1. Homework #2
The following problems are out of the textbook “Industrial Ecology”
1. Problem 2.3
Answer: (Example of aluminum)
year Pop(billion) Al(million tons) Al per capita (g/person)
2. Problem 2.4
Answer: 2000: 23; 2010: 14 g; 2020: 6.2 g SO2/dollar
Hint: Use extrapolation beyond the curves of Fig. 2.8)

2. Homework #2 3. Problem 3.2 Answer: 1.5%(current fraction),
Answer: Draw a vertical line from 1.1 mg/l, and picture moving all of the curves to the right by half a division (i.e., factor of three in the log). The intersection is with the log probit curve. The Weibull model would have given approximately 2*104 µg/l as the standard, the logit model approximately 0.3 µg/l, and the multistage model approximately 30 µg/l.