Ocean warming on the riseJune 19, 2008Increased scientific confidence that ocean observations are accurately reflecting rising global temperatures is central to new Australian research published today in the journal, Nature. The team of Australian and US climate researchers found the world's oceans warmed and rose at a rate 50 per cent faster in the last four decades of the 20th century than documented in the 2007 Intergovernmental Panel on Climate Change Report (IPCC AR4). The research gives significantly greater credibility to the way climate models simulate the degree of warming in the world's oceans - a key indicator of sea-level rise and climate change. The results were added to other recent estimates of contributions to sea-level rise, including glaciers, ice caps, Greenland and Antarctic ice sheets, and thermal expansion changes in the deep ocean. The sum of all contributions is more consistent with observed sea-level rise than earlier studies. "For the first time, we can provide a reasonable account of the processes causing the rate of global sea-level rise over the past four decades - a puzzle that has led to a lot of scientific discussion since the 2001 IPCC report but with no significant advances until now," says CSIRO Wealth from Oceans National Research Flagship scientist, Dr Catia Domingues, from the Centre for Australian Weather and Climate Research. "Following the review of millions of ocean measurements, predominantly from expendable instruments probing the upper 700 metres of the ocean, we were able to more accurately estimate upper-ocean warming, and the related thermal expansion and sea-level rise. "We show that the rate of ocean warming from 1961 to 2003 is about 50 per cent larger than previously reported," Dr Domingues says., The new estimates also more closely agree with the models used in the IPCC 2007 report. "Our results are important for the climate modelling community because they boost confidence in the climate models used for projections of global sea-level rise resulting from the accumulation of heat in the oceans. These projections will, in turn, assist in planning to minimise the impacts and in developing adaptation strategies." Central to unlocking more accurate estimates of upper-ocean warming and sea-level rise was research completed earlier this year by CSIRO's Dr Susan Wijffels and NASA's Dr Josh Willis, among others, and soon to be published in the American Meteorological Society's Journal of Climate. This study provided ways of correcting small but systematic biases recently discovered in 70 per cent of measurements in the global ocean observing system. Dr Wijffels says the results also indicate an ongoing need for careful quality control of observational data and continuous monitoring of the oceans using diverse observations that can be checked against each other. Dr Domingues says the oceans store more than 90 per cent of the heat in the Earth's climate system and act as a temporary buffer against the effects of climate change. "Detailed comparisons of these new observational estimates with climate models will be required to refine our current understanding and improve projections of the regional distribution of sea-level rise," she says. The science team included researchers from the Centre for Australian Weather and Climate Research, the Antarctic Climate and Ecosystem Cooperative Research Centre and the Lawrence Livermore National Laboratory, California USA. Co-authors were John Church, Neil White, Peter Gleckler; Susan Wijffels, Paul Barker and Jeff Dunn. CSIRO |
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| Related Global Temperatures Current Events and Global Temperatures News Articles Shifting the world to 100 percent clean, renewable energy as early as 2030 -- here are the numbers Most of the technology needed to shift the world from fossil fuel to clean, renewable energy already exists. Implementing that technology requires overcoming obstacles in planning and politics, but doing so could result in a 30 percent decrease in global power demand. As Greenland melts Not that long ago - the blink of a geologic eye - global temperatures were so warm that ice on Greenland could have been hard to come by. Today, the largest island in the world is covered with ice 1.6 miles thick. Even so, Greenland has become a hot spot for climate scientists. Last time carbon dioxide levels were this high: 15 million years ago, scientists report You would have to go back at least 15 million years to find carbon dioxide levels on Earth as high as they are today, a UCLA scientist and colleagues report Oct. 8 in the online edition of the journal Science. Climate change triggered dwarfism in soil-dwelling creatures of the past Ancient soil-inhabiting creatures decreased in body size by nearly half in response to a period of boosted carbon dioxide levels and higher temperatures, scientists have discovered. North meets south? Glaciers move together in far-flung regions Results of a new study add evidence that climate swings in the northern hemisphere over the past 12,000 years have been tightly linked to changes in the tropics. Hundreds of New Species Discovered in Fragile Eastern Himalayas Over 350 new species including the world's smallest deer, a "flying frog" and a 100 million-year old gecko have been discovered in the Eastern Himalayas, a biological treasure trove now threatened by climate change. World's largest aerosol sensing network has leafy origins Twenty years ago, Brent Holben was part of a NASA team studying vegetation from space. In an unlikely career twist, his research morphed into the study of a critical, if overlooked, subplot in the story of climate change. Global sunscreen won't save corals Emergency plans to counteract global warming by artificially shading the Earth from incoming sunlight might lower the planet's temperature a few degrees, but such "geoengineering" solutions would do little to stop the acidification of the world oceans that threatens coral reefs and other marine life. Reviving American chestnuts may mitigate climate change A Purdue University study shows that introducing a new hybrid of the American chestnut tree would not only bring back the all-but-extinct species, but also put a dent in the amount of carbon in the Earth's atmosphere. UBC researcher solves century-old enigma of prehistoric marine mass grave Good old-fashioned detective work has turned up the first conclusive explanation for the origin of a massive bonebed in southern California, according to a new study led by a UBC paleontologist. More Global Temperatures Current Events and Global Temperatures News Articles |
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