Ocean Acidification Facts

  • One third of all carbon dioxide emitted by human activity has been absorbed by the world’s oceans, making our oceans more acidic than they have been for tens of millions of years.
  • Over the last 250 years, oceans have absorbed 530 billion tons of CO2, triggering a 30 percent increase in ocean acidity.
  • This excess CO2 is changing the chemistry of the sea and proving harmful for many forms of marine life; this process is known as Ocean Acidification.
  • Ocean Acidification could destroy all coral reefs by as early as 2050, disrupt other marine ecosystems and wipe out entire oceanic food chains.
  • Millions of marine species depend on coral reefs to feed, reproduce, and take refuge from predators. If coral reefs disappear, it will threaten the very survival of many reef dependent species and could trigger a Great Mass Extinction.
  • Scientific evidence suggests that four of the five Great Mass Extinctions have been associated with rapidly acidifying oceans – due to increase in the concentration of atmospheric CO2.
  • One of the greatest impacts that Ocean Acidification is having is on reef building corals, which are known as a ‘framework species’. Ocean Acidification is already slowing their growth rates which could lower the resiliency of corals and lead to their erosion and eventual extinction.
  • Delicate corals also face the greatest risk because they require very high levels of carbonate to build their skeletons. Without corals, reefs simply cannot exist.
  • Before humans started burning coal and oil, ocean pH levels had been relatively stable for 20 million years. Research indicates that if carbon emissions continue at their current rate, ocean acidity will more than double by 2100.
  • Ocean plankton provide 50% of the oxygen that we breathe. Due to Global Warming, that capacity to provide oxygen and support the fundamental food chains of the ocean has decreased by 6% over the last three decades.
  • As oceans have warmed, oceanic nutrient deserts have expanded by 6.6 million square km’s over the past two decades.
  • Within decades, Ocean Acidification will have major impacts on temperate and polar water ecosystems. Projections show that the Southern Ocean around Antarctica will become corrosive by 2050.
  • Recent studies indicate a 14% decrease in coral growth in the Great Barrier Reef Australia since 1990, the most significant decrease in coral growth in the last 400 years.
  • Dramatically decreasing Global Greenhouse Gas Emissions by 2050 is necessary if Coral Reefs are to survive the next 50 years.
  • Creating marine protected areas (MPAs) and ending destructive fishing practices would also increase the resiliency of marine ecosystems and help them withstand acidification.
  • Evidence indicates that coral reefs in marine protected areas are less affected by global threats such as global warming and ocean acidification, demonstrating the power of eco-system protection.

Sea TurtleSea turtles were one of the very few survivors of the last Great Mass Extinction over 65 million years ago. Six of the seven species of sea turtles are now classified as endangered.
Photo Courtesy: Sean Davey