Climate Change Facts - Ocean Impacts

  • Oceans are acidifying 10 times faster now than 55 million years ago when a mass extinction of marine species occurred. (University of Bristol researchers, in Nature Geoscience, 2010)
  • If emissions aren’t stopped, a mass marine extinction is possible by the end of the century with degraded coastal waters and outbreaks of toxic algae and jellyfish. (Geological Society of London, 2010)


  • Oxygen-depleted dead zones caused by global warming can remain for thousands of years. (Shaffer et al. in Nature Geoscience, 2009) Climate change, as well as agricultural run-off, is causing new and larger low-oxygen dead zones. Now well over 400 in number and usually along coasts, dead zones have been doubling every decade since the 1960s. (Science, 2008)
  • Toxic algae growth could become a tipping point. In the Baltic Sea, record high temperatures in summer 2010 led to an immense patch of algae the size of Germany, and spreading.  Toxic algae infestations are occurring with ever greater frequency in both inland and ocean waters worldwide.


  • In Southeast Asia and the Indian Ocean, experts are reporting coral bleaching in 2010 as the worst since 1998, when a similar event caused 16% of the world’s coral reefs to perish. (Australian Research Council (ARC) Centre of Excellence for Coral Reef Studies)


  • Over the next century, the Atlantic Ocean circulation might slow to a stop or reverse due to large amounts of melted freshwater changing the ocean’s salt concentration. Such an event could trigger an Ice Age in Europe and North America.  (Woods Hole Oceanographic Institution, 2003)


  • An estimated 90% of the heat from greenhouse gases over the past 50 years has been absorbed by the oceans, all the way to the deep ocean floor. If the heat currently being poured into the deep ocean were to stay in the atmosphere instead, our ambient temperature would rise at a rate of 3 degrees Celsius per decade. The Antarctic Ocean has the strongest deep warming, and is adding to sea level rise as well, both through expansion and the melt of land ice into the ocean. (Sarah Purkey, an oceanographer at the University of Washington, USA)
  • Frozen methane from beneath the ocean floor could be released in massive amounts if the oceans are warmed enough, thus leading to further catastrophic warming. Sudden explosive releases of methane could also trigger 15-meter tsunamis. At the current rate, sea temperatures could increase by as much as 5.8 degrees Celsius by 2100. (The Royal Geographical Society. Dr. Mark Maslin, Senior Reader in Geography at University College London and a senior researcher for the London Environmental Change Research Centre, 2005)
  • The ocean temperature is rising 50% faster than previous 2007 estimates.


  • Warming oceans caused a 40% decline in phytoplankton populations since 1950, which will have serious consequences. Phytoplankton not only provides crucial support to the marine ecosystem, it produces half the world’s oxygen, and eliminates CO2. (Boyce et al. Nature, Jul 2010)


  • Dr. John Holdren, president of American Association for the Advancement of Science, predicts a possible 4-meter sea level rise by end of the century, and Dr. James Hansen, NASA’s head of Goddard Institute for Space Studies, has stated the likelihood of a 5-meter sea level rise by end of the century. (2006, 2007, respectively.)
  • A sea level rise of even 1 meter would result in over 100 million climate refugees and endanger major cities like London, Cairo, Bangkok, Venice, New York, and Shanghai.
  • Examples of countries affected by sea level rise:
    • Âu Lạc (Vietnam). At the nation’s rice bowl region, the Mekong Delta, ocean salt water has encroached an unprecedented 60 kilometers up-river in 2010, threatening 100,000 hectares of rice.
    • Thailand. Seawater is expected to reach Bangkok’s ground level in 25 years. (GEodetic Earth Observation Technologies for Thailand: Environmental Change Detection and Investigation, 2010)
    • Egypt. More than 58 meters of coastline have vanished every year since 1989 in Rasheed. (Omran Frihy of the Coastal Research Institute, 2010)
  • Sea level rise caused at least 18 island nations to completely disappear while many more coastal areas are continually threatened. More than 40 other island nations are at risk from rising sea levels.
  • Sea level rise threatens half of the world's population living within 200 kilometers of a coastline. Already, low-lying coastal regions and deltas see effects: 17 million in Bangladesh have fled their homes, mainly because of coastal erosion. Groundwater sources are contaminated by saltwater in Israel and Thailand, small island states in the Pacific and Indian Oceans and the Caribbean Sea, and in some of the world's major deltas, such as the Yangtze Delta and Mekong Delta.

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