I wholeheartedly concur Kelly that one of the big environmental problems is water-shortage in our world, because there are still half countries and areas facing no clean water to use. Moreover, I would add that the daily waste produced on earth is too much to solve it. For instance, America and Europe have stopped their garbage export due to China implement banning to it. Furthermore, the best approach to deal with such a lot of waste is by implementing waste management in each, educating their citizens sorting their trash like plastic, glass, metal and so on. Those measures not only reduce the amount of garbage that ends up in landfills, but also promote everybody' s awareness of environmental protection. Admittedly, Paul proposes a relevant point that the polluted air produced by gasoline cars is the most serious problem. However, he does not mention that there is an increasing number of electric vehicles replacing the gasoline counterpart, and it' s become a trend that cannot be reversed. Therefore, air pollution won' t be a problem in the future. Overall, I firmly believe that we can build a waste categorization system to fix waste pollution problems.