Dakota and montana are discussing fossil fuel usage. dakota remarks that carbon emissions are up 20 percent. montana questions the assumptions and possible hidden values behind this claim. montana is engaging in thinking.

montana is engaging in  Critical thinking.
Critical thinking refers to the process of using objective/scientific reasoning in order to create a decision/ judgment.
In order to do this, we need to refuse to take all statement that describes an occurrence on face value and consider all the factors that might influence that occurrence in order to find the truth.

productive most commonly means: achieving or producing a significant amount or result.

explanation:

productive can also mean:

producing or giving rise torelating to or engaged in the production of goods, crops, or other commodities.

these depend on how the word productive is used. most likely productive will mean   achieving or producing a significant amount or result.