1. What changes were made based on the 1990 Clean Air Act? Choose one aspect of the 1990 Clean Air Act amendments that you think is most important and discuss how it addresses the air-quality problems in the United States.

2. Reducing sulfur content is a huge factor when it comes to diesel engines. Just think, these are the engines that move almost all of our goods and services. These engines have a much longer lifespan and run much better than gasoline powered vehicles, and get way better fuel economy (mpgs). In 2007, the EPA required all diesel fuel to be "ultra low sulfur" content. This regulation had been enacted earlier in Europe (2005), which is why several European car companies have diesel cars on the market now. Since ULSD fuel has been required, other car companies have now been manufacturing cars that run on diesel. I actually just saw a commercial for a Chevy Diesel (can't remember the model) that gets 45 mpgs on the highway. Would this increased fuel economy (and emissions), make up for the particular and NOX (nitrous oxides) that are put into the air by diesel fuel?

3. What policies should be implemented to address nutrient pollution in water resources? What are some federal and state policies that have been enacted to combat this problem.

4. The regulations of the Montreal Protocol were included in to the Clean Air Act amendments of 1990. There have been recent studies of the ozone hole that has shown that the size and stabilized and some even believe it is declining. The current scientific consensus is that the hole should complete shrink by 2050. This is interesting because I have discuss with other colleagues about the fact that the hole in the ozone actually allows gases to escape into space, thus mitigation some of the impacts of increase carbon dioxide in the atmosphere. The big question is what will happen once this hole shrinks down, will the side effect be that increased temp with go up at an even faster rate? Only time will tell.