Inside the greenhouse the visible light is absorbed by the plants and soil and is converted into heat, which is then emitted by the plants and soil in form of infrared radiation. (scientificamerican.com)
The greenhouse effect is the process in which the emission of infrared radiation by the atmosphere warms a planet's surface. (sciencedaily.com)
The visible solar radiation mostly heats the surface, not the atmosphere, whereas most of the infrared radiation escaping to space is emitted from the upper atmosphere, not the surface. (sciencedaily.com)