A greenhouse gas is a type of gas that contributes to the greenhouse effect. In other words, these gases – like carbon dioxide, water vapour and methane – contribute to a warmer climate. This is because they have the ability to absorb the heat from the sun. They catch the heat from the sun rays which then results in a warmer climate. Too many greenhouse gases results in global warming. This is the biggest issue of the current the climate crisis.
Global Warming Potential
The Global Warming Potential, GWP, is a type of scale used to compare the abilities of the emissions of different greenhouse gases. It compares the ability that carbon dioxide (CO2) has to absorb the heat from the sun, with other gases. In order to get an understanding of the dangers that a gas might have in relation to global warming.
The GWP is calculated by using 3 factors. The primary one is how effective the gas is to absorb the heat from the sun. The second factor investigates how long the gas can stay in the atmosphere. For instance, between 15-40 % of the carbon dioxide has the ability to stay in the atmosphere for over 1000 years.
The third factor is slightly more complicated to understand. It considers which parts of the infrared wavelength range that allows a gas to absorb the most heat. In other words… if you imagine a sun ray entering from space to earth, in a straight line, some parts of this line will allow a gas to absorb more heat than other parts. This is because the atmospheres own ability to absorb the heat is stronger in some places. While weaker in some. The third factor can lead to a gas with a lower GWP since it cannot absorb much heat in these places.
For example, the greenhouse gas nitrous oxide (commonly known as laughing gas) has a 300 times stronger GWP than CO2. This means that laughing gas absorbs way more heat than CO2. However, the latter is a much more common greenhouse gas. Which is why one takes more about the emissions of CO2.
The greenhouse gas CO2
As mentioned carbon dioxide is the most famous greenhouse gas. It is released through the breathing of humans and plants. As long as organisms living on the surface of the earth lives and dies in a natural cycle, the level of carbon dioxide remains balanced. However, human activities disturb this balance. For example, the burning of fossil fuels releases enormous amounts CO2. Transport, such as cars and airplanes, are also a huge source of emissions. They are part of why we have a problem with global warming.
Nitrous oxide (laughing gas)
The formula for laughing gas is N2O. It is also known as nitrous. It is a colourless gas that is commonly used within healthcare. For example, in settings such as births and dental care. More so, laughing gas can be used to increase the shelf life of food. As well as increase the combustion effect in engines. As previously mentioned, the gas is an extremely powerful greenhouse gas. It has a GWP of near to 300 compared to CO2. In other words, it is 300 times better at absorbing the heat of the sun and contribute to a warmer climate. Luckily, it is released in much smaller quantities than CO2.
Methane has the formula CH4. It has a GWP of 25, meaning it too is stronger than CO2. Although, methane does not stay as long in the atmosphere as other gases, which is considered positive for the earth’s climate. Methane is released by human activities that are related to farming. A huge part of the emissions come from the production of meat and dairy products. Methane also exists in little bubbles contained in glaciers and the big poles. In other words in ice. Therefore, a lot of methane is released as the icecaps of the world are melting. The releases of methane contribute to a warmer climate, which melts the ice in an even faster rate. This kind of process is known as a “feedback-effect”.
Other greenhouse gases
Even water vapour is a greenhouse gas, it actually stands for about 2/3 of the natural greenhouse effect.