Critical Reasoning

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?

A. Every time a human being or other mammal exhales, there is some carbon dioxide released into the air.
B. The conversion of methane to electricity would occur at a considerable distance from the landfills.
C. 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.
D. Methane in the atmosphere is more effective in blocking the escape of heat from the Earth than is carbon dioxide.
E. The amount of methane emitted from the landfills could be reduced if the materials whose decomposition produces methane were not discarded, but recycled.

Objection says that M will be C so why burning ? But what if C is less dangerous compared to M ?

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

So this counters the objection because we are getting rid of Methane and turning it into a less effective gas in blocking the heat.

agree with logitech completely

(D)

could someone explain the methodology to do this one?

C vs D... why not C?

arora007 wrote:C vs D... why not C?

Option C talks about stopping further production of green house gases, but it didn't mention anything about the harmful effect of carbon dioxide which is still produced while producing electricity from methane. As here we have to counter the objection therefore we must look at the option which strengthens to the conformity that methane blocks more heat.

I'm still not getting what is wrong with C.

I can see how its easy to get a little lost in this one, especially since they are asking you to counter the objection.

Point: CO2 and CH4 contribute to global warming. That can be reduced by burning CH4 to make electricity.

Counterpoint: CH4 generates CO2

What you are really being asked here is to resolve the paradox. How can burning the CH4 still help the problem even though it produces another global warming gas?

A. Incorrect. All this tells us is that CO2 is naturally in the air, something we already know from the passage.

B. Incorrect. The landfill area is not the problem

C. Incorrect. What they are saying is that burning the CH4 will be used as a substitute for a non global warming contributor. So how would that help counter the objective? It would not. CH4 would still emit CO2, a global warming gas, and it would not be replacing something worse to the atmosphere. For this to be correct they would have to tell you that they are replacing a fuel that has a gas much more hazardous to the atmosphere than CO2.

D. Correct. Here they are telling us that CH4 is worse than CO2. So by burning the methane they are easing the effect on global warming, even if they do not eliminate it complteley.

E. Incorrect. Adds nothing to the issue at hand as it provides a compltely different scenario.