Understand greenhouse gas emissions vs. carbon emissions

What are greenhouse gas emissions?

Put simply, a greenhouse gas (GHG) is a type of vaporous matter -- or gas -- in a planet's atmosphere that traps heat. There are several greenhouse gas types. In the case of Earth, these include carbon dioxide, methane, nitrous oxide, fluorinated gases and water vapor.

Emissions are the release of such gases into the atmosphere.

So, greenhouse gas emissions are the release of greenhouse gases such as carbon dioxide and methane into Earth's layer meant to protect it from space.

What are carbon emissions?

In the simplest terms, carbon emissions are just a specific category -- carbon dioxide emissions -- of greenhouse gas emissions. Carbon emissions are sometimes referred to as carbon pollution.

Why do people confuse the terms?

The reason people might confuse terms such as greenhouse gas emissions, GHGs, carbon emissions, carbon dioxide and carbon pollution has to do with two main areas:

• Carbon as the main driver of rising greenhouse gas emissions.
• How most people best understand concepts around climate change.

Carbon emissions driving rising GHGs

Carbon emissions, which come primarily from burning fossil fuels, receive so much attention because they're the main driver of climate change and global warming. Because of that, carbon is often used as shorthand to mean greenhouse gas emissions.

Here is a cheat sheet for some common carbon-related terms:

• Carbon. The shortened way to refer to carbon dioxide.
• Carbon dioxide equivalent. A common unit to describe different greenhouse gases based on their global warming potential; also called CO2e.
• Carbon emissions. The discharge of carbon dioxide into the atmosphere.
• Carbon footprint. The total amount of greenhouse gases that an individual or organization generates.
• CO2. Scientific shorthand for the chemical compound carbon dioxide.

Confusion around climate change communication

People who become familiar with climate change terminology might forget to tailor their communication in a way their audience will best understand.

For example, although the terms greenhouse gas emissions, carbon emissions and carbon pollution all appear in association with climate change, people in the United States associate the terms carbon emissions and carbon pollution more with human and environmental harm, compared with the term greenhouse gas emissions, according to the 2023 study "Evaluating Terms Americans Use to Refer to 'Carbon Emissions,'" published in the journal Environmental Communication. People are also more likely to understand that fossil fuels create carbon pollution and emissions as compared with greenhouse gas emissions.

Studies like this suggest that language matters, and explaining sustainability issues in terms that a nonscientific public can understand is critical.

In brief: How GHGs and carbon emissions heat the planet

Greenhouse gases such as methane, nitrous oxide, fluorinated gases and carbon dioxide are increasing and responsible for global warming and climate change.

Here's how it works: Greenhouse gases trap heat in the atmosphere by absorbing and reemitting infrared radiation back toward Earth's surface, which then keeps the planet warmer than it would be otherwise. This is what's known as the greenhouse effect.

In an actual greenhouse, the sun's light is able to pass through the glass walls, enabling the plants within to absorb it. The plants and soil then emit some of the absorbed heat energy as infrared radiation, which the glass absorbs and emits back into the greenhouse. This helps the greenhouse retain heat and stay warmer than it otherwise would be.

Greenhouse gases such as methane and carbon work similarly. The sun's radiation passes through the atmosphere and is absorbed by Earth's surface. Some of that energy is emitted back into the atmosphere as infrared radiation. Some of the radiation passes back into space. But GHGs absorb some of the radiation and reflect it back to Earth again to heat the planet.

Ideally, greenhouse gases keep Earth's temperature balanced -- not too cold and not too warm.

The problem is that with the start of the Industrial Age, around the mid-1700s, people have increasingly mined, extracted and burned fossil fuels such as coal, oil and natural gas. These fossil fuels have increased and disrupted the level of greenhouse gases and, in turn, driven climate change.

The scientific community is virtually united in agreement that climate change is real, that humans have caused and continue to worsen it, and that decisive and major action needs to be taken across all stakeholders, according to the 2021 global research review "Greater Than 99% Consensus on Human Caused Climate Change in the Peer-Reviewed Scientific Literature," published in the journal Environmental Research Letters. The study examined a randomized assortment of 3,000 climate science-related papers published since 2012.

The Intergovernmental Panel on Climate Change, a United Nations global scientific body commonly referred to as the IPCC, calls for everyone to get involved in addressing climate change to secure a livable future.

Business and IT professionals, in particular, have a number of ways to get involved, including reducing the digital carbon footprint, creating a more sustainable office and implementing solid carbon accounting practices.

Diann Daniel is an executive editor overseeing a number of sites within Informa TechTarget's Enterprise Software and Services group, including Sustainability and ESG.

Jacob Roundy is a freelance writer and editor with more than a decade of experience in a variety of tech topics, such as data centers, business intelligence and sustainability.