Ocean Acidity

Evidence > Ocean Acidity

The high level of CO2 in our atmosphere brings increasing global temperatures, but it also brings another danger, increasing acidity in our oceans.

The acidity is increasing because our oceans are absorbing more CO2 and this is increasing the amount of carbonic acid in the oceans.

Here is how Ocean Surface Acidity and CO2 Levels have changed from about 1958 to 2009.

Graph: Ocean Acidity and CO2 Levels (Skeptical Science)
Graph: Ocean Acidity and CO2 Levels (Skeptical Science)

The green shows the movement of acidity:

  • The green up and down line shows the movement of the Ph in seawater.  When Ph drops, this means that acidity is rising.
  • The straight green line is the “line of best fit” for this Ph data.  It is dropping as time progresses – and this shows that acidity is rising.

The red shows the movement of CO2 levels:

  • The red saw tooth line shows movement of CO2 levels in air from Mauna Loa, Hawaii in parts per million by volume (ppmv). You can see CO2 levels dropping each northern hemisphere summer and climbing each winter.
  • The black straight line is the CO2 trend line since 1990. It is increasing over time.

This graph came from “Skeptical Science”. For a more recent version of the graph, see:
Ocean Acidification: Global Warming’s Evil Twin

The increased acidification has serious consequences.

It makes it harder for creatures like plankton to build their shells. It also makes it harder for corals to build their skeletons. At raised levels these shells and skeletons become weaker. At extreme levels of acidification, the shells and skeletons dissolve. This could lead to radical changes to life in the oceans. For example, if plankton populations drop, this limits the food for krill which limits the food for whales. Such fundamental changes in the ocean could impact millions of people who depend on the ocean for food and resources.

“If we continue to add carbon dioxide at current rates … by the end of this century … [we may have] an ocean more acidic than any seen for the past 20 million years … A more acidic ocean won’t destroy all marine life in the sea, but the rise in seawater acidity of 30 percent that we have already seen is already affecting some ocean organisms like corals and zooplankton. Smithsonian Institute & US National Museum of Natural History

It is not sustainable for ocean acidity to keep on increasing like this.

Other References

Updated 4 Feb 2018

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