Compare the reasons from the lecture and passage about "Cloud Seeding"
The passage discusses a process called "Cloud Seeding". It refers to the procedure of spraying silver iodide to the clouds in order to decrease the amount of hail, Which has been a constant problem for the farmers in the United States, since they are heavy, hard, and they damage crops while falling from the sky. The passage brings three reasons to support that this method was indeed effective in reducing hail fall. The lecture, however, suggests that none of the reasons from the passage prove the effectiveness of cloud seeding. Firstly, according to the article, a few laboratory experiments show that adding silver iodide to the water vapor close to its freezing point may turn it to snow flakes, which are so much more lighter than hail pellets. On the other hand, the professor points out that situations may be different in real life. Since silver iodide will prevent the formation of all types of precipitations, they may instigate a period of drought and harm the crops in another way: lack of irrigation. Second, the article explains that there is evidence from urban areas in some Asian countries that have documented the functionality of cloud seeding. And if they have worked previously in other regions, they can also work in the US agricultural districts. The professor rejects this idea by explaining that the atmosphere of these urban areas ins Asia are often polluted. The gas composition of the pollution actually has positive effects on the procedure of cloud seeding. In other words, we cannot be a hundred percent sure that it might work in farming areas of the US which are unpolluted. Lastly, a little number of local studies back up this idea that cloud seeding works. for example, a research ran in the centeral US found that the damage to the crops due to hail fall plummeted when they incorporated cloud seeding in that region. The lecture proposes that the neighboring areas of that particular region have also been effected, so we can infer that this shift in the rate of hail fall had no relations to the cloud seeding and it was a result of natural process.
Submitted by Witch Doctor on