The Greenhouse Effect and Global Warming: Definition, Causes, and potential effects to humans, Plants, animal communities and natural resources. Discuss with illustrations.

INTRODUCTION There's a delicate balancing act occurring every day all across the Earth, involving radiation the planet receives from space and the radiation that's reflected back out to space. Enormous amounts of radiation, primarily from the sun strikes the Earth's atmosphere in the form of visible light, ultraviolet, infrared and other types of radiation that are invisible to the human eye. About 30 percent of the radiation striking Earth's atmosphere is immediately reflected back out to space by clouds, ice, snow, sand and other reflective surfaces, according to NASA (National Aeronautics and Space Administration). The remaining 70 percent of incoming solar radiation is absorbed by the oceans, the land and the atmosphere. As they heat up, the oceans, land and atmosphere release heat in the form of infrared thermal radiation, which passes out of the atmosphere and into space.
It is this equilibrium of incoming and outgoing radiation that makes the Earth habitable. Without this balance, the greenhouse effect sets in.

Definition
Greenhouse Effect: The warming of the atmosphere due to the increased amounts of greenhouse gases such as carbon dioxide, nitrous oxides and methane. These gases form a blanket over the Earth, trapping the energy or heat from the sun and preventing it from leaving the atmosphere. A greenhouse works in much the same way-Incoming UV radiation easily passes through the glass walls of a greenhouse and is absorbed by the plants and hard surfaces inside. Weaker Infrared radiation, however, has difficulty passing through the glass walls and is trapped inside, thus warming the greenhouse. This effect lets tropical plants thrive inside a greenhouse, even during a cold winter.