Will global climate change make you sneeze as well as itch? Scientists studying the effects of you sneeze as well as itch? Scientists studying the effects of rising $\mathrm{CO}_{2}$ levels have looked at ragweed, whose pollen is the primary allergen for fall hay fever. They grew ragweed in three levels of $\mathrm{CO}_{2}$ a pre-industrial concentration of $280 \mathrm{ppm},$ a year 2000 level of 370 ppm, and a projected level of 600 ppm. They found that pollen production increased by $131 \%$ and $320 \%$ in the plants exposed to the recent and projected $\mathrm{CO}_{2}$ levels, respectively. What was the hypothesis of this experiment? Do the results support the hypothesis? Given what you know about global climate change, what other variables would you like to test, and what other measurements would you like to take?