Not at all, at least not for humans. About this period, oxygen levels were probably around 4-5 percent, so we'd be nowhere near the 21 percent we're used to inhaling. The air would have mostly comprised nitrogen and greenhouse gases. Again, you'd most likely suffocate if you didn't have a breathing device.
Carboniferous air is a common theme in fossil fuels. Before we burned all the forests, they supplied us with lots of carbon dioxide that now forms part of our atmosphere. That's why there are trees on Earth today: because their predecessors weren't killed by lack of oxygen.
Now, plants still use carbon dioxide during photosynthesis, but it's the green plants that fix the gas and make more organic material out of it that get turned into soil when they die. So actually, we can breathe carboniferous air!
This article was written by Sarah Parcak, PhD candidate at George Mason University. She is currently writing a book about how fossils are used as time markers by scientists to understand changes in the environment through time.
The atmospheric concentration of oxygen is 21%, while the minimum necessary for humans is around 17%, therefore only roughly 1/4 of the atmosphere would have to be respired before the concentration could no longer support people. Global warming caused by higher CO2 levels would be a complicated issue. The amount of carbon dioxide that can be stored in the ocean is very limited, so there would be less space for other gases such as O2 or N2 for example. However, since CO2 is a gas that allows plants to grow more efficiently, removing it from the atmosphere may not be as disastrous for humanity as one might think.
The former has approximately 21% oxygen and less than 1% carbon dioxide. Once the air enters our lungs, gaseous exchange takes place. The air that we exhale contains about 4% carbon dioxide and 18% oxygen. Therefore, although the oxygen content is lower in expired air, it can still work to revive a person.
The latter is composed of water vapor (75%), nitrogen (20%) and other gases (5%). Exhaled air is actually the only source of breathable air for animals on land. Without it, they would die within minutes. This is because they cannot get rid of the carbon dioxide that builds up inside their bodies.
For humans to survive, they need oxygen and they need it fast. Our cells use oxygen to burn food with energy cells cannot live without oxygen. So as we breathe in oxygen, we are also breathing out carbon dioxide. This helps us release built-up energy stores as heat during physical activity or maintain body temperature at a constant level when we are not moving.
Without this gas exchange taking place, our blood would become saturated with carbon dioxide and we would asphyxiate. This would be similar to being stuck in a car with the windows shut - there would be no way to get fresh air in or waste gas out.
Exhaled air is therefore important for life because it allows us to remove carbon dioxide from our bodies while getting enough oxygen to stay alive.
No, not at all. Humans indeed exhale over three billion tons of carbon dioxide every year, but the carbon we exhale is the same carbon that the plants we consume "inhaled" from the atmosphere. This process is called "respiration" and it's how organisms produce energy for their lives.
When we die, our bodies begin to decompose quickly in hot climates or more slowly in cold climates. The carbon in our bones and teeth returns to the atmosphere through respiration by bacteria, while the carbon in our flesh returns to the atmosphere through decay. Over time, humanity as a whole adds its share to the global CO2 pool.
The amount of carbon dioxide we add to the atmosphere each year is far greater than what can be explained by human activity alone. An additional source is the carbon dioxide stored in forests, grasslands, and other vegetation grown for fuel or food. When these lands are cleared for agriculture or industry, they no longer take up carbon dioxide and so become sources of emissions instead. Removing carbon dioxide from the air is difficult because it requires direct exposure to the sun's light without any clouds or water present. Carbon dioxide molecules are colorless and odorless, which makes them hard to track as they move around the planet.