Oceans Absorbing Less CO2 May Have 1,500 Year Impact

Global oceans are soaking up less carbon dioxide, a developmentthat could speed up the greenhouse effect and have an impact for thenext 1,500 years, scientists said on Wednesday. Research from a five-year project funded by the European Union showedthe North Atlantic, which along with the Antarctic is of the world's twovital ocean carbon sinks, is absorbing only half the amount of CO2 thatit did in the mid-1990s. Using recent detailed data, scientists said the amount absorbed is alsofluctuating each year, making it hard to predict how and whether thetrend will continue and if oceans will be able to perform their vitalbalancing act in the future. Oceans soak up around a quarter of annual CO2 emissions, but should theyfail to do so in the future the gas would stay in the atmosphere andcould accelerate the greenhouse effect, a prospect project directorChristoph Heinze called "alarming". Oceans are like a "slow-mixing machine". Carbon absorbed in the NorthAtlantic takes around 1,500 years to circulate around the world's seas.This means changes to their fragile balance could be felt long into thefuture, Heinze said at a geoscience conference in Vienna. Scientists are still debating the reasons why oceans are absorbing lesscarbon dioxide. While some point to CO2 saturation, others say it couldbe caused by a change in surface water circulation, triggered by changesin weather cycles. Heinze described a "bottleneck effect" because of the large amount ofmanmade carbon dioxide oceans already store. "The more CO2 the oceans store, the more difficult it will be for themto take up the additional load from the atmosphere and carbon absorptionwill stagnate even further," Heinze said. Some forms of sea life have suffered from the large amounts of CO2absorbed, because of changes in acidity levels. "The seafloor is becoming an increasingly hostile environment," saidMarion Gehlen, from the Laboratory of Climate and Environment Science inFrance. "This corrosive water means mollusc organisms have a hard time makingtheir shells and eventually they might not be able to do it at all." For the scientists there is only one thing humans can do to resolve theproblem -- reduce emissions by at least 75 percent. "We must act now. The good news is that while the negative effects canlast a long time, the good things we do will also have an effect for thenext 1,500 years," Heinze said. "It's cheap and it's possible to do this but people must have the willto do it." Story by Sylvia Westall Story Date: 17/4/2008