Global warming is reducing ocean life, increasing atmospheric carbon dioxide, say scientistsDecember 07, 2006(Santa Barbara, Calif.) -- Alarming new satellite data show that the warming of the world's oceans is reducing ocean life while contributing to increased global warming. The ocean's food chain is based upon the growth of billions upon billions of microscopic plants. New satellite data show that ocean warming is reducing these plants -- thus imperiling ocean fisheries and marine life, according to an article in the Nov. 7 issue of the scientific journal Nature. "We show on a global scale that the growth of these plants, called phytoplankton, is strongly tied to changes in the warming of the ocean," said David Siegel, co-author and professor of marine science in the Department of Geography at the University of California, Santa Barbara. Siegel is also director of the Institute for Computational Earth System Science (ICESS).
"Phytoplankton grow faster in a cool ocean and slower in a warm one," said Siegel. "The scary part is that the oceans are warming now -- probably caused by our emissions of greenhouse gases like carbon dioxide." These microscopic plants are predicted to grow even slower in the warmer oceans of the future. This in turn will reduce the food available to fish and other organisms, including marine birds and mammals, which are supported by the ocean's food chain. Phytoplankton are responsible for about the same amount of photosynthesis each year as all the plants on land combined. Another disturbing result of reduced phytoplankton is that our atmosphere depends on the consumption of atmospheric carbon dioxide by these plants. Reduced phytoplankton means less carbon dioxide is taken up by the ocean, which could speed global warming, contributing to a vicious cycle of increased warming. "Rising levels of carbon dioxide in the atmosphere play a big part in global warming," said lead author Michael Behrenfeld of Oregon State University. "This study shows that as the climate warms, phytoplankton growth rates go down and along with them the amount of carbon dioxide these ocean plants consume. That allows carbon dioxide to accumulate more rapidly in the atmosphere, which would produce more warming." The findings are from a NASA-funded analysis of data from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) instrument on the OrbView-2 spacecraft, launched in 1997. The uninterrupted nine-year record shows in great detail the ups and downs of marine biological activity or productivity from month to month and year to year. Captured at the start of this data record was a major, rapid rebound in ocean biological activity after a major El Niño event. El Niño and La Niña are major warming or cooling events, respectively, that occur approximately every three to seven years in the eastern Pacific Ocean and are known to change weather patterns around the world. Scientists made their discovery by comparing the SeaWiFS record of the rise and fall of global ocean plant life to different measures of recent global climate change. The climate records included several factors that directly affect ocean conditions, such as changes in sea surface temperature and surface winds. The results support computer model predictions of what could happen to the world's oceans as the result of prolonged future climate warming. "When we compared changes in phytoplankton activity with simultaneous changes in climate conditions, the agreement between the two records was simply astonishing," Behrenfeld said. Ocean plant growth increased from 1997 to 1999 as the climate cooled during one of the strongest El Niño to La Niña transitions on record. Since 1999, the climate has been in a period of warming that has seen the health of ocean plants diminish. The new study also explains why a change in climate produces this effect on ocean plant life. When the climate warms, the temperature of the upper ocean also increases, making it "lighter" than the denser cold water beneath it. This results in a layering or "stratification" of ocean waters that creates an effective barrier between the surface layer and the nutrients below, cutting off phytoplankton's food supply. The scientists confirmed this effect by comparing records of ocean surface water density with the SeaWiFS biological data. University of California - Santa Barbara | |||||||||||||||||||||
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Related Global Warming Current Events and Global Warming News Articles Warming in Yosemite National Park sends small mammals packing to higher, cooler elevations Global warming is causing major shifts in the range of small mammals in Yosemite National Park, one of the nation's treasures that was set aside as a public trust 144 years ago, according to a new study by University of California, Berkeley, biologists. Smithsonian perspective: Biodiversity in a warmer world Will climate change exceed life's ability to respond? Biodiversity in a Warmer World, published in the Oct. 10, 2008 issue of the journal, Science, illustrates that cross-disciplinary research fostered by the Smithsonian Tropical Research Institute in Panama clearly informs this urgent debate. Future Risk of Hurricanes: The Role of Climate Change Researchers are homing in on the hurricane-prone Gulf of Mexico and Caribbean Sea to assess the likely changes, between now and the middle of the century, in the frequency, intensity, and tracks of these powerful storms. Initial results are expected early next year. Waterborne disease risk upped in Great Lakes An anticipated increased incidence of climate-related extreme rainfall events in the Great Lakes region may raise the public health risk for the 40 million people who depend on the lakes for their drinking water, according to a new study. Brookhaven Scientists Take Off for Southeastern Pacific Climate Study During October and November 2008, some 150 scientists from 40 institutions in eight nations - including scientists from the U.S. Department of Energy's (DOE) Brookhaven National Laboratory - will take part in an international field experiment designed to make observations of critical components of the climate system of the southeastern Pacific. NASA study finds rising Arctic storm activity sways sea ice, climate A new NASA study shows that the rising frequency and intensity of arctic storms over the last half century, attributed to progressively warmer waters, directly provoked acceleration of the rate of arctic sea ice drift, long considered by scientists as a bellwether of climate change. Gas from the past gives scientists new insights into climate and the oceans In recent years, public discussion of climate change has included concerns that increased levels of carbon dioxide will contribute to global warming, which in turn may change the circulation in the earth's oceans, with potentially disastrous consequences. Researchers document world's mammals in crisis From majestic African elephants to tiny and often unappreciated rodents, mammals on Earth are in a state of crisis. One in four mammal species on Earth is being pushed to extinction, according to the Global Mammal Assessment, the most comprehensive assessment of the world's mammals. Are we trading energy conservation for toxic air emissions? A team of Yale scientists has found that certain countries and some U.S. states stand to benefit from the use of compact fluorescent lighting more than others in the fight against global warming. Some places may even produce more mercury emissions by switching from incandescent light bulbs to compact fluorescent lighting. Scientist proposes explanation for puzzling property of night-shining clouds at the edge of space An explanation for a strange property of noctilucent clouds--thin, wispy clouds hovering at the edge of space at 85 km altitude--has been proposed by an experimental plasma physicist at the California Institute of Technology (Caltech), possibly laying to rest a decades-long mystery. More Global Warming Current Events and Global Warming News Articles |
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