Ocean Acidification

When excess CO2 from burning fossil fuels enters the atmosphere, the OCEAN absorbs about 25% of it. Sounds helpful — until you realize CO2 + water makes carbonic acid. The ocean's pH has dropped about 0.1 units since the Industrial Revolution (more acidic). That sounds tiny but on a logarithmic scale, that's a 30% increase in acidity. This is OCEAN ACIDIFICATION.

Why it matters. SHELLFISH (clams, oysters, snails) and CORAL build their structures from calcium carbonate. In more acidic water, building (and maintaining) these structures becomes harder. Some shells DISSOLVE in highly acidic conditions. Coral reefs — the rainforests of the sea, supporting 25% of marine species — are at major risk. PLANKTON and shell-building plankton at the base of food webs are also affected. The whole ocean ecosystem is potentially threatened.

What can be done. (1) REDUCE CO2 emissions globally — the root cause. (2) PROTECT critical ecosystems (coral reefs, oyster reefs) so they have the resilience to adapt. (3) RESEARCH heat- and acid-tolerant coral varieties. (4) RESTORE seagrass and kelp forests (they absorb CO2). (5) Monitor and study ocean chemistry. The long timescales of ocean chemistry mean even if we stopped emissions today, acidification would continue for decades.

Ocean acidification is one of the great hidden challenges of our time. The ocean has been our climate buffer — but at the cost of its own chemistry. Reversing course requires reducing emissions and protecting marine ecosystems.