What is Carbon Dioxide?

Looking up at tall trees

Written by TerraPass


Carbon dioxide (CO2) is nearly undetectable. However, this colorless, odorless gas that dissolves in water is always nearby. Every time you exhale, CO2 is released, and when fossil fuels are combusted, an even larger amount of this gas goes into the atmosphere. While CO2 is part of life—plants even need it to grow—too much of it can be a bad thing. Over the years, more and more CO2 has been released into the atmosphere, leading to measurable increases in things like global warming. [1] If you are concerned about what carbon dioxide is doing to the planet, then keep reading to learn more about what it is, where it comes from, and how to reduce it.

Why Is CO2 Important

CO2 sometimes gets a bad rap, but the reality is it is essential to life as we know it. For starters, this greenhouse gas affects the temperature of the planet by trapping heat in the atmosphere. Without it, the planet’s temperature would be freezing and not livable. CO2 is also critical to plant life. [2] Even our bodies need CO2 to function correctly. [3]

What Are the Benefits of CO2

CO2 plays a vital role on our planet and is critical to human and plant life. In fact, while increased CO2 contributes to global warming, it may also be helping increase global vegetation at the same time. Some studies have shown that CO2 increases photosynthesis to help plants grow better. [4]

What Are the Negative Effects of CO2

When it comes to CO2, you can have too much of a good thing. In fact, too much of this gas can have deadly consequences for humans in more ways than one. When people are exposed to large amounts of C02, carbon dioxide poisoning can occur, creating problems for your heart, brain, lungs, and extreme cases can even cause death. [5] Just like the human body, too much CO2 can also have disastrous effects on the environment, contributing to warming weather, melting ice caps, and overall climate change that is threatening everyday life on earth. [6]

Carbon Dioxide Emissions

CO2 emissions are a complex, global issue. Governments and organizations across the globe are working to identify the sources of CO2 emissions and come up with a plan to reduce them. While some solutions such as the Paris Climate Agreement, have shown potential to help curb the problem, growing CO2 emissions remain a concern to many.

What Causes Carbon Dioxide Emissions

There are many things both in nature and human-made that contribute to CO2 emissions around the world. Below is the break down of the main contributors and whether or not they come from nature or are influenced by human behavior. [7]

Natural CO2 Causes

  • Ocean-Atmosphere Exchange
  • Plant & Animal Respiration
  • Decomposition of Organic Material
  • Volcanic Activity & Eruptions
  • Weathering of Carbonate Rocks

Human-Made CO2 Causes

  • Fossil Fuel Use
  • Land Use
  • Industrial Processes

CO2 Emissions by Source

Humans are almost entirely responsible for a significant increase in carbon emissions over the last 150 years. The largest contributor to CO2 emissions in the United States is the burning of fossil fuels. Below is a break down of the main contributing factors to greenhouse gas emissions, according to the Environmental Protection Agency (EPA). [8]

  • Transportation (28.9 %)
  • Electricity production (27.5%)
  • Industry (22.2%)
  • Commercial and Residential (11.6 %)
  • Agriculture (9%)

What Are the Safe Levels of CO2

Earlier, we discussed how CO2 is needed in small doses, but once you have too much of it, things can become dangerous. So what are the safe levels of CO2? Well, it depends on the situation. For example, indoors, anything above 1,000 parts per million (ppm), people will start to notice the difference in air quality, and above 2,000 ppm, people will start experience moderate to severe health problems. Ideally, indoor air should have between 250 and 350 ppm, and carbon dioxide detectors are available, similar to carbon monoxide detectors. [9]

On a global scale, these numbers are also being watched closely. According to NOAA Climate.gov, the global average in 2018 for CO2 was just above 400 ppm. If you have been following climate change news over the years, then you may recognize the significance of this number. This measurement is the highest ever for the planet since measurements began. Many people worry these levels could also spell disaster for climate change. [10] To be safe, global CO2 should be at 350 ppm or less. [11]

Reducing CO2

While its true carbon dioxide emissions around the globe could continue to increase, there are some things normal everyday people can do to help limit their carbon footprint. Below are five ways you can start today to make a real difference for yourself and the environment. [12]

1. Reduce Your Energy Use

Most people’s homes are filled with appliances and electronics that are constantly requiring energy. You can limit your home’s energy requirements by upgrading to LED light bulbs, using energy-efficient appliances, and unplugging electronics when they are not in use. Taking these small steps will limit your energy uptake and reduce potential CO2 emissions from your local power plant.

2. Switch to Renewable Energy

Whenever possible, select renewable energy options for your home. While installing things like solar panels may not always be possible, you may have the option of choosing where your power comes from. Check with your energy supplier and ask if they offer plans that include energy from renewable sources. Opting out of any traditional fossil-fueled plants may help you reduce a lot of carbon every year.

3. Travel Mindfully

Transportation in the form of flights, ships, trucks, and other vehicles is one of the leading contributors to CO2 emissions in much of the world. That means if you are looking to reduce your carbon footprint, you will need to start to travel more mindfully. Look for opportunities to take public transportation, drive less, and support companies that strive to be green.

4. Calculate Your Carbon Footprint

You can’t manage what you don’t measure. That is why terrapass offers a free carbon footprint calculator for anyone to use. You can see what your real impact is, and start to make smart, green choices to reduce it.

5. Buy Carbon Offsets

There is another thing you can do to live a carbon-neutral life. Carbon offset offer an affordable way to help balance the carbon emission we all create from everyday living. When you purchase a carbon offset, that money goes towards supporting renewable energy projects, planting trees, and other carbon reduction efforts. At terrapass, we proudly offer third-party verified offsets to ensure the highest quality offsets possible for our customers. You can learn more by checking out our sustainable living offset plans for individuals.


  1. “Graphic: The Relentless Rise of Carbon Dioxide – Climate Change: Vital Signs of the Planet.” NASA, NASA, 12 June 2019, climate.nasa.gov/climate_resources/24/graphic-the-relentless-rise-of-carbon-dioxide/.
  2. “Carbon Dioxide.” Carbon Dioxide | UCAR Center for Science Education, scied.ucar.edu/carbon-dioxide.
  3. “About Good Breathing.” Lang, www.advancedbuteyko.com/about-good-breathing-10-reasons-why-we-need-co2.php.
  4. “CO2 Is Making Earth Greener-for Now – Climate Change: Vital Signs of the Planet.” NASA, NASA, 3 May 2016, climate.nasa.gov/news/2436/co2-is-making-earth-greenerfor-now/.
  5. Langford NJ. Carbon dioxide poisoning. Toxicol Rev. 2005;24(4):229-35. https://www.ncbi.nlm.nih.gov/pubmed/16499405
  6. “National Snow and Ice Data Center.” Glaciers and Climate Change | National Snow and Ice Data Center, nsidc.org/cryosphere/glaciers/questions/climate.html.
  7. “Main Sources of Carbon Dioxide Emissions.” What’s Your Impact, 8 July 2017, whatsyourimpact.org/greenhouse-gases/carbon-dioxide-emissions.
  8. “Sources of Greenhouse Gas Emissions.” EPA, Environmental Protection Agency, 13 Sept. 2019, www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions.
  9. BoninoApr, Steve. “Carbon Dioxide Detection and Indoor Air Quality Control.” Occupational Health & Safety, ohsonline.com/articles/2016/04/01/carbon-dioxide-detection-and-indoor-air-quality-control.aspx.
  10. “Climate Change: Atmospheric Carbon Dioxide: NOAA Climate.gov.” Climate Change: Atmospheric Carbon Dioxide | NOAA Climate.gov, 19 Sept. 2019, www.climate.gov/news-features/understanding-climate/climate-change-atmospheric-carbon-dioxide.
  11. “400.350.Org.” 400.350.Org, 400.350.org/.
  12. “Top 20 Ways to Reduce Your Carbon Footprint.” 20 Ways to Reduce Your Carbon Footprint, www.globalstewards.org/reduce-carbon-footprint.htm.

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