Global Indicators of Stress:

• Rapid Pop growth (from 2 to 6 B in last century; peaked in 1985-90 at 90 m/yr)
• Differences between developed and developing countries increasing, with highest pop growth in less developed countries, reducing or stagnating per capita production, income and consumption.
• Increased waste from production/consumption system (pollutants)
• Increased transformation of land (e.g., de-forestation); loss of species.

Some Positive indicators:

• Development (per capita or per land area economic productivity) – still big differences between most and least developed—see Fig. 1.5
• Reduced some pollution types in most developed countries
• Population growth RATE declining---see Fig. 1.2

OK, so are headed for a brick wall?

Carrying capacity: the absolute limit on the number of an organism that a habitat can sustain indefinitely. Global for people? Depends on technology/consumption.

Are we there yet?

Pop doubled since 1965 (from 3 to 6B)---per capita food production also increased (.5%), but some say it declined a percent since 1990.

So, reasonable people (as well as extremists) will disagree, but the worst-case scenarios from the 1970s appear to have been wrong (the "Limits to growth" debate).

Cultural carrying capacity: sustainable population at reasonable quality of life, with no net degradation of environment.

Discuss Fig. 1.8