▶ Your Answer :
In the reading passage, there is ample support for the author's claim that carbon sequestration can help reduce global warming. However, the professor in the lecture gives several reasons as a rebuttal to the author's point. First, the professor contends that adding iron to the ocean does not work. This is because it cannot lead to the permanent increase in the number of phytoplanktons. To explain, if the organism increase, the nitrogen that is needed to live will decrease resulting in the overall population decrease. Moreover, this method only capture 3% of the caron dioxide in the atmosphere. This counters the reading passage's claim that because the planktons feed on iron, adding iron would increase the population absorbing a lot of carbon dioxide. Second, the professor insists that artificial wetland is not a effective way to sequester carbon dioxide. According to a study, the capacity of artificial wetland is 23% lower than the natural one. In addition, it takes too long to develop. So when it becomes functional, it will be too late. This casts doubts on the reading passage's assertion that the artificial wetland reduce the amount of carbon dioxide releasing to the air by putting off the decomposition of oxygen. Third, the professor argues that coal mining also can be problematic. When carbon dioxide and coal meet, the methane is released. The methane includes carbon dioxide so if it is burned, carbon dioxide will be emitted and leak out to the atmosphere. As a result, the coal mines cannot reduce carbon dioxide at all. This refutes the reading passage's point that carbon dioxide can be captured in the coal mine for a long time. |