How do greenhouse gases contribute to global warming?

Greenhouse gases contribute to global warming by absorbing infrared radiation and trapping heat within the Earth's atmosphere. When solar radiation reaches the Earth, some of it is absorbed by the surface, warming it. The Earth then emits this energy back into the atmosphere in the form of infrared radiation. Greenhouse gases, such as carbon dioxide, methane, and water vapor, absorb some of this infrared radiation and re-radiate it in all directions, including back towards the Earth's surface. This process creates a "greenhouse effect," effectively warming the atmosphere and resulting in an increase in global temperatures.

The other options do not accurately describe the role of greenhouse gases. Reflecting sunlight away from the Earth would actually have a cooling effect, while increasing the Earth's albedo would also lead to lower temperatures rather than contributing to warming. Cooling the atmosphere contradicts the fundamental mechanism by which greenhouse gases operate, which is to trap heat rather than dissipate it.