GWD-6-32

Q32:

Proposal:  Carbon dioxide and methane in the atmosphere block the escape of heat into space.  So emission of these “greenhouse” gases contributes to global warming.  In order to reduce global warming, emission of greenhouse gases needs to be reduced.  Therefore, the methane now emitted from open landfills should instead be burned to produce electricity.

Objection:  The burning of methane generates carbon dioxide that is released into the atmosphere.

Which of the following, if true, most adequately counters the objection made to the proposal?

1. Every time a human being or other mammal exhales, there is some carbon dioxide released into the air.


2. The conversion of methane to electricity would occur at a considerable distance from the landfills.


3. The methane that is used to generate electricity would generally be used as a substitute for a fuel that does not produce any greenhouse gases when burned.


4. Methane in the atmosphere is more effective in blocking the escape of heat from the Earth than is carbon dioxide.


5. The amount of methane emitted from the landfills could be reduced if the materials whose decomposition produces methane were not discarded, but recycled.

以下是引用oliviachen在2004-9-10 17:54:00的发言： to miaoyin_tx ， 偶不是牛NN。M的危害比二氧化碳大，那么把M转换成二氧化碳危害相比要小，得到改进了 D. Methane in the atmosphere is more effective in blocking the escape of heat from the Earth than is carbon dioxide. if it's D, then the global warming will be increased rather than reduced.  what you think? following is the old discussion: http://forum.chasedream.com/dispbbs.asp?boardid=24&id=56105&star=1#606135

D is the best answer.

D says, Methane in the atmosphere is more harmful than carbon dioxide, since M is more effective in blocking the escape of heat from the Earth -- thereby contributes more to the global warming.

So, burning M into CO2 coverts something very bad to something less bad, and is a good thing to do.  In other words, D offers evidence to counter the objection and strengthen the original argument.

"Methane in the atmosphere is more harmful than carbon dioxide, since M is more effective in blocking the escape of heat from the Earth "

不明白，既然Methane in the atmosphere is more harmful than carbon dioxide，为什么M is more effective in blocking the escape of heat from the Earth ，那应该是最有用喽？

blocking the escape of heat from the Earth 到底是产生温室效应还是避免温室效应