GEOLOGY

Detailed explanation-1: -Without the naturally occurring greenhouse gases (principally water vapor and CO2), the earth’s average temperature would be nearly 35°C (63°F) colder, and the planet would be much less suitable for human life.

Detailed explanation-2: -’Greenhouse gases’ are crucial to keeping our planet at a suitable temperature for life. Without the natural greenhouse effect, the heat emitted by the Earth would simply pass outwards from the Earth’s surface into space and the Earth would have an average temperature of about-20°C.

Detailed explanation-3: -According to scientists, the average temperature of Earth would drop from 14˚C (57˚F) to as low as –18˚C (–0.4˚F), without the greenhouse effect. Some greenhouse gases come from natural sources, for example, evaporation adds water vapor to the atmosphere.

Detailed explanation-4: -The IPCC evaluates the risk of climate change caused by human activities. According to the IPCC’s most recent report (in 2007), Earth’s average surface temperatures have risen about 0.74 degrees Celsius (1.33 degrees Fahrenheit) during the past 100 years. The increase is greater in northern latitudes.

Detailed explanation-5: -Greenhouse gas molecules in the atmosphere absorb light, preventing some of it from escaping the Earth. This heats up the atmosphere and raises the planet’s average temperature.