At a glance - Does breathing contribute to CO2 buildup in the atmosphere?

On February 14, 2023 we announced our Rebuttal Update Project. This included an ask for feedback about the added "At a glance" section in the updated basic rebuttal versions. This weekly blog post series highlights this new section of one of the updated basic rebuttal versions and serves as a "bump" for our ask. This week features "Does breathing contribute to CO2 buildup in the atmosphere?". More will follow in the upcoming weeks. Please follow the Further Reading link at the bottom to read the full rebuttal and to join the discussion in the comment thread there.


At a glance

We, and almost all of our relatives in the animal kingdom, are aerobic. That means we all depend on this simplified equation in order to function:

glucose + oxygen → carbon dioxide + water + energy

We breathe in oxygen and that oxidises carbohydrates in our body's cells. That chemical reaction gives us the energy required to perform all the varied tasks we do, from blinking to running a marathon. The products of the process are carbon dioxide and water. While the air we breathe in contains just under 420 ppm CO2, what we breathe out contains 40,000-50,000 ppm CO2, a hundredfold increase due to the simplified equation above.

Because we are breathing constantly, this rapid gas-exchange with our surroundings is also constant and, while each of us live, is perpetual. We are part of the fast carbon cycle that involves the movements of carbon through the living world. Of course, the living world also includes plants. Plants take in carbon dioxide to react in the presence of sunlight with the water in their cells. That, in a nutshell, is photosynthesis, the process responsible for the plant-based carbohydrates we eat.

We are vastly outnumbered in terms of carbon biomass by the plant kingdom. Of the estimated nearly 500 billion tonnes of biomass carbon on Earth, the animals account for just 0.4% whilst the plants represent 90%. No wonder that the graphs of measured CO2 levels show an annual fluctuation, forming a symmetrical wobble. The wobble represents the Northern Hemisphere seasons because that's where most of Earth's land masses are found. In the growing season when the plants are busy photosynthesising, CO2 falls, only to rise again in the dormant season. The annual wobble is like the heartbeat of the planet, a regular rhythm along the rising slope that represents our emissions from fossil fuel burning.

Let's imagine a world without fossil fuel-burning. The annual wobble from the seasonal growth and dormancy of plants would be superimposed upon a near-flatline of CO2 levels over human lifetimes. Only occasional events, occurring over tens of thousands to many millions of years, would perturb that near-flatline. That's because there is a second, slow carbon cycle that operates over geological time-scales. In the geologic past, sudden changes in CO2 levels have occurred, primarily due to volcanism on a scale no human, living or dead, has ever witnessed. The fossil record tells us the outcome has never been good.

Fossil fuels are part of the slow carbon cycle. They represent one of several long-term geological reservoirs in which carbon gets locked away. But because we are digging or pumping fossil fuels from the ground and burning them, it is the slow carbon cycle that we are interfering with. No other species has ever intentionally interfered with the slow carbon cycle: this is a first on Planet Earth in its 4.5 billion year long existence. The person quoted in the myth box above is a geologist. He should know better.


Please use this form to provide feedback about this new "At a glance" section. Read a more technical version below or dig deeper via the tabs above!

Click for Further details

In case you'd like to explore more of our recently updated rebuttals, here are the links to all of them:

Myths with link to rebuttal Short URLs
Ice age predicted in the 1970s
It hasn't warmed since 1998
Antarctica is gaining ice
CRU emails suggest conspiracy
What evidence is there for the hockey stick
CO2 lags temperature
Climate's changed before
It's the sun
Temperature records are unreliable
The greenhouse effect and the 2nd law of thermodynamics
We're heading into an ice age
Positives and negatives of global warming
Global cooling - Is global warming still happening?
How reliable are climate models?
Can animals and plants adapt to global warming?
What's the link between cosmic rays and climate change?
Is Al Gore's An Inconvenient Truth accurate?
Are glaciers growing or retreating?
Ocean acidification: global warming's evil twin
The human fingerprint in global warming
Empirical evidence that humans are causing global warming
How do we know more CO2 is causing warming?
Explaining how the water vapor greenhouse effect works
The tricks employed by the flawed OISM Petition Project to cast doubt on the scientific consensus on climate change
Is extreme weather caused by global warming?
How substances in trace amounts can cause large effects
How much is sea level rising?
Is CO2 a pollutant?
Does cold weather disprove global warming?
Do volcanoes emit more CO2 than humans?
How do human CO2 emissions compare to natural CO2 emissions?
Climate scientists could make more money in other careers
How reliable are CO2 measurements?
Do high levels of CO2 in the past contradict the warming effect of CO2?
What is the net feedback of clouds?
Global warming vs climate change
Is Mars warming?
How the IPCC is more likely to underestimate the climate response
How sensitive is our climate?
Evidence for global warming
Has the greenhouse effect been falsified?
Does breathing contribute to CO2 buildup in the atmosphere?


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Posted by John Mason on Tuesday, 12 December, 2023

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