TASK DEFINITION: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
PROBLEM: Compression zones is the opposite of rarefaction zones, where air molecules in waves are loosely packed.

SOLUTION: What is the opposite of rarefaction zones, where air molecules in waves are loosely packed?

PROBLEM: Renewable energy sources emit fewer or no greenhouse gases.

SOLUTION: What type energy sources emit fewer or no greenhouse gases?

PROBLEM: Air pressure it decreases as altitude increases.

SOLUTION:
How does air pressure change as altitude increases?