What Are Greenhouse Gases?

Greenhouse gases which consist of Carbon dioxide, methane, nitrous oxide, fluorinated gases, and water vapor, are atmospheric gases that contribute to the greenhouse effect

The greenhouse gases play a vital role in maintaining Earth's habitability by keeping the planet warm enough to avoid entering a permanent ice age. The gases are emitted by natural processes (such as animal and plant decay) and human activities (including deforestation, burning fossil fuels, raising livestock, and producing cement).

Greenhouse gases are often associated with increasing average temperatures worldwide, and emissions vary by region.

Five Major Greenhouse Gases

There are five most common greenhouse gases: carbon dioxide, methane, nitrous oxide, fluorinated gases, and water vapor. Hereunder are also the effects that these gases produce.


Carbon dioxide (CO2)

Carbon dioxide is the biggest greenhouse gas contributor.

It is primarily produced by fossil fuel combustion, making it a key target of climate policy agreements.

Since the industrial revolution, carbon dioxide concentrations have increased by about 50%, mainly from fossil fuel emissions and partly from net land-use change emissions.

Methane (CH4)

Methane is the second greenhouse gas, and it is responsible for about 30% of Earth's greenhouse effect.

Its concentration in the atmosphere has gone up by 150% since 1750, and it mainly results from cattle breeding, rice cultivation, landfills, and leaks from natural gas systems.

Nitrous Oxide (N2O)

Nitrous oxide is released mainly by soil cultivation practices, wild plowing, fertilizing with manure, and applying nitrogen-containing chemicals.

It also contributes to the greenhouse effect, equivalent to approximately 6% of carbon dioxide emissions.

Fluorinated Gases

These greenhouse gasses are produced by the chemical industry, aluminum and magnesium production, the semiconductor industry, and electric power generation.

They only contribute a minimal amount to the greenhouse effect, but high concentrations of fluorinated gases can cause ozone depletion.

Water Vapor (H2O)

The greenhouse effect of water vapor is the most variable, with a short lifetime and a tendency to increase at high concentrations.

It can be counteracted by greenhouse gases and contributes to the greenhouse effect as it absorbs some long-wave radiation from Earth's surface. 

Greenhouse Gas Emissions by Source

There are several sources of greenhouse gases, such as:

Electricity and Heat Production

Greenhouse gas emissions are attributed to electrical power production. Gases are released when burning coal, oil, natural gas, or other fossil fuels.

The heat produced drives steam turbines that generate electricity.

Agriculture and Land-Use Changes

Emissions from greenhouse gases are also attributed to agriculture, forestry, and other land-use changes (LUCs).

Greenhouse gases are released when natural forests are cleared for agricultural purposes, the burning of biomass, such as trees and crop waste, and the decay of organic matter in the soil.


Industry processes and product use (IPPU) contribute to greenhouse gas emissions.

During the refining and burning of fossil fuels, such as gasoline (petroleum) and coal, manufacturing cement, producing chemicals and metals, and from landfills, greenhouse gases are released.


Greenhouse gases are released by gasoline-powered vehicles, diesel buses and trains, airplanes, ships, heavy trucks, and construction equipment.


Fuel combustion for heating and cooling homes, businesses, schools, and other buildings releases greenhouse gases.

Other Sources

Greenhouse gases that do not fall into the previous five greenhouse gas emissions categories are attributed to other sources.

Reducing Greenhouse Gas Emissions

Greenhouse gas emissions have been the subject of controversies and issues because of the threats they pose. The following are ways to reduce these emissions.


Use Less Energy

To reduce greenhouse gases, conserve energy whenever possible. For example, you can go for a walk, bike, or take public transportation when heading to work, school and errands.

Use rechargeable batteries and avoid using disposable batteries and paper products. Switch to ENERGY STAR-labeled appliances and lighting wherever possible.

Generate Electricity Without Emissions

Generating electricity without the release of carbon dioxide can help lessen the emission of greenhouse gases.

It can also be reduced by switching from the use of fossil fuels to clean energy sources, such as solar, wind, or hydropower.

Shrink the Footprint of Food

Greenhouse gas emissions can be reduced by wasting less food and making better choices when shopping and preparing food.

It can also be reduced by purchasing organic, local, or seasonal foods that have not been transported long distances and cutting meat consumption.

Travel Without Greenhouse Gas

Avoid unnecessary trips and take alternative modes of transportation whenever possible. Contributing to the release of greenhouse gases through trips can be reduced by avoiding car travel and using public transport, walking, or biking whenever possible.

Furthermore, taking short trips instead of long road trips, telecommuting, traveling during low-emission seasons (cooler months), consolidating errands into one day per week, combining trips, carpooling, and sharing rides are alternatives.

Reduce Emissions From Industry

Reducing greenhouse gas emissions is possible by using recycled materials instead of new ones. Moreover, it can also be reduced or avoided entirely by changing product packaging to use less material or switching from disposable containers to reusable ones.

Additionally, using greener materials in manufacturing, incorporating recycled material into products or production processes, recycling goods, and reducing energy use should be observed.

Take Carbon Dioxide Out of the Air

Greenhouse gas emissions can be reduced or eliminated by removing greenhouse gases already in the atmosphere.

Planting new trees, restoring native forests, using green infrastructure to minimize energy use, developing new products with fewer greenhouse gas emissions, and incorporating climate-smart practices into the design of infrastructure projects can also help eliminate these gases.

Key Takeaways

Greenhouse gases are naturally occurring and human-made. They play a critical role in maintaining Earth's climate.

Greenhouse gases from natural sources are not harmful, but greenhouse gases from human activities, such as burning fossil fuels, deforestation, livestock farming, and landfills, are detrimental to the environment.

Learn more about sustainable investing to understand how you as an individual can invest for retirement while investing in companies solving climate change.


1. What are greenhouse gases?

Greenhouse gases absorb heat in the atmosphere and contribute to the greenhouse effect.

2. What is the greenhouse effect?

It is a process by which the gases retain heat in the atmosphere rather than allowing it to escape into space.

3. What are examples of greenhouse gases?

The most common examples of greenhouse gases include carbon dioxide, methane, nitrous oxide, fluorinated gases, and water vapor.

4. What are the impacts of greenhouse gases?

Greenhouse gases can cause the greenhouse effect, which leads to increased greenhouse gas emissions, contributes to climate change, and results in extreme weather events. 

5. How are greenhouse gases emitted?

Gases are emitted by human activities, including burning fossil fuels, deforestation, and livestock farming. Greenhouse gases may also be emitted naturally from processes within the Earth's crust, oceans, natural vegetation, and other sources.

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