era.

Right: Two weeks later, Antarctic sea ice reached a record winter maximum. (In extent, though not thickness.) 

The yellow outlines are for comparison, indicating recent averages. In the Arctic image, average sea ice minimum extent from 1979 to 2010. In the Antarctic image, median sea ice extent in September from 1979 to 2000.

Dr James E. Hansen
NASA says that sea ice in the Arctic has melted at a much faster rate than it has expanded in the Southern Ocean, as can be seen in this image by comparing the 2012 sea ice levels with the yellow outline.

Dr Claire Parkinson, a climate scientist with NASA's Goddard Space Flight Center is quoted saying : "There's been an overall increase in the sea ice cover in the Antarctic, which is the opposite of what is happening in the Arctic. However, this growth rate is not nearly as large as the decrease in the Arctic.”

Lest we take the Antarctic image as a hopeful sign, she cautions that
some areas of the Southern Ocean cooling and producing more sea ice does not disprove a warming climate.

"Climate does not change uniformly: The Earth is very large and the expectation definitely would be that there would be different changes in different regions of the world.  That's true even if overall the system is warming.”

Another recent NASA study showed that Antarctic sea ice slightly thinned from 2003 to 2008, but increases in the extent of the ice balanced the loss in thickness and led to an overall volume gain.

NASA's Goddard Institute for Space Studies is led by James Hansen, a noted climatologist who has become a hate figure for oil companies due to his warnings about human-induced climate change.  

Wednesday, October 24, 2012

6 years for seismologists? What about economists?

The earthquake in L'Aquila destroyed the city and
killed more than 300 people in 2009. (Irish Times)
Let’s talk about the six Italian seismologists and a civil servant who this week face 6 years jail for failing to give adequate warning of a deadly earthquake. 

Best tweet so far is from Ursula ‏@UrsulaWJ :

what, seriously, they've sentenced scientists to jail for failing to predict an earthquake? I'm off to round up the economists.

Yet defence of the convictions - if not the sentences - is coming in from surprising quarters. (For a catch-up on the story so far, see foot of this post.)

New Scientist says that whilst it's easy to feel outrage at the jail terms - how could anyone hope to have predicted the earthquake? – the fact is that failure to predict is not what the seven men have been convicted of. The prosecution case was about poor risk communication; it was built on an accusation of giving out "inexact, incomplete and contradictory information".

Likewise Stuart Clark in a Guardian blog asks: was this trial about science or communication? Whilst the media is filled with stories about science being on trial, claiming that the scientists have been convicted of failing to predict the earthquake, he says the conviction was actually for errors in communication.

Still and all, I think we ought to contribute to the defence fund, which I haven't seen notice of yet, but I'm sure we shall very soon.

I'm not a seismologist but I think it's a fair bet that “inexact, incomplete and contradictory” would pretty well describe the state of that science. The lesson: they ought to have issued a statement saying WE CAN’T PREDICT EARTHQUAKES, submitted their expenses claims, and gone home.

Italian science on trial again?

Stuart Clark draws a parallel with the Galileo trial and says that, too, has been misinterpreted: the Vatican wasn’t against astronomy, just about the way Galileo communicated it.  Galileo was arraigned for communicating too much, the seismologists for too little.

To digress, Stuart illustrates his blog with the famous picture by Cristiano Banti  "Galileo facing the Roman Inquisition" (1857):

This is 19th century romanticisation, I fear. Galileo’s demeanour at his trial was very far from the defiance depicted here. More like grovelling actually.

The story so far

The controversial earthquake sentence was handed down Monday by an Italian court sitting in L’Aquila, the city destroyed on April 6th, 2009, with more than 1,000 people injured, and hundreds of others killed in their sleep.

The seven, all members of an official body called the National Commission for the Forecast and Prevention of Major Risks, were accused of negligence and malpractice in their evaluation of the danger of an earthquake and their duty to keep the city informed of the risks.

The case has drawn wide condemnation from international bodies including the American Geophysical Union, which said the risk of litigation may deter scientists from advising governments or even working to assess seismic risk.

According to today's Irish Times, the speaker of the Italian senate, Renato Schifani, commented: “This is a strange and embarrassing sentence. In future, [experts] asked to serve on committees like this will simply refuse.”

And one of those sentenced, Prof Enzo Boschi, said he was “desperate”, claiming he had been expecting to be acquitted. “I don’t even understand what I have been accused of, I never issued any reassurance to anyone, not I. All I said was that earthquakes are unpredictable .... I would never have excluded the possibility of a major quake in the Abruzzo, I’d have to be mad to do that.”

At the heart of the case (says Reuters) was whether the government-appointed experts gave an overly reassuring picture of the risks facing the town, which contained many ancient and fragile buildings and which had been partially destroyed three times by earthquakes over the centuries.

The case focused in particular on a series of low-level tremors which hit the region in the months preceding the earthquake and which prosecutors said should have warned experts not to underestimate the risk of a major shock.