There’s a delicate balancing act occurring every day all across the Earth, involving the radiation the planet receives from space and the radiation that’s reflected back out to space.
While other planets in Earth’s solar system are either scorching hot or bitterly cold, Earth’s surface has relatively mild, stable temperatures. Earth enjoys these temperatures because of its atmosphere, which is the thin layer of gases that cloak and protect the planet.
However, 97 percent of climate scientists agree that humans have changed Earth’s atmosphere in dramatic ways over the past two centuries, resulting in global warming.
Carbon dioxide (CO2) is one of the greenhouse gases. The exchange of incoming and outgoing radiation that warms the Earth is often referred to as the greenhouse effect because 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 IR 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.
Atmospheric scientists first used the term ‘greenhouse effect’ in the early 1800s. At that time, it was used to describe the naturally occurring functions of trace gases in the atmosphere and did not have any negative connotations. It was not until the mid-1950s that the term greenhouse effect was coupled with concern over climate change. And in recent decades, we often hear about the greenhouse effect in somewhat negative terms. The negative concerns are related to the possible impacts of an enhanced greenhouse effect. It is important to remember that without the greenhouse effect, life on earth as we know it would not be possible.
Greenhouse gases and global warming
Gas molecules that absorb thermal infrared radiation, and are in significant enough quantity, can force the climate system. These type of gas molecules are called greenhouse gases,. Carbon dioxide (CO2) and other greenhouse gases act like a blanket, absorbing IR radiation and preventing it from escaping into outer space.
The greenhouse effect, combined with increasing levels of greenhouse gases and the resulting global warming, is expected to have profound implications, according to the near-universal consensus of scientists.
If global warming continues unchecked, it will cause significant climate change, a rise in sea levels, increasing ocean acidification, extreme weather events and other severe natural and societal impacts.