10.1 pollution levels over time

Question 1

what has happened to US pollution levels as we have changed our policies?

Answer 1

• air is cleaner than in the 80s
• forested area is increasing

Question 2

why is it misleading to look at total output?

Answer 2

you have to take into account that the population is growing

Question 3

misleading: cancer cases

Answer 3

data on total cancer cases has been growing

MISLEADING!

have to take into account that population is growing AND on avg people live longer which means they live long enough to die from cancer instead of other causes

Question 4

However, the real question should be “how much better are we as compared to the baseline?”

Answer 4

For many pollutants, the rate was already falling before any official policy response by the government

examples:
- SO2 levels
- indoor air quality
- CO2 levels
- GHG
- Atrazine