Environment Forum
Global environmental challenges
Voyage around the Americas sees acidification off Alaska
Scientists aboard the Ocean Watch, a 64-foot yacht on a year-long voyage circling the Americas, are testing the waters as they go. Instruments on the vessel have picked up evidence of ocean acidification, another result of the spewing of carbon dioxide from tailpipes and smokestacks, they say. Much of CO2 pollution ends up in the atmosphere, but some is absorbed in the ocean, where it is converted into carbonic acid. The average pH of the word’s oceans is about 8.1 and the lower the reading, the greater the acidity. Scientists are concerned that if pH levels keep falling ocean waters could eat away the shells of organisms large and small. That would put the web of ocean life at risk, not to mention be a potential disaster for land-loving seafood lovers Ocean Watch has picked up readings of 7.88 in the Gulf of Alaska. Michael Reynolds, the scientist taking the measurements, said the preliminary data may show that the Gulf of Alaska is a primary “sink” for atmospheric carbon. The good news is that readings have returned to normal as the voyage continues off the coast of South America.
The Ocean Watch has taken other environmental observations, on things like declining ice cover in the Arctic, and it sailed through the Northwest Passage, one of only 100 ships to do so in the last 100 years. A special camera is observing the gaggles of jellyfish the ship encounters. The creatures are among the world’s hardiest, so the scientists want to see what kind of jellyfish are thriving in waters that are acidic or are polluted in other ways and what changes they are undergoing. “The boat is acting as a spotlight on issues known to scientists and local fisherman, but are not known to the general public,” said David Rockefeller, a philanthropist who is sponsoring the $2 million voyage for Sailors for the Sea. He will climb aboard Ocean Watch later this month off the coast of Patagonia. The sailors are sharing their observations and concerns with the public at ports along their journey. Ellen Lettvin, an education expert at the Pacific Science Center, said the Ocean Watch scientists will analyze the data at the end of the voyage and provide it to the National Oceanic and Atmospheric Administration and other organizations tracking the health of the oceans.
Photo: David Thoreson
Seas rise — vast amounts of ice melt for every 1 mm gain
It takes the equivalent of a massive chunk of ice of 390 cubic kms (150 cubic miles) to raise world sea levels by one millimetre, according to David Carlson, director of the International Programme Office of the International Polar Year.
As an example, he says that works out as a lump 39 kms long, 10 wide and 1 km thick. Or I reckon it could be a blockbuster ice cube with sides 7.3 kms long — that would smother most of a large city such as Paris (top left — you can see the Eiffel Tower in the middle).
David’s numbers give an idea of the scale of the thaw under way — seas have been rising at about 3 millimetres a year in recent years in a trend that almost all climate scientists blame on global warming caused by human activities. That’s equivalent to a rate of 30 cms a century.
And it’s also a lot faster than a rise of 1.8 mm a year from the 1960s, according to the U.N. Climate Panel. The thaw is one of the spurs to action under plans for a new U.N. treaty to fight global warming due to be agreed in Copenhagen in December.
Some scientists reckon seas could rise by one metre this century. Most of the rise projected by 2100, however, is likely because water expands as it gets warmer, rather than because of a thaw of glaciers or of ice sheets smothering Greenland or Antarctica.
One bit of good news on the ice front is that it looks as if sea ice in the Arctic will not shrink to a new record low this summer, after 2007 marked the smallest since satellite records began in the 1970s (and probably a lot longer than that).
Ice shrinks to its annual low in September before freezing out again: so far the ice is still far bigger than in 2007 at the same time although it is also far smaller than the 1979-2000 average, according to the U.S. National Snow and Ice Data Center. And ice floating on the sea doesn’t really contribute to raising sea levels — it’s effectively part of the water already.
Why do you continue to refer to the term “Global Warming” when NASA and several CREDIBLE scientists have proven the earth has cooled each of at least the last nine years? This is irresponsible journalism at best and outright bias in reporting at worst. Mother Earth worshipers have changed the term to “Climate Change” because they can no longer call it “Global Warming”. But isn’t that just another word for “weather”? Oh, how the politically correct have taken over. Also, it is VERY clear science that even grade schoolers know, that melting ice does not increase water levels. Do the simple science experiment yourself with a glass or bowl of water and some ice cubes. Also, where is the mention that the ice in antartica is actually INCREASING? The only things the scientists have to “predict” the future are overly complex computer models. Who says these models are right? Them? Who funds them? The government? Al Gore? The end result is that those same models FAILED to predict the Global COOLING that has happened in the past few years. That tells me the models and flawed and therefore, the whole argument is questionable. 90% of the scientists? NO! This also is a misstatement and no fact.
A view from the North – Alaska’s melting glaciers
Welcome to the front lines of global warming in the United States – the Harding Ice Field in Alaska, the biggest icefield in the United States. At the Exit Glacier north of Seward – the only glacier in the Kenai Fjords National Park reachable by foot – the giant cerulean blue ice sheet gives every sign of staying put. But one only has to glance at the many signs along the roadway and footpath to the glacier’s edge to mark its retreat – it hit its peak size in 1815 and has been receding ever since. Signs along a footpath leading to the base of the glacier show just how far it has retreated. The glacier lost about 10 feet from its front face over the summer of 2008. Since the 1980s, land-based glaciers and ice caps like this one in Alaska have contributed the most to sea level rise than any other source within their category, which includes other land-based glaciers like Tanzania’s Mount Kilimanjaro and the Chacaltaya Glacier near La Paz, Bolivia, said Brenda Ekwurzel, a climate expert with the Union of Concerned Scientists. Unlike the ice cover around the North Pole or giant floating ice sheets, land-based ice contributes directly to sea-level rises. According to a 2007 report by the U.N.’s Intergovernmental Panel on Climate Change, glaciers and ice caps have the potential to raise global sea levels by between .15 meters and .37 meters. That pales in comparison to the giant ice sheets in Greenland and Antarctica, which could raise sea levels by 63.9 meters if they fully melted. At the Aialik Glacier in the Harding Icefield – reachable by boat or plane, the living nature of the ice was more evident. On a visit to the glacier via tourboat on Aug. 15 on a trip hosted by the Knight Center for Environmental Journalism, several chunks of ice broke apart and crashed into Aialik Bay. Throughout the visit, the ice cracked andgroaned, with a sound like thunder claps that punctuated the still air.
Is the melting glaciers of alaska a sign of things to come? I’m 17 and it’s sad when you think about what they used to be. I want to be a wildlife veterinarian and travel to Alaska. It sucks because my generation is far too late.
