Problems: Climate change

Coral reefs: the first major casualty of climate change?

The world's ten warmest years since 1856 have occurred in the last two decades - affecting marine habitats and species around the world.

Human activities, such as burning fossil fuels for energy, have released vast amounts of carbon dioxide (CO₂) and other greenhouse gases into the Earth's atmosphere. This is causing global warming and climate change - which in turn are profoundly altering our planet.

The oceans are not exempt. The current increase in global temperature of 0.7°C since pre-industrial times is already disrupting life in the oceans, from the tropics to the poles. The species affected include everything from plankton, which forms the basis of marine food chains, to corals, fish, polar bears, walruses, seals, sea lions, penguins, and seabirds.

The Intergovernmental Panel on Climate Change (IPCC) predicts a further rise of between 1.4°C and 5.8°C by the end of the century. Global warming could therefore well be the knock-out punch for many species which are already under stress from overfishing and habitat loss.

Wide range of impacts
The IPCC and other scientific studies predict several large-scale impacts of climate change on oceans. These include:

• increases in sea surface temperature, leading to increased coral bleaching, changing habitats, changing biology, and increased disease
• increased impacts of storms on coastal areas
• decreases in sea-ice cover and changes in salinity, wave conditions, and ocean circulation, leading to changing habitats
• sea level rise
• ocean water becoming acidic
  

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