Future Update

Revised 7/25/2017

An attempt to add better resolution to the backcast has yielded a new analysis using its limit-seeking and global warming assumptions (see calculation detail, below). As before, there is no avoiding a peak in global population and consumption where growth is sought for either or both.

The following graph shows the results over the course of this century, beginning in 2015 (historical values are shown prior to that year). Population is given as a percentage of its historical value in 2015, and values of happiness are shown directly.

Three sets of projections appear here:

• Worst P and Worst H are the most drastic declines in population and happiness due to maximum global warming impact
• Best P and Best H is the most optimistic set of values for population and happiness due to no global warming impact
• Mid P and Mid H are population and happiness with global warming impact half that of the worst case.

Population and consumption (per-capita ecological footprint) are assumed to progress and be limited as in the backcast.

A new feature in these calculations is the use of projections of annual change in population and consumption. These have been found to vary with the overall amount of ecological resources consumed (population times per-capita consumption).

The following graph shows this in terms of the fraction of total resources; solid lines are projections and points are historical data.

Roll over the image for the full range of the projections, which show we are limited to 60% of total resources and are based on:

• Population and consumption at their historical levels in 2015
• No global warming impact
• No ecological limits (other species providing products and services)