In the context of climate feedback, is an increase in cloud cover that cools the Earth a positive or negative feedback?

• A. Negative feedback
• B. Positive feedback
• C. Neutral feedback
• D. Uncertain feedback

Answer: (A)

Cloud feedbacks describe how the climate system responds to a perturbation. When more cloud cover increases, and the result is cooling, this dampens the initial warming because the extra clouds reflect more sunlight back to space, raising the planet’s albedo and reducing the amount of solar energy reaching the surface. That dampening of the perturbation is what defines a negative feedback. Clouds can sometimes have warming effects too by trapping heat, but in this scenario the cooling effect dominates, so the response acts to oppose the change rather than amplify it.