What causes the Greenhouse Effect?

The Greenhouse Effect is primarily caused by greenhouse gases trapping heat close to Earth's surface. These gases, which include carbon dioxide, methane, and nitrous oxide, allow sunlight to enter the atmosphere but prevent some of the heat that the Earth emits from escaping back into space. This process helps to maintain a temperature that supports life on the planet.

In the context of the other options, while excessive cloud cover can have an impact on climate by reflecting sunlight, it does not specifically relate to the mechanism of the Greenhouse Effect. Air pollution blocking solar radiation may affect weather patterns, but it does not describe the heat retention process that characterizes the Greenhouse Effect. Deforestation can increase carbon dioxide levels but is more of a contributing factor to climate change rather than a direct cause of the Greenhouse Effect itself. Therefore, the trapping of heat by greenhouse gases is the key factor in understanding why the greenhouse effect occurs.