Whether you call it climate change, global warming, the greenhouse effect—or something else entirely—it’s no longer possible to deny the impact human activity has had on our planet. Since 1880, the planet’s temperature has risen, on average, by 0.08 degrees Celsius (0.14 degrees Fahrenheit)—with the 10 warmest years on record occurring since 2010.

The products we manufacture, the power we generate, the transportation we rely on—all of these activities, and others, create greenhouse gas emissions that ultimately find their way into our atmosphere and make the Earth hotter.

But how, exactly, do these emissions heat the planet—and what can we do to reverse the damage that’s been done? Well, that’s what we’ll discuss in this article.

Questions we’ll answer in this article include:

• How do greenhouse gas emissions affect the environment?
• What happens to the excess heat?
• Will reducing emissions slow down the progress of global warming?
• What happens after we stop emitting greenhouse gases?
• How can we reduce greenhouse gas emissions?
• Why does reducing methane matter?
• What can individuals do to reduce greenhouse gas emissions?

How do greenhouse gas emissions affect the environment?

Our atmosphere is essentially a protective bubble that surrounds the Earth. It’s comprised of gases, moisture and tiny particles that insulate us from outer space, hold the air we breathe, and help make the Earth’s surface habitable.

Each of the gases in the atmosphere serves a purpose. For example, nitrogen dilutes oxygen and protects the Earth’s surface from burning up. Carbon dioxide and methane, meanwhile, act as a “blanket” that allows some heat to remain on the Earth’s surface, rather than entering outer space.  

When these gases exist in the atmosphere in the right concentration, there is a relatively even balance between energy received from the sun, and energy emitted by the Earth—resulting in steady and habitable temperatures, and a rather predictable climate. When greenhouse gases like carbon dioxide, methane and nitrous oxide exist in higher proportions, however, the Earth’s excess energy can’t completely escape. Not only do these gases block the heat from leaving the planet, but they also absorb it and radiate it back to the Earth’s surface.

While it’s true there are plenty of natural phenomena that can cause the Earth’s “radiative balance” to fall out of whack—including things like variations in the sun’s output, volcanic activity, the Earth’s orbit and other things—scientific research has confirmed that today’s excessive concentrations of greenhouse gases in the atmosphere has been caused primarily by 50 years’ worth of human activities.

What happens to the excess heat?

When this excess heat returns to the Earth’s surface, it’s absorbed by the water and land. Warmer oceans evaporate into the air in higher amounts—creating an influx of moisture-laden air that eventually creates more intense storm systems that consist of heavier rain and snow (often in shorter periods of time). Warmer temperatures can also lead to more precipitation variability—meaning, while some areas may see more excessive precipitation, others will see less (resulting in drier conditions that can lead to increased prevalence of droughts and wildfires).

As more greenhouse gases continue to build up in the atmosphere, more heat will radiate back to the Earth’s surface—causing the impacts of global warming to inevitably get worse. Melting glaciers will cause sea levels to rise—which will place many coastal communities underwater, and displace thousands if not millions of people. Prolonged heat waves will negatively impact human health, droughts will make it difficult to consistently grow food, and more water resources will evaporate. Many plant and animal species will also be unable to survive in this new climate—leading to biodiversity loss.

But how dire this future scenario gets depends on the actions we take today. While some amount of global warming is unavoidable at this point, we can keep the consequences of climate change to a minimum—but it will require a swift, and concerted, global effort.

Will reducing emissions help to slow down the progress of global warming?

Reducing greenhouse gas emissions can slow the progress of global warming—provided we reduce our current emissions by a significant amount. The goal is to get our greenhouse gas emissions as low as possible, and then remove carbon from the atmosphere to neutralize those remaining emissions (something referred to as Net Zero). To understand why this drastic step is our only hope to mitigate the negative impacts of climate change, imagine a bathtub with the faucet running and the drain unplugged.

In this analogy, the bathtub is the Earth’s atmosphere, the running water is the greenhouse gas emissions we’re pumping into the atmosphere, and the unplugged drain is the planet’s natural ability to absorb these gases (think carbon sinks, like wetlands, rainforests, and healthy soil).

Right now, the faucet is pouring water in, full-force—faster than the drain can handle. As a result, the tub has a significant amount of water in it—and if we keep up that pace, the bathtub will soon overflow (or make the planet increasingly hotter, until it’s ultimately unhabitable for humans). Even if we slow the faucet down 50%, it will continue to add water to the tub faster than the tub can drain. The only way to stop the planet from heating up would be to allow the tub to drain completely by turning off the faucet all together (or get it down to a very slow drip)—and give the water some time to work its way down.

As this analogy demonstrates, the planet is built to absorb excess greenhouse gases—and there are things we can do to help that process along, by halting deforestation, planting more trees, and regenerating our soils. That said, these actions will be futile unless we also stop adding greenhouse emissions to the atmosphere.

What happens after we stop emitting greenhouse gases?

Once we hit Net Zero, the planet will continue to warm—thanks to emissions that already exist in the atmosphere. (Different types of emissions have different lifespans—some can remain airborne for up to hundreds of years, while others dissipate rather quickly.) As such, we can expect the global temperature to increase for a few decades before it starts to come back down.

Eliminating emissions won’t reverse the impacts of climate change either—once glaciers melt, for instance, they won’t come back. But, over time, it will allow the climate to stabilize—albeit at a higher average temperature than before. To minimize the planetary and human implications, scientists strongly recommend we keep warming under 2 degrees Celsius—ideally, 1.5 degrees Celsius.

How can we reduce greenhouse gas emissions?

Right now, there are primarily four types of greenhouse gases that are responsible for making the planet hotter:

• Carbon dioxide (CO₂) which is produced by burning fossil fuels for transportation, manufacturing and industrial processes. Things like deforestation, certain agricultural practices and soil degradation can also negatively impact the Earth’s ability to naturally absorb CO2

• Methane (CH₄) is produced in mass quantities through energy use (specifically the burning of fossil fuels and biomass fuels). It’s also created through agricultural activities (particularly the raising of livestock and cultivation of rice), as well as the anaerobic decomposition of food waste (the type of decomposition that occurs in landfills).

• Nitrous oxide (N₂O) is created through fertilizer use and fossil fuel combustion

• Fluorinated gases (F-gases) are the byproduct of many industrial processes, refrigeration, and the use of a variety of consumer products including air conditioners and foams.

Halting our production of these gases will require us to completely rethink our approach to many existing practices.

For instance, right now, energy production and use is responsible for 72% of the world’s greenhouse gas emissions—meaning if we could veer away from fossil fuel sources of energy, we could slow that bathtub faucet by quite a lot. Similarly, if all passenger cars switched to electric vehicles, we could slash the global transportation sector’s carbon footprint by 39% (approximately 3.2 billion metric tons).

Perhaps the lowest hanging fruit—the challenge that’s not all that difficult to tackle, in the grand scheme of things, and could have the greatest impact in the near-term—is reducing human production of methane.

Why does reducing methane matter?

In terms of planet-heating power, methane takes the cake. While this greenhouse gas only stays in the atmosphere for about 12 years (compared to centuries for a gas like CO2), it’s much more effective at absorbing heat from the planet—and radiating it back down to the Earth’s surface. In other words, we could dramatically reduce the rate at which the planet is warming within the next couple decades if we stopped releasing methane into the atmosphere.

Unfortunately, right now, the production of methane continues to increase steadily—with its current concentration sitting at about 2.5 times that of pre-industrial levels. Most of this methane comes from the oil and gas sector—about ¾ of which could easily be avoided at no net cost. Right now, the main thing preventing this from happening is lack of awareness and, perhaps, motivation.

Another easy fix would be to encourage more people—and more municipalities—to compost. Right now, rotting food in landfills is responsible for about 11% of global methane emissions—a number that is expected to surge by 70% by 2050, as populations increase across the globe.

Diverting food to compost facilities or backyard composts could dramatically reduce that number—because with composting, food decomposes aerobically (with oxygen), which only gives off a small amount of CO2 as a byproduct. (In landfills, food is broken down by bacteria rather than oxygen, and it’s this bacteria that give off methane.)

As an added bonus, the compost created from these composting facilities can also reduce our greenhouse gas emissions by producing healthy soil, and acting as a natural fertilizer (reducing the need for Nitrous Oxide-rich traditional fertilizers). Soil, when it’s full of microbes and rich compost, can actually act as a carbon sink—absorbing carbon from the atmosphere—while providing plants with the nutrients they need to grow. It’s also better at holding water, making it an excellent option during droughts.

When communities compost at a large scale—and when that compost is used at a large scale, such as through agricultural practices—we not only have an opportunity to dramatically reduce methane emissions, but we can also draw emissions out of the atmosphere, while growing healthier food.

What can individuals do to reduce greenhouse gas emissions?

If you’re worried about climate change, taking action can help—and composting can be an easy and affordable place to start.

Given that one pound of food waste is estimated to produce 3.8 lbs of methane—and the average American produces approximately 325 lbs of food waste per year—embracing composting on an individual level (by tossing food waste into a backyard compost rather than a green bin) can immediately slash about 1,235 lbs of methane emissions per year.

If you want to make a bigger impact, you could encourage your municipality to offer curbside composting—or even bring members of your community together to start a community composting program. Alternatively, if you live in an apartment or condo, you could push your management team to introduce a building-wide composting program.

If you’d like to learn more about how you can spread the word about composting—and encourage collective action on this issue—contact us! We’d be happy to point you in the right direction, or introduce you to some of our programs.