PASSAGE 14 (Questions 1-5)

Directions: In the below given passage, there are blanks each of which has been numbered. Five words are suggested, one of which fits the blank appropriately. Find out the appropriate word in each case.

Greenhouse gases are only __(1)__ of the story when it comes to global warming. Changes to one part of the climate system can __(2)__ additional changes to the way the planet absorbs or reflects energy. These secondary changes are __(3)__ climate feedbacks and they could more than double the amount of warming caused by carbon dioxide alone. The primary feedbacks are __(4)__ to snow and ice, water vapour, clouds, and the carbon cycle. Perhaps the most well __(5)__  feedback comes from melting snow and ice in the Northern hemisphere. 

[IBPS(PO), 2012]

Select the appropriate word for blank 1.