Q21 - In several countries, to slow global warming, many far

[samantha.rose.shulman]

PT65, S1, Q21 (Necessary Assumption)

(D) is correct.

This is a Necessary Assumption question. This conclusion isn’t too difficult to find, since it appears at the end of the stimulus and includes "therefore" to guide us there: therefore, these incentives are helping to hasten global warming.

Before moving on to the premise(s), we might ask ourselves _ "which incentives?" It is not uncommon for conclusions to include borrowed language like this. Sometimes, we have to go back to other parts of the stimulus in order to truly understand the conclusion. In this case "these incentives" refers to incentives for farmers to plant trees on their land.

Next, we might ask "why does the author think these incentives are hastening global warming?" This would lead us to the main premise: "trees absorb and store carbon dioxide less effectively than native grasses". We have found our argument core:

Trees Absorb And Store Carbon Dioxide Less Effectively Than Native Grasses -> Tree-Planting Incentives Help To Hasten Global Warming

What are some of the necessary assumptions made by this argument? Doesn’t it seem odd that they conclude planting trees hastens global warming? They conclude this because there is a more effective strategy to absorb and store carbon dioxide _ native grasses. Therefore, a necessary assumption of this argument is that if we do not use the most effective strategy for lessening a problem, we accelerate the problem. This is quite the assumption to make. Another necessary assumption is that the more effective strategy is a viable option. In other words, the most effective strategy (native grasses) must be something we can actually do in practice; otherwise the less effective alternative wouldn’t hasten the problem.

The correct answer may be an assumption we have identified, or it may be something we haven't considered. It is important to remember, however, that the assumption we are looking for is a necessary assumption. It may not completely close the gap, but it is required by the argument, thus the Negation Test may aid us in finding the correct answer choice.

(A) is incorrect. Although this could help us reach our conclusion, it is not required.

(B) is incorrect. First, we are only talking about "many farmers" not "most farmers". Second, it doesn’t matter what the farmers would do without the incentive. In this argument the incentive exists! Eliminate!

(C) is irrelevant. Land that has been deforested? There is no mention of deforestation in our argument. This is definitely not required.

(E) is incorrect. It doesn’t matter whether governments are interested in promoting the more effective strategy (growth of native grasses).

(D) is correct. Notice that if (D) were NOT true, the argument would fall apart _ "NONE of the trees planted in response to the incentives are planted where native grasses would otherwise be growing". Then why would we care about trees vs. native grasses? This is the second assumption we identified, and is required by the argument.

[sikwong09]

Hello, I originally chose D, but later changed my answer to A. The reasoning behind this mainly concerned the word "hasten" in the conclusion.

Let's say the native grasses slow the rate of global warming at say 100 units/month, and trees slow the rate global warming at 50 units/month. The trees "absorb and store carbon dioxide less effectively" as the stim says, but the word "hasten" seems to imply a negative rate, rather than just a slower/less efficient rate. Answer A would best account for the negative rate (emitting CO2), while D doesnt.

Any help would be much appreciated!

[ohthatpatrick]

I see your point for sure.

The real issue with (A) is that we have to take a step too far to say the author MUST assume that trees emit CO2.

If we went straight from trees absorb CO2 to therefore planting trees hastens global warming, then we would be left with (A), the idea that in terms of net absorption/emission, trees actually contribute more than they absorb.

But we're really going off the idea of "trees vs. native grasses", therefore global warming hastened. So the argument hinges on the tradeoff of one vs. the other.

However, let's talk about your numerical example. The confusion is if you think we're talking about starting from scratch and deciding whether to plant native grasses or trees. In that case, we end up with +100 or +50 units of global warming prevention. So the choice to plant trees would be less effective at slowing GW but definitely not speeding up GW.

But ... we don't have to think of this as starting from scratch.

Let's picture all the things that contribute to GW as having a positive value and all the things that go against GW to have a negative value.

If the net of all these positives/negatives is positive, then global warming is getting worse. 0 means it's steady. Negative means it's getting better.

If the native grasses are already planted, they each contribute their -100 to the net effect of GW. Let's say that the net effect of GW is currently +100,000. On the whole, GW is getting worse.

If we replace the -100 force of native grasses with the -50 force of trees, then GW is now at +100,050. We have hastened GW.

If (D) read:
at least some farmers would be willing to plant native grasses instead of trees
then we would have your legitimate objection.

But, (D) is portraying a situation where native grasses are already the baseline, so swapping them out with trees is making GW worse (not just less-better).

It's kinda like if we razed the rainforest and put in houses with solar panels that absorb much of the incoming heat (but not as much as the rainforest absorbed) ... even though the solar panels do something helpful, we still created a worse situation.

Hope this helps.

[gplaya123]

I believe A is wrong because it allows some wiggle room.

A says trees absorb and emits CO2.

The question is: how much?

If trees absorb 10 CO2 but emit 1 CO2,
the net gain is 9!

If this is the case, how the hack are they "hastening" the global warming?

If it's vice versa, where it absorb 1 but emit 10 then yeah, it hastens the GW process.

So... I thought A was a sufficient condition but I just realized... it really doesn't to anything.

What do you guys think?

[joshkim700]

I see your point for sure.

The real issue with (A) is that we have to take a step too far to say the author MUST assume that trees emit CO2.

If we went straight from trees absorb CO2 to therefore planting trees hastens global warming, then we would be left with (A), the idea that in terms of net absorption/emission, trees actually contribute more than they absorb.

But we're really going off the idea of "trees vs. native grasses", therefore global warming hastened. So the argument hinges on the tradeoff of one vs. the other.

However, let's talk about your numerical example. The confusion is if you think we're talking about starting from scratch and deciding whether to plant native grasses or trees. In that case, we end up with +100 or +50 units of global warming prevention. So the choice to plant trees would be less effective at slowing GW but definitely not speeding up GW.

But ... we don't have to think of this as starting from scratch.

Let's picture all the things that contribute to GW as having a positive value and all the things that go against GW to have a negative value.

If the net of all these positives/negatives is positive, then global warming is getting worse. 0 means it's steady. Negative means it's getting better.

If the native grasses are already planted, they each contribute their -100 to the net effect of GW. Let's say that the net effect of GW is currently +100,000. On the whole, GW is getting worse.

If we replace the -100 force of native grasses with the -50 force of trees, then GW is now at +100,050. We have hastened GW.

If (D) read:
at least some farmers would be willing to plant native grasses instead of trees
then we would have your legitimate objection.

But, (D) is portraying a situation where native grasses are already the baseline, so swapping them out with trees is making GW worse (not just less-better).

It's kinda like if we razed the rainforest and put in houses with solar panels that absorb much of the incoming heat (but not as much as the rainforest absorbed) ... even though the solar panels do something helpful, we still created a worse situation.

Hope this helps.

Very unique thoughts indeed.. I will try to examine your ideas and will share my true opinions very soon.. Thanks