Planetary Boundary

Ocean Acidification

Global Status in 2009

Limit per Capita:
28.8 Gigatons of CO2
7.2 Gigatons of CO2
1.1 Tons CO2
clearly safe    safe    unsafe    clearly unsafe

Score < 1x: --
Score < 2x: Brazil, India, Indonesia
Score < 4x: Bulgaria, China, Hungary, Latvia, Lithuania, Mexico, Portugal, Rest of the World, Romania, Turkey
Score < 8x: Estonia, France, Germany, Italy, Japan, Malta, Poland, Republic of Korea, Russian Federation, Slovakia, Slovenia, Spain, Sweden,
Score < 16x: Austria, Cyprus, Czech Republic, Belgium, Denmark, Finland, Greece, Ireland, Luxembourg, Netherlands, United Kingdom of Great Britain and Northern Ireland
Score < 35x: Australia, Canada, USA
Countries with a score of 1 are in equilibrium, i.e their footprint is the same size as their limit. Countries with a score larger than 1 are overshooting, i.e. their footprint is exceeding their allocated limit.
The yearly global limit for Ocean Acidification is largely overshot and the situation is thus considered unsafe. 100% of the global population is leaving in a country overshooting this limit.

At the current yearly rate of global emissions, the global budget will be exhausted in 20 years, by 2035. The gravity of the situation is thus very comparable to Climate Change. While high-income economies show a much large overshoot, this is true for all countries and middle- and low-income should also reduce their carbon dioxide emissions.
Name (evaluation year)
Ocean Acidification (2009)
What are the objectives of this Planetary Boundary?
To avoid the “conversion of coral reefs to algal-dominated systems, the regional elimination of some aragonite - and high-magnesium calcite - forming marine biota” (Rockström et al., 2009), as well as the negative effect on marine carbon sink.
Is this a global issue?
Ocean Acidification is caused by CO2 emissions, which are also the main cause of Climate Change. Ocean Acidification is a global issue since CO2 emissions are accumulating in the oceans whatever their location of origin. Its effects are also global, albeit with regional variations.
What is the selected indicator?
The remaining cumulative emissions of carbon dioxide (CO2) from human activities to maintain an acceptable calcium carbonate saturation state Ω.
How is the indicator computed?
Equal rights to emit carbon emissions are assumed for all inhabitants of Earth in 2005. These rights, i.e. the global limit, are computed as a budget of remaining carbon emissions to maintain an acceptable calcium carbonate saturation state Ω. To consider past emissions and future rights to emit, a limit is then computed per country for later years. An equivalent right to emit is assumed between the inhabitants of a country until 2100, where emissions are assumed to be 0.

A detailed description of the logic and the computation is available in our methodological report.
Data sources, and resulting limits and footprints, differ however from the report since we have here used global and more recent databases.
We have here mainly used the following databases: EDGAR, WIOD, World Population Prospects: The 2012 Revision.

Look at the big picture !

Current results represent first estimates of the performances of countries with respect to Planetary Boundaries. Computations are based on international datasets included in world input-output models (WIOD and exiobase 2.0) which we complemented with additional sources and basic assumptions.

The overall perspective is assumed to be correct but errors could exist for specific countries. Results will be improved in the follow-up projects.