What is it?
The Earth works on a myriad of different processes, all balanced delicately, perfectly, to make our world work without killing all life on it. One of these processes, arguably one of the most important, is the greenhouse effect. The greenhouse effect is what allows heat to be trapped on the Earth, preventing it from turning into a frozen wasteland. Conversely, it is balanced so that the Earth is able to lose heat as well, keeping our world from becoming a blazing hellscape.
The Sun is the primary source of energy, and therefore heat, for Earth. This energy takes the form of sunlight, penetrating the Earth’s atmosphere to warm and light up our world. Sunlight is able to do this because it is an electro-magnetic wave, mainly composed of infrared rays, visible light, and ultraviolet rays.
Ultraviolet rays can, and often are, harmful to humans, though they do have some benefits as well. Thankfully, most ultraviolet light is filtered out by the Earth’s atmosphere, preventing most of the harmful effects of the rays. It is filtered out specifically within the ozone layer of the earth’s atmosphere. The remaining rays will reach the planet alongside the visible and infrared light and warm the Earth’s surface. Both visible light and infrared have a longer wavelength than ultraviolet light. (they are, essentially, wider and slower than UV rays). Visible light allows people to see and is bounced around the Earth at incredibly high speeds. The infrared rays are “long” enough that they are reflected by the heated surface of the Earth.
Now, this reflection is where an integral part of the greenhouse effect comes into play. While the light initially hitting the Earth does warm it to some degree, it is not enough to keep the temperature at a safe, sustainable place to sustain life for any long-term amount of time. When the different types of light are reflected (especially infrared), back out in the direction of space, they have to escape Earth’s atmosphere. Many of them do not make out to space on their first try. Instead, they are absorbed by the many gases comprising the air and the atmosphere. These light rays are then re-radiated out in all directions, with many shooting back towards Earth. Due to the exorbitant amount of energy contained within light, these rays continue to heat the Earth, expending energy with their movements. These rays continue this bouncing until they eventually escape the Earth’s atmosphere. This process is what is called the Greenhouse Effect.
The gases in the atmosphere who possess the ability to absorb the infrared rays are called greenhouse gases. Most are the natural products of different processes of our world. Some also are caused by human activity and have been the cause of much contention in recent years. Regardless, the major greenhouse gases are vapor, carbon dioxide, methane, nitrous oxide, ozone, and chlorofluorocarbons.
The concept of the greenhouse effect was first theorized in 1824 by a scientist named Joseph Fourier. His experiments and research hinted towards this theory, but no definitive evidence was discovered. John Tyndall, another scientist, took these theories further. He was the one who discovered how heat radiations from light affect and are affected by the gases in our atmosphere. He proved the phenomena of the greenhouse effect empirically in 1859.
Enhanced Greenhouse Effect:
In recent years, human industry has created a plethora of greenhouse gases, all merging with the existing layer of greenhouse gases in the atmosphere. Carbon dioxide is one of the most dangerous greenhouse gases and also one of the most produced by industry today. It is consistently comprises over 80% of the greenhouse gases produced by the United States each year. The effect of carbon dioxide over the temperature of the Earth was studied by a Swedish Chemist named Svante Arrhenius. He published a paper called “On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground” that quantified the effect carbon dioxide had upon the temperature of our world.
Link to article: https://www.rsc.org/images/Arrhenius1896_tcm18-173546.pdf
The greenhouse effect is often divided into two parts. The Natural Greenhouse Effect is what was discussed previously. It is what the Earth does on its own through carefully designed natural processes to keep the Earth warm. Like many other cycles on Earth, it is a delicate balance, each ripple changing it potentially causing damage in many other parts of the Earth.
The part of the greenhouse effect not caused by the Earth, but by humans, is called the Human Enhanced Greenhouse Effect. The worry is that, through carbon emissions among other things, that humanity is causing the Earth to warm up. This supposed phenomena is called Global Warming. It is considered to be one of the greatest threats to the natural world today.
Much study is being done on the effect global warming could have upon the Earth, and if it occurs, the results would be catastrophic. The ice caps and glaciers will melt, destroying several ecosystems, as well as causing the sea level to rise. This would kill thousands of species of animals as well as destroying the coastlines around the world as buildings slowly become submerged in water.
Many countries around the world are taking notice of this potential disaster and are taking steps to mitigate its effects. Specifically, they regulate carbon dioxide emissions. Electric cars are a step in this direction.