Misconceptions about CO₂

Injection Wells and Sustainable Energy Systems Carbon Capture Utilization and Storage Technology Misconceptions about CO₂

Although CO₂ and CO₂ emissions are widely discussed topics in the public sphere, many people lack a basic understanding of the science behind this gas. Because of CO₂‘s role in climate change, people have a tendency to categorize CO₂ as a “bad” gas. Some assume that it is harmful or unnatural at any concentration, or that it presents excessive health and safety hazards when at ground level. In short, they are wary of CO₂ because they don’t understand it—but we can help by educating them. Below are a few common concerns the public may have about CO₂, followed by facts related to these concerns.

Is CO₂ Hazardous to Breathe?

Just like water, CO₂ plays an integral role in maintaining human life, but too much of it can be a bad thing. But how much is too much, and how likely is the average person to encounter it? The short answer is, extremely unlikely, but let’s look at the science.¹

The biological trigger that makes us instinctively take a breath is actually the level of CO₂ in our blood, not the level of oxygen. Increased CO₂ levels make our blood slightly more acidic, and the low pH stimulates receptors in our brain that make us take a breath. Thus, abnormally high concentrations of CO₂ in our blood makes us breathe faster and harder. Normally this is fine, since it flushes the CO₂ out of our system, but if the surrounding atmosphere has too much CO₂, we will keep hyperventilating until we run out of oxygen and lose consciousness. This is CO₂ poisoning, also known as hypercapnia.²

So how likely are we to encounter hazardous levels of CO₂? Well, the normal air we breathe contains about 400 parts per million, or 0.04% CO₂. A crowded indoor setting may contain twice that, still with no ill effects. CO₂ actually needs to reach a concentration of 1% for us to begin noticing the effects at all. At that concentration a person will start to feel drowsy. At 3%, they will have an elevated heart rate, reduced hearing, and more severe drowsiness. It actually takes an 8% concentration, 200 times higher than normal, for CO₂ to cause someone to lose consciousness. For perspective, let’s compare that to one of the most common causes of gas poisoning, carbon monoxide. Carbon monoxide can kill you at levels as low as 1,600 parts per million, or 0.16%! That’s 50 times more potent than hazardous CO₂ levels. These numbers allow us to understand that to be hazardous, CO₂ levels would have to be so elevated that they could only occur in the most extreme scenarios. They are not something that the average person needs to worry about.³

Can CO₂ Blow Up?

Considering CO₂‘s relationship with the production and use of combustible fossil fuels, this concerns seems reasonable. However, the truth is that carbon dioxide cannot burn or explode. In fact, CO₂ is compressed and stored in fire extinguishers for this exact reason!

CO₂ fire extinguishers are actually superior to ones that use chemical foam because they don’t leave residue, and are particularly good at putting out electrical fires.⁴

Does CO₂ Leak Naturally From the Earth?

Yes, CO₂ naturally leaks from the Earth all the time, and this occurrence is actually a boon for scientists studying CCUS! The most dramatic events that leak CO₂ into the atmosphere are volcanic eruptions, but there are many natural leaks that don’t always grab our attention.⁵

Have you ever drunk a bottle of Perrier? Then you’ve enjoyed a by-product of natural CO₂ leakage! The bubbles in Perrier are due to a naturally occurring CO₂ leak under a spring in Vergèze, Gard, France, where the carbonated water is bottled at the source.⁶ Naturally carbonated water occurs around the world, usually in springs or bodies of water that lie above subsurface magma formations.⁷

Another example of a natural CO₂ leak is the Crystal Geyser near Green River, Utah. While most geysers generate their eruptive upwards force from geothermal heat, Crystal Geyser is a rare cold geyser that generates force from pressurized subsurface CO₂.⁸

So, why would all these natural leaks help scientists who are trying to store CO₂ securely underground? Quite simply, the ecosystems around naturally occurring CO₂ leaks teach us what to look for at storage sites to detect leaks. Scientists have discovered species of plants that tend to thrive near CO₂ leaks, methods for detecting soil acidity with electromagnetism, and other tools for detecting leaks. Additionally, scientists pay close attention to the geological formations present near natural CO₂ leaks—they show where not to put a storage site, often called a sequestration site. Natural leakage reveals a substrata that is not well suited to capturing and storing gas. Sequestration sites are carefully chosen where the geological formations effectively capture and retain CO₂.⁹

Previous Topic

Back to Lesson

Next Topic

Misconceptions about CO₂

Is CO2 Hazardous to Breathe?

Can CO2 Blow Up?

Does CO2 Leak Naturally From the Earth?

Is CO₂ Hazardous to Breathe?

Can CO₂ Blow Up?

Does CO₂ Leak Naturally From the Earth?