Author Question: To prevent the tipping point after which catastrophic environmental change will happen, what needs ... (Read 22 times)

audie · **on:** Jul 16, 2018

To prevent the tipping point after which catastrophic environmental change will happen, what needs to be done?

A) Carbon dioxide emissions must be eliminated in the next two years.
B) Global greenhouse gas levels must peak no higher than 450 ppm and start declining by 2015.
C) All greenhouse gases need to immediately be reduced below their levels in 1990.
D) Carbon dioxide emissions must not rise more than 800 ppm, double the levels in the atmosphere today.

Question 2

In general, the optimal population for harvesting

A) the maximum sustainable yield is at about half of the carrying capacity of the population.
B) the maximum sustainable yield is at about 90 of the carrying capacity of the population.
C) a plant population is quite different from the optimal population for harvesting animals.
D) any organism is independent of the carrying capacity of the environment.