PT150 S1 P1 Q5 ExplanationThe Greenhouse Effect

Answer choices, explained

1. A

   Out of Scope: Observations5% picked this

   to provide an example of a set of observations that has been predicted

   This highlighted portion doesn't contain any observations predicted by a theory. The word 'observations' in the context of a theory's predictions means 'empirical data'. "Were the observed data aligned with the theory's predictions?" We're not getting a set of data points. We're getting an explanation about how scientists fixed their theory (to account for sulfates) and an update that the theory's predictions now do match our observations about the temperatures in recent decades. This sort of trap answer is stuck within the Detail, whereas the correct answer on Local Purpose is all about the Big Idea language that bookends the detail.

   5%
2. B

   Opposite2% picked this

   to argue that a new theory will need to be formulated in order to accommodate

   This section is arguing that the Greenhouse Theory is looking stronger than ever, now that they realized their failure to account for sulfates was throwing off the numbers. They've tweaked the theory and now it makes predictions that do accommodate data from recent decades.

   2%
3. C

   Opposite8% picked this

   to demonstrate the degree to which a previously accepted theory fails to account

   It was never said that Greenhouse Theory was previously accepted. Some proponents believed it but its early models were not matching observed data. And this section is arguing that the Greenhouse Theory is looking stronger than ever, now that it accounts for sulfates, which were throwing off its numbers.

   8%
4. D

   Correct82% picked this

   to show that a certain theory that was previously in doubt can be defended in

   Why this is right

   This is supported by the previous two sentences (which is where we look for a match on Local Purpose questions). The first sentence of the 2nd was saying that the greenhouse theory was previously in doubt because its models did not match the observed data; they were too alarmist. The second sentence of the 2nd is saying that new methods are allowing greenhouse theorists to refine their models. The calculable cooling effect of sulfates is the additional data they needed, which is explained in the highlighted portion.

   Skill tested: Local Purpose · how this choice captures the passage's function is the move to repeat next time.

   82%
5. E

   Out of Scope: two competing theories2% picked this

   to propose a way of resolving a dispute between proponents of

   There aren't two theories being discussed in this paragraph. Just one theory, in two different time periods: Old greenhouse, which didn't account for sulfates and thus made bad predictions, and New greenhouse, which has rectified the situation.

   2%