One approach is to study the effects of ozone on a cultivar of tobacco that is extremely ozone-sensitive. We can learn about long-term effects by growing varieties of clover, tomato, and selections of milkweed, which respond more slowly. But those are the conditions that plants are normally exposed to. Normal conditions produce the most reliable results. But even then, it will be 10 years before any clear findings are generated from the experiments, Manning said.
Funding is also a problem.