Greenhouse gases what you need to know
What’s the deal with greenhouse gases?
We explore the basics of greenhouse gases, looking at what they are, how they affect our environment, and why we need to curb emissions.
You’ll often hear the term ‘greenhouse effect’ used in relation to climate change. However, it’s actually a natural process that brings many benefits to our planet. So why is this phenomenon such an issue? And what, exactly, are greenhouse gases? We explore these issues and more.
As well as taking a look at the basics of greenhouse gases, we’ll examine what produces them, as well as their impacts on our environment and what we can do to reduce them.
What is the greenhouse effect?
Let’s start by looking at the greenhouse effect, a phenomenon that is vital to our planet and climate. In our changing planetopen step, we explore how the greenhouse gas effect works. On a simple level, it’s a process where certain gases trap heat in the Earth’s atmosphere, contributing to the warming of the planet.
Yet as we explored in our guide to climate change, the greenhouse effect is actually a natural and necessary process. Greenhouse gases in the atmosphere absorb solar radiation in the form of heat, therefore heating up the Earth. Without the greenhouse effect, Earth would have a temperature of -20°C.
However, human activity is increasing the amount of greenhouse gases in the atmosphere, meaning that more and more heat is being absorbed, which in turn drives things such as global warming, heating up the planet more than is necessary.
This phenomenon isn’t a new discovery – scientists have been exploring the greenhouse gas effect and its potential impacts on climate change since the 1850s.
What are greenhouse gases?
Let’s take a look at a greenhouse gas definition. In our open step on sustainable futures, they’re described as ‘a gaseous compound with the ability to trap heat (or longwave radiation) in the Earth’s atmosphere.’
There are several gases that fit these criteria, and many of these occur naturally in Earth’s atmosphere. These include carbon dioxide, methane, water vapour, and nitrous oxide. However, human activity is increasing the presence of some of these gases, as well as introducing synthetic compounds.
Examples of human-made greenhouse gases include chlorofluorocarbons (CFCs), hydrofluorocarbons (HFCs) and Perfluorocarbons (PFCs), as well as sulfur hexafluoride (SF6).
You can learn more about atmospheric chemistry in our free course from the University of Leeds.
The most abundant greenhouse gas
So, which gases are the main offenders when it comes to climate change? As you might expect, carbon dioxide, methane, and nitrous oxide are the most abundant greenhouse gases in our atmosphere.
If we take carbon dioxide (CO2) as an example, concentrations of the gas have risen by around 40% since the Industrial Revolution. This means that atmospheric mixing ratios for CO2 are now around 400 parts per million (ppm) compared to pre‐industrial levels of 280 ppm.
Similarly, the amount of methane in Earth’s atmosphere is also on the rise. Data from NASA’s Earth Observatory show that methane concentrations are now at 1875 parts per billion, about 2.5 times as much as was in the atmosphere in the 1850s.
However, going back to our sustainable futures open step, lesser-known gases such as tetrafluoromethane (CF4) are harming our atmosphere as well. This gas is produced when making semiconductors as well as in the aluminium industry. Worryingly, evidence suggests that CF4 is increasing global warming 7,360 times more than CO2.
Find out more about tackling environmental challenges for a sustainable future with our course from the University of York.
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