Greenhouse gases (GHGs) have a bad reputation, as they directly contribute to the growing threat of climate change on our planet. What you might not know is that some of these gases are necessary for life on this planet, but even too many of the necessary gases can be a bad thing.
Since an understanding of greenhouse gases is important to understanding climate change and global warming, it’s helpful to answer the question, “What are the greenhouse gases?” and then dive deeper into the topic: How much is too much? Are they that bad for the planet? What role do they play in climate change? With this article, you’ll learn a greenhouse gases definition, more about what greenhouse gases are, what they do, and how they are impacting our world.
Greenhouse Gas Definition
Greenhouse gases refer to the gases that absorb and emit radiant energy within the thermal infrared range, which traps heat in the atmosphere. This phenomenon of trapping solar radiation and absorbing infrared radiation is known as the greenhouse effect—a term inspired by the greenhouses that often sustain life during colder months by absorbing radiant energy from the sun and retaining it within a glass enclosure. Thus, the greenhouse effect helps our planet stay warmer than it would be without an atmosphere.
To a certain extent, greenhouse gases like methane and nitrous oxide benefit the planet by creating a layer of protection that holds onto heat instead of allowing it to escape from our atmosphere. Without greenhouse gases, life would not be possible. The planet's temperature would drop to below 0˚F, creating an inhospitable environment for plants and animals to survive.
However, the opposite is also true: If too many GHGs are in the atmosphere and greenhouse gas concentrations increase, the planet can become too warm. This influx of greenhouse gases is what many scientists believe to be the leading cause of climate change.
Global Warming Potential of Greenhouse Gases
Greenhouse gases impact the planet in different ways, depending on their ability to absorb energy (their "radiative efficiency") and how long they remain in the atmosphere (their "lifetime").
To help compare the global warming impact of the various greenhouse gases, a measurement called the Global Warming Potential (GWP) was created. The Global Warming Potential measures how much energy the emission of 1 ton of a gas will absorb, compared to the emission of 1 ton of carbon dioxide (CO2) over a given period, usually 100 years.
The higher the GWP, the more that gas contributes to global warming compared to CO2 over that same amount of time. By creating this common unit of measurement, analysts and policymakers can create accurate emission estimates for the various gases, and compare carbon emissions and reduction opportunities across different sectors.
Examples of Greenhouse Gases
Greenhouse gases have been around longer than human life. They are part of the reason life on Earth was able to flourish, because the gases made it warm enough for plants and animals to thrive. However, if Earth gets too warm or too cold, it can harm animal and plant life, so those greenhouse gases must stay at the right proportions in the atmosphere.
Since the beginning of the Industrial Revolution, humans have started releasing more greenhouse gases into Earth’s atmosphere than needed to maintain a healthy greenhouse effect. These increased concentrations of greenhouse gases occurred through activities such as modernized manufacturing, transportation, and agricultural practices. Even worse, our industrial actions have led to the creation of new greenhouse gases that only hurt the atmosphere, which has increased the speed of global warming.
Carbon dioxide (CO2) is the most common greenhouse gas, making up nearly 75% of all greenhouse gas emissions. Atmospheric CO2 is released through natural events such as volcanic eruptions, and humans exhale it when we breathe.
The problem with carbon dioxide is that the planet has experienced a massive jump in the amount of CO2 in the atmosphere in the last two hundred years. This increase in CO2 concentrations can primarily be traced to the burning of fossil fuels to run factories and power vehicles.
Reducing our reliance on fossil fuels and switching to clean energy can help with carbon dioxide gas emission reduction.
Methane (CH4) occurs naturally through decomposition. As organic matter decomposes, it releases methane into the atmosphere, and this natural process has been happening for millions of years.
The increase in atmospheric methane over the past two centuries comes from human activities such as cattle farming, rice production, and rotting organic matter in landfills. Unfortunately, while methane only makes up around 17% of greenhouse gases, it’s much more harmful than CO2 as its GWP is about 28 times higher.
We can help reduce methane emissions by cutting back on meat consumption and reducing the amount of waste we send to the landfill.
Nitrous oxide (N2O) is another naturally occurring greenhouse gas that has recently spiked out of proportion in the atmosphere because of fossil fuel combustion. This increase can be attributed to an upsurge in the use of nitrous oxide in both commercial and organic fertilizers.
While nitrous oxide makes up only 6% of greenhouse gases, it's 265 times as strong as CO2 when it comes to its ability to warm the planet. That makes it a much more harmful gas to release into the atmosphere, especially when the levels get out of proportion.
We can reduce the amount of nitrous oxide in the atmosphere by reducing our use of fertilizers and fossil fuels.
Industrial gases, or fluorinated gases, are GHGs created exclusively by human activities. The leading culprits include hydrofluorocarbons (HFCs), perfluorocarbon (PFCs), sulfur hexafluoride (SF6), and nitrogen trifluoride (NF3). Industrial gases are primarily generated through refrigerants, air conditioning, and solvents used in manufacturing.
While these gases currently account for only around 2% of the total greenhouse gas emissions into the atmosphere, they are especially powerful in their ability to warm the planet. Industrial gases are thousands of times stronger than CO2, and they'll remain in the atmosphere for hundreds (and maybe even thousands) of years because they are not a natural part of our environment.
That means even a small concentration of these chemicals and greenhouse gases in the atmosphere can result in significant effects on global warming. Emissions of these industrial gases increased 86% in the United States between 1990 and 2019, a trend that was very dangerous for the planet.
To counteract these numbers, we need to devise methods to contain and eliminate these manufacturing byproducts before they enter the atmosphere.
Water Vapor and Ozone
Though water vapor (H2O) and ozone (O3) are technically greenhouse gases, climate scientists don’t track their numbers because they aren't typically considered to be harmful.
Water vapor, technically the most abundant greenhouse gas, only stays in the atmosphere for a couple of days before it returns to the earth in the form of precipitation, such as rain or snow.
Ozone is another greenhouse gas that can be helpful or harmful, depending on where it is in the atmosphere.
- In the part of the atmosphere known as the Ozone Layer, naturally occurring ozone gas blocks harmful UV rays from the sun.
- Holes in the Ozone Layer are areas where the ozone has thinned to the point that it can’t prevent as many UV rays from reaching Earth.
- Ozone that lives lower in the atmosphere is generated by human activity in the form of pollution or smog.
- High concentrations of ozone at this lower level can become a health hazard.
How Do Greenhouse Gases Contribute to Climate Change?
While many GHGs are naturally present in the world at certain levels, climate change can occur when the proportion of those gases in the atmosphere gets off balance. If the concentration of GHGs in the atmosphere gets too high, it traps too much heat on the earth's surface, and that leads to rising temperatures.
This increase in surface temperatures directly contributes to global climate change, and it causes issues such as:
- Extreme weather patterns
- More wildfires
- Increasing global temperatures
- Rising sea levels due to melting polar ice caps
A majority of scientists believe that human activity is the leading cause of increased levels of greenhouse gases. Thus, an overreliance on fossil fuels, overuse of industrial fertilizers, and under-regulation of manufacturing processes all have an impact on climate change.
Greenhouse Gases and Global Warming
The Earth has always had greenhouse gases, and many greenhouse gases are naturally occurring and don't bother the planet when they're kept in the proper proportions to maintain our greenhouse effect.
However, when more greenhouse gases are in the atmosphere than should be, they directly accelerate global warming. This typically happens because of human activity, especially since the most powerful greenhouse gases are created artificially.
To help reduce the level of greenhouse gases entering the atmosphere, one of the biggest changes you can make is installing solar panels on your home. To find out how much you can save, and what your impact on the planet would be, get started today with our Free Solar Design and Savings Estimate.