## Climate Change and Greenhouse Gases

Climate change is a serious and growing problem, and greenhouse gases are its main cause. These gases have always been present in our atmosphere and help make Earth a livable planet, but in the last few hundred years, fossil fuel use has raised atmospheric concentrations and warmed the planet.

But what exactly are greenhouse gases, how do they warm the planet, and how can we reduce the amount we produce and avoid the worst effects of climate change? We take a closer look below.

## Greenhouse Gas Definition

What are greenhouse gases? Greenhouse gases absorb and emit heat energy, trapping it in the atmosphere. This phenomenon of trapping solar radiation and absorbing infrared radiation is known as the greenhouse effect. Thus, the greenhouse effect helps our planet stay warmer than it would be without an atmosphere.

To a certain extent, greenhouse gases benefit the planet by creating a layer of protection that holds onto heat instead of allowing it to escape from our atmosphere. However, if greenhouse gas concentrations in the atmosphere get too high, the planet can become too warm. This is 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").

A measurement called the [global warming potential](https://www.epa.gov/ghgemissions/understanding-global-warming-potentials) helps compare the climate impact of different greenhouse gases. The [global warming](/content/climate/global-warming-definition-causes-and-effects/index.html) potential measures how much energy the emission of one ton of a gas will absorb, compared to the emission of one ton of carbon dioxide (CO2) over a given period, usually 100 years.

The higher the global warming potential, 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.

| **Greenhouse gas**       | **Global warming potential** |
|--------------------------|-----------------------------|
| Carbon dioxide           | 1                           |
| Methane                  | 27-30                       |
| Nitrous oxide            | 273                         |

_Credit: US EPA_

## Examples of Greenhouse Gases

Since the beginning of the [Industrial Revolution](https://www.britannica.com/event/Industrial-Revolution), humans have released more greenhouse gases into Earth’s atmosphere than needed to maintain a healthy greenhouse effect. These increased greenhouse gases come from manufacturing, transportation, and agricultural practices.

### **Carbon dioxide**

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 respiration but has risen to harmful levels in the atmosphere primarily due to burning fossil fuels. The Scripps Institution of Oceanography and the National Oceanic and Atmospheric Administration have recorded CO2 levels in the atmosphere at the [Mauna Loa Observatory in Hawaii since 1958.](https://gml.noaa.gov/ccgg/trends/mlo.html) This increase can be traced to carbon emissions from human activities.

_Credit: NOAA_

### **Methane**

Methane (CH4) occurs naturally through decomposition. The increase in atmospheric methane over the past two centuries comes from human activities such as fossil fuel production and cattle farming. Unfortunately, methane is much more harmful than CO2; its global warming potential is about 27-30 times higher.

### **Nitrous oxide**

Nitrous oxide (N2O) has recently spiked in the atmosphere due to agriculture and fossil fuel combustion. While it makes up only 6% of greenhouse gases, it has a global warming potential 273 times higher than CO2.

### **Fluorinated gases**

Fluorinated gases are greenhouse gases created exclusively by human activities. While these gases account for only around 2% of the total greenhouse gas emissions, they are thousands of times stronger than CO2.

## 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 only stays in the atmosphere for a couple of days before it returns to the earth in the form of precipitation.

High concentrations of ozone in the lower atmosphere can become a health hazard, while ozone in the Ozone Layer blocks harmful UV rays from the sun.

## How Do Greenhouse Gases Contribute to Climate Change?

Climate change occurs when the proportion of greenhouse gases in the atmosphere is unbalanced. Human activity — particularly fossil fuel use — is the leading cause of increased levels of greenhouse gases.

## Reducing Greenhouse Gases

Tackling climate change and reducing greenhouse gas emissions requires action from governments and individuals. Individuals can electrify their homes and shift diets away from meat toward plants. Additionally, installing solar panels can significantly reduce greenhouse gas emissions.

## Frequently Asked Questions

**What are major greenhouse gases?**

Carbon dioxide, methane, nitrous oxide, and fluorinated gases are some of the most important greenhouse gases for their role in climate change.

**Why are greenhouse gases a problem?**

Greenhouse gases trap heat in the atmosphere, leading to disruptions in weather patterns and contributing to global climate change.

**How do we reduce greenhouse gases?**

To reduce greenhouse gases, we need to shift from fossil fuels to cleaner forms of energy, like wind and solar power.