Detailed Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Problem:Passage: Like a blanket on a sleeping person, greenhouse gases act as insulation for the planet. The warming of the atmosphere is because of insulation by greenhouse gases. Greenhouse gases are the component of the atmosphere that moderate Earth's temperatures. Answer: insulation
Solution:
Like a blanket on a sleeping person, greenhouse gases act as what for the planet?