The greenhouse effect is a natural process that warms the Earths surface. When the Suns energy reaches the Earths atmosphere, some of it is absorbed by greenhouse gases such as water vapor, carbon dioxide, methane, and nitrous oxide. These gases trap the heat and keep the Earths temperature within a range that is suitable for life. The natural greenhouse effect is vital to life on Earth, and without it, the Earths surface would be approximately 33°C cooler.

The enhanced greenhouse effect, also known as climate change or global warming, is the impact on the climate from the additional heat retained due to the increased amounts of carbon dioxide and other greenhouse gases that humans have released into the Earths atmosphere since the industrial revolution. The increased concentrations of greenhouse gases trap more heat, leading to a warming effect that disrupts the Earths climate equilibrium and causes an increase in the global average surface temperatures. The main greenhouse gases whose concentrations are rising due to human activities are carbon dioxide, methane, nitrous oxide, hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), and ozone in the lower atmosphere.

In summary, the enhanced greenhouse effect is the result of increased concentrations of greenhouse gases in the Earths atmosphere due to human activities. This leads to a warming effect that disrupts the Earths climate equilibrium and causes an increase in the global average surface temperatures.