Table 2.
Overview of the planetary boundaries (PBs), as developed by Rockström et al. (2009) and updated by Steffen et al. (2015).
| Earth's process | Control variable | Unit | PB limits | PB uncertainty zone | Nature of limit | Current value | Status compared to the limit | Integration in LCA in literature |
|---|---|---|---|---|---|---|---|---|
| Climate change | Atmospheric carbon dioxide (CO2) concentration | ppm CO2 | 350 | 350–450 | Upper | 398.5 | Uncertainty zone | Yes |
| Change in radiative forcing | W/m2 | 1 | 1–1.5 | Upper | 2.3 | High risk | Yes | |
| Change in biosphere integrity |
Genetic diversity: extinction rate | E/MSY (extinctions per million species-year) | 10 | 10–100 | Upper | 100–1000 | High risk | No |
| Functional diversity: Biodiversity intactness index | % | 90 | 90–30 | Lower | 84 | Uncertainty zone | No | |
| Stratospheric ozone depletion |
Stratospheric ozone (O3) concentration | DU (Dobson unit) | 275.5 | 275.5–261 | Lower | 283 | Safe operating space | Yes |
| Ocean acidification | Carbonate ion concentration, average global surface ocean saturation state with respect to aragonite | % of the pre-industrial aragonite saturation state | 80 | 80–70 | Lower | 84 | Safe operating space | No |
| Biogeochemical flows (N and P cycles) | Nitrogen (N) global: industrial and intentional biological fixation of N | Tg N/year | 62 | 62–82 | Upper | 150 | High risk | Yes |
| Phosphorus (P) global: P flow from freshwater systems into the ocean | Tg P/year | 11 | 11–100 | Upper | 22 | Uncertainty zone | Yes | |
| Phosphorus (P) regional: P flow from fertilizers to erodible soil | Tg P/year | 6.2 | 6.2–11.2 | Upper | 14 | High risk | Yes | |
| Land-system change | Global: area of forested land as % of original forest cover | % | 75 | 75–54 | Lower | 62 | Uncertainty zone | Yes |
| Biome: area of forested land as % potential forest | % | 50 | 50–30 | Lower | – | – | ||
| Freshwater use | Global: maximum amount of consumptive blue water use | km3/year | 4000 | 4000–6000 | Upper | 2600 | Safe operating space | Yes |
| Basin: blue water withdrawal as % of mean monthly river flows | % | 30 | 30–60 | Upper | – | – | ||
| Atmospheric aerosol loading |
Global: Aerosol Optical Depth (AOD) | AOD | – | – | – | – | – | |
| Regional: AOD as a seasonal average over a region | AOD | 0.25 | 0.25–0.50 | Upper | 0.30 | Uncertainty zone | – | |
| Introduction of novel entities | Not defined yet | – | – | – | – | – | – |