Table 1 Planetary boundary framework as applied in this paper
From: Exploring pathways for world development within planetary boundaries
Planetary boundary | Planetary boundary indicator | Pressure indicator | |||||
|---|---|---|---|---|---|---|---|
Earth system process | Control variablea | Planetary boundary | Upper end of uncertainty zone | Reference | 2015 value | Indicator | 2015 value |
Climate change | Forcing – GHGs (W m−2) | 1.9 | 2.6 | 0 | 2.36 | GHG emissions | 53.3 Gt CO2-eq |
Stratospheric O3 depletion | O3 concentration (DU) 60–90° S | 276 | 261 | 330 | 280 | CFC-12 (Freon) emissions | 15–25 Gg yr−1 |
Atmospheric aerosol loading | Average PM2.5 concentration (μg m−3) | 10 | 25 | 5 | 21.9 | BC emissions | 11 Mt BC yr−1 |
Ocean acidification | pH | 8.01 | 7.94 | 8.2 | 8.05 | CO2 emissions | 38.4 Gt CO2 |
Biogeochemical flows | |||||||
N | N balance (Tg N yr−1) | 62 | 82 | 0 | 131.5 | Total fertilizer application | 155.3 Tg N yr−1 |
P | P balance (Tg P yr−1) | 6.2 | 11.2 | 0 | 12 | ||
Freshwater use | Water consumption (km3) | 4,000 | 6,000 | 0 | 3,440 | Water consumption | 3,440 km3 |
Land system change | Area of forested land (Gha) | 45 | 33 | 64 | 39 | Agriculture area | 48.3 Gha |
Change in biosphere integrity | MSA | 0.90 | 0.60 | 0.95 | 0.54 | Global mean temperature increase, atmospheric N deposition, land use | |
