The following cases are based on the Half-Earth Hypothesis, and representative future trajectories of basic variables (population, life expectancy, ecological footprint per person, and global ecological footprint). Click on the links for details.
| Case |
Description |
| Best |
No population loss; global footprint drops to sustainable level. |
| Worst |
All ecological resources are used up and population crashes. |
| Projected |
Curve-fit of present trends, assuming limited ecological resources. |
| Hybrid |
Modified Projected Case, where population is held constant at first minimum. |
| Limitless |
No limits to population , life expectancy, or ecological resources. |
| Combined |
Mix of the above cases, with each weighted according to its expected probability of being real. |
| Limit-Seeking |
Population and footprint are adjusted to approach limits based on historical trends. |
| Limit-Seeking Reference |
Default Limit-Seeking and Limit-Seeking with self-sustained global warming, 2015-2045. |
| Worst Climate |
Non-linear self-sustained climate change acting as an additional global footprint. |
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