As the months go past we are getting a clearer picture of just how fragile our environment really is. Many people like to blame every abnormal environmental occurrence on climate change and global warming. However a pattern that seems to be emerging is that global warming was simply the last straw.
I’ve personally reported several times over the past few months focusing on environmental issues that are not entirely man-made. Early in January I looked at a recent study in the journal Nature that indicated that a natural and cyclical increase in the amount of atmospheric energy was part of the cause the Arctic sea-ice so drastically failed to appear.
Three days later I introduced us to recent findings that indicated that the warming of the North Atlantic was also not entirely the result of man-made global warming, but rather a natural and cyclical wind circulation pattern called the North Atlantic Oscillation.
I focus on these now to once again put forth the idea in your minds that Green Options is not about blaming everything on mankind.
But this next study once again helps me to reiterate that while we are not the sole contributor to the problems, we have tipped the balance.
Back between January and March of 2002 we watched as Antarctica’s 3200-square kilometer Larsen B ice shelf broke apart. Many of the scientists blamed this abrupt breakup on climate change, including the previous warm summers and melt ponds – ponds of melted ice that form beneath the ice shelf, helping the shelf slide and break apart – rather than looking for more answers.
“But the picture is much more complicated,” says Neil Glasser of Aberystwyth University in the UK who, along with Ted Scambos of the University of Colorado at Boulder, has been tracking increased movement of glaciers near where Larsen B used to be.
When the pair reviewed satellite imagery from 1987 onwards, what they saw added another catalyst to the eventual breakup of Larsen B. Giant rifts and crevasses were formed as a result of long-term glaciological processes. And while these alone could not have caused the break up, they didn’t help. Glasser and Scambos believe that once global warming came in to play, thinning the ice, the glaciological stress was too much.
“Had it not got warmer, the shelf would have survived,” says Glasser. “It’s very likely that the warm summers could have been the final trigger.”
Following on with their research, the pair are now turning their attention to the 15,000 square-kilometer Larsen C ice shelf. As Larsen B once did, Larsen C slows the flow in to the sea of nearby glaciers by acting as a giant stopper. If it broke up, the resulting plunge of glaciers in to the ocean could have “a noticeable effect” on sea level, says Glasser.
Photo Courtesy of Pathfinder Linden via Flickr
New Scientist – Natural rifts may have weakened Antarctic ice shelf