Breathing and climate change

Source: Derzsi Elekes Andor

Does breathing contribute to climate change? With every breath we take, we breathe in oxygen and breathe out carbon dioxide. Carbon dioxide is a greenhouse gas. So are we contributing to climate change just by the act of breathing?

If someone knows a bit about biology, they might respond, “no, because new plants will replace the plants we have eaten, and the new plants will take up the carbon dioxide.” The actual answer is not some glib assurance that new plants will replace the old, but “it depends.” And when you spin out what precisely it depends on, it has very significant implications for how we address climate change.

Al Gore’s response is that “we are participating in a closed cycle. That is, the carbon we breathe out comes from the food we eat, whether directly from plants, which take it in via photosynthesis, or indirectly from meat. So we get carbon from plants, breathe it out, and they take it in again.” (From Gore’s latest book, An Inconvenient Sequel, based on the movie of the same title, p. 234.)

Gore almost gets it. Let’s start with that last reassurance: “we get carbon from plants, breathe it out, and they take it in again.” Oh, really? To be balanced, there must be a net addition of plant life to the planet for each additional human (or additional cow). Are we doing that, do you think? Human and livestock populations have each more than tripled just in the 20th century. Have we seen a corresponding increase in plant matter?

Each additional human on the planet increases the amount of CO2 breathed out. If this additional human goes vegan and dedicates their lives to reforestation, then the answer is yes — there will be plants there to take up that CO2. But if this additional human decides to raze the rainforest to make a few dollars, then no — the total amount of plant matter on the planet will stay the same or even decrease. Most of us, of course, fall in between these extremes. But if our economy contributes to increasing cows and devastating plant life on the planet (think: meat consumption, deforestation, overgrazing, soil erosion), then it has much the same effect.

Historically, humans have had a very significant negative effect on plant life. Vaclav Smil estimates that during the last two millennia, total plant phytomass on Earth has declined by 40% (and 17% just in the 20th century).

Yes, there is a cycle here, but it’s not a closed cycle. We have disrupted it by destroying the plant matter on the planet, and through dramatic increases in human and livestock populations. We are not reutilizing all the CO2 that we (and our livestock) are breathing out. The biomass of large animals is now over seven times what it was just 500 years ago. We have upset the balance of nature.

These are the kinds of considerations that led Robert Goodland and Jeff Anhang to conclude that livestock contribute 51% of all human-caused greenhouse gas emissions. There are some legitimate scientific questions here, and we can debate whether the figure for livestock really is 51%, and not 35% or 65% or some other figure. Exactly how much CO2 does each human (and each cow) breathe out? How many cattle are there in the world, in the first place? How accurate are Smil’s estimates of the decimation of plant life?

However, this is not primarily a scientific issue. It is a logical issue, and most people (including Gore) who minimize the impact of livestock on climate have failed to even consider the impact of livestock and human population on the biological carbon cycle. When you multiply our net impact on the biological carbon cycle by the millions and billions of people and livestock animals on the planet, it’s going to be very significant. It should really be the centerpiece of the climate change discussion, not just a side issue.

11 Replies to “Breathing and climate change”

  1. It’s a difficult issue. Saddens me however that we have to prove we need to get rid of animal agriculture — it’s a no brainer that it needs to go! My own scientific knowledge isn’t something to write home about, but when I read the so called consensus on this topic, I am puzzled by some of the conclusions as with one climate scientist saying it’s immoral to consider the impact of livestock over a twenty year period???

    1. To avoid just avoid continually saying the same thing over and over again, I try to come at a problem from different angles. Very few people (whether activists, scientists, or political leaders) take the time to actually read and think about things (“critical thinking”). Since Gore actually mentions breathing in his book, and because breathing actually DOES contribute to climate change in the world we currently live in, I thought that would be a good way to say something slightly different and add insight to the current discussions.

      1. I’m not objecting to your post, but the fact that we have to defend veganism when it’s obviously a great idea. As far as the short term, that 20 year period – what would we do with all the livestock? It’s good to consider the impact over 20 years but could we phase out rapidly enough to make a difference. This may be the problem Hayhoe and others others see that makes them think we need to beyond 30 years.

        1. I agree. It’s a constant struggle to come up with words “that have the right amount of letters, just the right sound” to make people see that veganism is a good idea. The natural lifespan of cattle is about 20 years, so an instantly (humane) vegan world would see them mostly gone after 20 years.

      1. I believe Gore recognizes that our environmental problems are systemic and that a serious solution will require a system change which will necessarily upend his private plane privileges. Hence he pretends not to get it and works for a controlled degradation of the planet in which he continues to have such privileges even as the human population is whittled away to “sustainable” levels. But in such a controlled degradation scenario, it is not clear what those “sustainable” levels are. If people are dying in large numbers, won’t the planet be inhospitable to most life anyway?

        One of Gore’s Climate Reality board members told me that the whole world won’t go vegan until the human population is down to 1 billion! But why not begin right now before degrading the planet’s life-support systems?

  2. Science is about recalculating based on new discoveries and shifting understanding. Goodland and Anhang’s report in Worldwatch was rejected by many (eager to reject) because “the IPCC does not allow breathing to be included in greenhouse gas accounting.” There has never been a situation where an intelligent-yet-unwise species has bred megafauna to make their contribution to the biomass so dominant, with the explicit intent to expand the production of both species indefinitely. If the ratio of animal to plant biomass must be constant then it’s a matter of “simple math” it’s an embarrassing blind spot for the big brains at the IPCC (who are meeting in Montreal tomorrow…).

    There have been many who dismiss the conspiracy implied in the documentary Cowspiracy to be an overdramatization — have environmental NGOs met in underground parking garages to do a blood oath not to do awareness campaigns about animal agriculture’s greenhouse gases? I suspect that there have been many such conversations with the agricultural funding partners. It doesn’t matter. Three years after Cowspiracy there are still no awareness campaigns (and encouraging members to reduce their meat consumption in a sidebar buried on your website is NOT a campaign). If the sworn protectors of our environment can’t nut-up and tell the people the inconvenient truth about their dinner, they should burn and cauterize their tongues from suggesting that we should park our cars and ride bikes. Don’t Americans LOVE their cars/meat too much? If politics choose your truths then perhaps they should be considered “non-governmental” organizations after all.

    1. Well climatology has been downplaying the impact of CC and how rapidly it could advance. James Lovelock has testified to this in his books. The rationalization is “we don’t want to traumatize people and make them unwilling to act against climate change.” My guess is they think attacking dietary preferences would be counterproductive. And then of course their own food choices would be in question.

      1. I think even the resistance at encouraging a reduction of meat has been so slow in coming because they know full well how foolish it is to deem something harmful and then simply dial it down. The problem becomes when they cry “Fire!” (or in this case “Warming!”) the crisis can never be more serious than it’s solution. Climate change is bad…but we’re not going to change our way of life — it’s not THAT bad.” Unless it is. We should be mobilizing like a war effort, but instead we’re playing political footsie with the industries that willfully distract, delay and misinform. And to borrow from a call to arms, when the call went out to stop the Nazi regime, did they worry that people might get overwhelmed, or unwilling to act? You tell it like it is, and then mobilize with those who are ready to get to work.

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