Ocean Acidification
The chemistry of the ocean is changing faster than at any point in millions of years.
Severity score
54.1
Severe · default weighting
Trajectory
Worsening
What this is
The ocean has absorbed roughly a quarter of human carbon emissions, lowering pH and reducing the carbonate that shell-forming organisms need. Effects cascade through fisheries that supply protein to billions of people, and the change is effectively irreversible on human timescales.
Score breakdown
Loss of life
6Direct and attributable mortality, normalised across annual and cumulative tolls.
Lives negatively impacted
72People displaced, injured, food-insecure, exposed or otherwise materially harmed.
Financial cost
62Direct damage, lost output and health-system spend attributable to the event.
Environmental impact
94Emissions, habitat and biodiversity loss, contamination and irreversibility.
Trajectory
78Whether the situation is escalating, and how much worse it is plausibly getting.