Climate scientists have long predicted that global warming will melt polar ice sheets and cause sea levels to rise throughout the century, potentially swamping island nations and flooding low-lying coastal cities. But exactly how much ocean waters will rise has yet to be settled. Now, two studies have come out that at first appear to contradict each other, leading to clashing headlines like “An Inconvenient Truth” Exaggerated Sea Level Rise [Telegraph], and Sea Level Rise May Be Twice More Than Expected [Discovery News].
One study seems to downplay the risk of an extreme sea-level rise, while the other hypes it up. But a closer look reveals that the two studies actually bring researchers nearer to scientific consensus.
In the study published in Science [subscription required], researchers examined the hypothesis of a six-foot sea-level rise by 2100, and calculated how quickly the ice sheets in Greenland and Antarctica would have to melt into the oceans to produce this effect. Their calculations showed that the glaciers would have to essentially gallop towards the sea, which seems an unlikely outcome. In Greenland, the glaciers moving into the island’s calving fjords would have to increase their speed to 28.4 miles per year and sustain that speed until the end of the century [Telegraph]. These researchers believe the most plausible scenario is a sea-level rise of between two and six feet within this century. As their results have been compared to more radical estimates like the 20-foot rise mentioned in the documentary film An Inconvenient Truth, the findings are being greeted with relief.
Meanwhile, a paper published in Nature Geoscience [subscription required] ultimately came to a similar estimate, but was presented very differently. Researchers looked at what had happened at the end of the last ice age, when the last fragments of the Laurentide ice sheet covered much of north-eastern Canada [New Scientist]. They studied the geological record and used computer simulations to determine how long it took the Laurentide ice sheet to melt away completely and how much it raised sea levels, and determined that the event raised ocean levels about three feet per century.
These researchers say that atmospheric conditions at the end of the last ice age are similar to what the world will experience before 2100, and say the vast Greenland ice sheet could begin to melt more rapidly than expected towards the end of the century, accelerating the rise in sea levels [Guardian]. But while the three-foot rise this model predicts is in line with the other study’s estimate, it has gotten a different reception. Because it was compared to the UN’s Intergovernmental Panel on Climate Change official estimate of a seven-inch to two-foot rise by 2100, this second study has been presented as an alarm bell.
The take-home point is that both research groups say the world is likely to see oceans rise by at least two feet before the end of the century, which would still cause trouble for coastal nations like Bangladesh and the Netherlands, and could bring more damaging floods to U.S. cities like New York and New Orleans. Says Tad Pfeffer, one study’s author: Just because the amount of sea-level rise predicted in the new study is “not a Hollywood cataclysm, it doesn’t mean it’s not important” [National Geographic News].
Image: flickr/Stig Nygaard
September 6th, 2008 at 2:29 am
Any honest climatologist will admit that nobody on Earth, living or dead, can possibly predict the climate more than a few years in advance. All this fret, panic, debate, and (unfortunately) flat-out shameless lying gets us nowhere.
Al Gore was famous in the U.S. as a pathalogical liar, on many different topics, for years before he grabbed onto this global warming thing.
September 6th, 2008 at 3:16 am
If the Earth is cooling, why would the ice caps melt? If they’re melting now, why are they getting bigger? How do they melt if the temperature stays well below freezing?
September 6th, 2008 at 10:30 pm
There’s no ignorance like willful ignorance.
September 7th, 2008 at 2:19 am
@Juggernaut
The ice packs in the arctic haven’t increased they’ve shrunk, but the over all snow fall has increased. Both of these facts have predicted by global warming models for over thirty years.
Despite being full of ice and snow, the arctic is essentially a desert. As normally there is little moisture in the air, the average yearly snow fall is only 2 inches per year, but as the snow packs have melted, the humidity has risen and along with it increased overall snow fall across the region. Unfortunately not remotely enough to replace the ice and snow that is being lost due to the melt.
The reason the ice melts in the arctic is because, most of it sits on top of ocean, and while the air temperature rarely rises high enough to melt ice, the water temperature does.
If you have any more questions feel free to ask, but otherwise feel free to investigate for yourself.
Your sitting in front of the single most powerful information gathering tool ever invented, and to use it to spread denier talking points rather then actually look for facts seems like a waste of effort.
October 18th, 2009 at 12:33 pm
Quote: Netwatcher
“Your sitting in front of the single most powerful information gathering tool ever invented, and to use it to spread denier talking points rather then actually look for facts seems like a waste of effort.”
Right! We now have an eye on the world (of knowledge) unparalleled in Human history.
Sitting there without doing research is a waste of everybody’s time. Others can do better with their time than the need to answer biased or uneducated questions to prevent the start of “undesirable believes” roaming around.
The internet connected PC together with Television in particular educational channels like Animal Planet, National Geographic and Discovery Channel give us opportunities for “Quantum Leaping” gains in personal and collective knowledge , unprecedented for in Human existence.
So go out and venture for yourself, use your knowledge in preservation of Earth, nature and all that lives upon and in it.
Truth consists solely out of two components:
1. Ethicality
and
2. Responsibility
Keep that in mind in all of your decisions.
Kind regards,
Dan Bekkering.
http://www.BioEthicUS.org
http://www.AmnestyForAnimals.org
http://www.BuyOnIcle.com