Again: Why do we worry about global warming? It ain’t the climate, it’s the people

This is almost entirely an encore post, repeated for the benefit of the millions who missed it the first time who make fools of themselves when they argue we don’t need to save trees.  It’s not about trees.

Kids hiking in a forest. These are the humans environmentalists worry about, these four, and a few billion like them.  Photo from American Forests.

Kids hiking in a forest. These are the humans environmentalists worry about, these four, and a few billion like them. Photo from American Forests.

Alun Salt gave great advice about not bothering to engage idiots, pigs, denialists or trolls (here, among other places).  He said I should avoid lengthy answers to blogs that have little audience.

This is probably one of those occasions.

But in a running attempt to stimulate serious thought at a denialist blog, I got a question that has been rather common, and a question which indicates the deep serious misunderstanding denialists and even some well-meaning, overly-skeptical sensible people have:

Why worry about  climate change, since the climate is changing all the time?  Especially, why are people like Al Gore urging that we stop climate change, when CO2 has no great direct effect on human health?  Shouldn’t environmentalists be cheering climate change on, since it’s a “natural process?”

The answer is lost on the other blog, as Mr. Salt predicted it would be.  But since I’ve gotten some version of the question repeatedly in the last month, I may as well repeat the answer here, for the record.

The short answer to why we worry about climate change is that, as with almost all environmental protection, we are worried first about the quality of life of humans, and ultimately about the ability of human life to survive at all.

Here’s the question put to me there:

Ed I’m a little confused. I thought we were talking about the effect of co2 on the climate not the effect of co2 on human health. Co2 is not a toxic gas and would have no effect on human health. The fact that humans weren’t around when co2 was 10-20 times higher has absolutely nothing to do with its effect on climate.
Ed there was no runaway greenhouse effect [link added here] or climate catastrophe. The planet was fine during the phanerazoic. There is actually a lack of co2 in the atmopshere comapred to that time.

Here’s my answer, with a few more links than their format would allow:

No, you’re not a little confused.  You’re a lot confused, greatly misinformed, and not thinking hard.

We worry about CO2’s effects on climate only because we worry about the future of humanity.  Many of us who have children and wish them the same blessings of having children and grandchildren, have thought through the truth of the matter that we don’t possess and rule the Earth for ourselves, but instead act only as stewards for future generations.

No Earth, no humans; but at the same time, no habitable Earth, no humans.  In the long run, Earth doesn’t care.  It’ll do fine — without humans.

We can’t damage the planet.  We can only damage its habitability for humans.

I don’t know what sort of dystopian Randian future you and other Do Nothings hope for, but it’s a future contrary to human life, American values, and all known religions.

We’re talking about the future of humans.  I tell “skeptics,” “If you don’t care, butt out.  You’ll be dead in the short run anyway, but that’s no reason to stand in the way of action not to ensure a livable planet for our grandchildren.”

You also fail to understand chemistry, pollution, and how the world works.  CO2 is indeed a toxic gas.  For about a century now we’ve had indoor air standards that require air circulation to keep CO2 down below concentrations of about 500 5000 ppm [see comments], because at that level it starts to have dramatic effects on humans working.  It clouds their thinking and causes drowsiness.  CO2 is a conundrum, in that it is also necessary to trigger mammalian breathing.  If CO2 drops too low, we don’t take in enough oxygen and may pass out.  Too much oxygen in place of CO2 is a problem in that regard.  A substance can be both essential and a  pollutant, at the same time. (This has vexed food safety experts for years, especially after the 1958 Delaney Clause; substances we know to be essential nutrients can be carcinogenic, in the same concentrations, or in the same concentrations with a slight twist in chemical formula — how do we regulate that stuff?)

English: Main symptoms of carbon dioxide toxic...

Main symptoms of carbon dioxide toxicity (See Wikipedia:Carbon_dioxide#Toxicity). References: Toxicity of Carbon Dioxide Gas Exposure, CO2 Poisoning Symptoms, Carbon Dioxide Exposure Limits, and Links to Toxic Gas Testing Procedures By Daniel Friedman – InspectAPedia Davidson, Clive. 7 February 2003. “Marine Notice: Carbon Dioxide: Health Hazard”. Australian Maritime Safety Authority. Model: Mikael Häggström. To discuss image, please see Template talk:Häggström diagrams (Photo credit: Wikipedia)

CO2 is toxic in much greater proportions — it was a CO2 cloud that killed thousands in Cameroon 30 years ago or so, if you know history.

Clearly you did not know that we’ve regulated indoor CO2 for decades.  Clearly you haven’t looked at the medical journals‘ discussion on CO2 — and I’ll wager you’d forgotten the Cameroon incident, if you ever knew about it.

CO2 is a toxic gas (the dose is the poison); CO2 has dramatic effects on human health — too little and we die, too much and we die.

The fact that humans were not around when CO2 was much higher is exactly the point.  That was presented here, as it is in most venues, as support for a claim that we don’t need to worry about CO2 pollution.  Well, that’s right — if we don’t care about a habitable Earth.  But when CO2 was higher, life for humans was impossible.

I think it’s reckless to run an experiment on what would happen with higher CO2 levels, using the entire planet as a testing place, and testing the hypotheses on just how much CO2 will kill us all off, and how.

How about a control group, at least?

In the past, massive CO2 created massive greenhouse effects that would devastate us today — not as a toxic gas, but as a result of the warming that greenhouse gases do.

Let us understand the physical conundrum of CO2 here:  Without the greenhouse effect from the human-historic levels of CO2, this would be an ice planet.  Our lives today depend on the greenhouse effects of CO2.

Consequently, anyone who claims there is no greenhouse effect fails to understand physics, chemistry, biology and history.  (Heck, throw in geology, too.)  Life would be impossible but for the greenhouse effect.  Life is impossible without water, too, but you can’t live totally surrounded by water.

Can it be true that there can never be too much of a good effect, with regard to greenhouse gases?  Ancient Greek ideas of “all things in moderation” applies here.  We need a Goldilocks amount of CO2 in our atmosphere — not to much, not too little; not too hot, not too cold.

To the extent that higher CO2 levels didn’t produce a total runaway greenhouse effect, as some hypothesize exists on Venus, we know that was due to other feedbacks.  Early on, for example, CO2 began to be reduced by photosynthesizing life.  Animal life today would be impossible but for that occurrence.  Few if any modern chordates could breathe the very-low oxygen atmosphere of the early Earth, and live.  Those feedbacks and limiting situations do not exist today.

Greenhouse Effect

Greenhouse Effect. Wikipedia image

So now we face a double or triple whammy.  The reduction in CO2 in the air was accomplished through a couple billion years of carbon sequestration through plants.  In fact, a lot of carbon was sequestered in carbon-rich fossils, stuff we now call coal and oil.  Oxygen replenishment was accomplished with massive forests, and healthy oceans, with a great deal of photosynthesis.  This created a rough CO2 equilibrium (with fluctuations, sure) that existed we know for at least the last 50,000 years, we’re pretty sure for the last 100,000 years (we know that from carbon-dating calibration exercises).

Today we have removed fully 30% of the forests that used to replenish oxygen and lock up a lot of CO2 (some estimates say 50% of the forests are gone); modern plant communities cannot pluck CO2 out fast enough.  Plus, we’re releasing a lot of that old, sequestered carbon in coal and oil — at rates unprecedented in human history.

Will more CO2 warm the planet?  We know from the fact that the planet is warm enough for life, that more CO2 will warm the planet more.  Anyone who says differently does not know physics and chemistry, nor history.

Is there anything that can stop that effect?  Sure — healthy, massive forests, and healthy oceans.  Reducing carbon emissions could help a lot, too.  But we’re committed for about a century.  CO2 in the atmosphere doesn’t fall to the ground like particulate pollution.  it drifts until it is incorporated into something else, either through photosynthesis or other chemical reactions.  It takes a mole of CO2 a couple of centuries to come out of the air.  We’re stuck with elevated and elevating CO2 regardless our actions, for a century or two, even if we are wildly successful in reining in emissions and creating sequestration paths.

What happens when CO2 levels get higher than 350 ppm?  History, physics and chemistry tells us glaciers will melt, rainfall patterns will alter dramatically, sea levels will rise, carbon will be absorbed by the seas in increasing amounts (causing acidification — simple chemistry).  [See the counter in the right column of this blog; by July 2013, CO2 temporarily climbed above 400 ppm in a spike, and rested dangerously close to 400 ppm constantly.]

It’s a very exciting experiment.  The entire human race is at stake. How much CO2 will it take to produce the effects that kill us all?  It’s likely that changing rainfall patterns and rising sea levels will produce wars over resources, long before CO2 itself starts being physically toxic.  That’s what the Pentagon’s big thinkers say.  That’s what the Chinese big thinkers say, which is why they are working to reduce emissions even without an enforceable treaty.

As experiments go, I think it’s immoral to use humans in experimentation without getting their consent, and without passing the entire experiment through the Institutional Review Board to make sure the experiment is useful, necessary, and done ethically.

Do you have those consent statements?  All seven billion of them?  Have you got approval from the research overseers of the institution?

If you don’t have permission to proceed with this progeny-killing experiment, why do you propose to proceed?  Many people believe that, if the courts on Earth don’t get us, a higher court will.

How will you plead wherever the call to justice is delivered?


5 Responses to Again: Why do we worry about global warming? It ain’t the climate, it’s the people

  1. Ed Darrell says:



  2. Ed Darrell says:

    What they said.


  3. Chris Ho-Stuart says:

    You’re welcome; a missing zero makes perfect sense.

    Apollo 13 is a classic example well known to the general public where the toxicity of CO2 was relevant. In that case, concentrations were well over 10,000 ppm, and approaching 20,000 ppm.

    As for atmospheric CO2 — the worst case scenarios could see atmospheric concentrations approaching 1000ppm by the end of this century; which would be madness, to be avoided at any cost. The climate impact in that case would be catastrophic; but direct physiological impact on humans would negligible. So you are correct that CO2 is toxic — but citing this as a problem associated with emission to the atmosphere is wrong, and a distraction from the actual problem we face.

    In this sense, your headline is misleading. The reason atmospheric CO2 matters really is climate — not direct human physiological effects. Another major reason for concern about rocketing atmospheric CO2 levels is that this leads to increase in CO2 dissolved in the ocean, with a consequent a change in the ocean pH. These things will indeed have drastic consequences on people — and the higher atmospheric CO2 goes, the worse the effects become. So we surely need to get industrial emission under control.

    So if a denialist tells you that CO2 is not toxic at the atmospheric levels in worst case emission scenarios — they are correct! The error of the denialist in this case is focusing on the wrong problem. The problem of atmospheric CO2 is the effect on climate.


  4. Ed Darrell says:

    You’re right; I think I left off a zero.

    My point remains, however: CO2 is not an inert, wholly harmless gas. Quite contrary to claims by the radical right wing, it is a toxic gas, and it can kill, and has.

    That is all subsidiary to its other characteristics, which make it a greenhouse gas.

    It’s a common trick of denialists, to pick a harm that is not one under study from a substance, and claim that the substance is not that harmful. For example, DDT was banned because it poisons entire ecosystems in the wild — it’s a serious threat to wildlife. DDT denialists and anti-environmentalists like to claim that DDT is not carcinogenic, and so should be “unbanned” in the U.S. DDT is still deadly to wildlife, however, still every bit as harmful to birds as it was 50 years ago. (Coincidentally, DDT has been implicated as a human carcinogen, since it was banned.)

    Climate denialists claim polar bears don’t need sea ice in the Arctic, since one of the bears was discovered to have made a 200 mile swim. The harm, however, is that the bears need ice to hunt; they can’t hunt in the water.

    That’s what’s going on with CO2. Do Nothingists claim CO2 is “natural” and that it is not acutely toxic to humans, and so shouldn’t be considered a pollutant.

    You can’t reason with people like that. You can’t reason a guy out of a position he didn’t get to by reason.

    Thanks for the correction.


  5. Chris Ho-Stuart says:

    Nice article Ed; excuse me this quibble:

    You say:
    [begin quote]
    For about a century now we’ve had indoor air standards that require air circulation to keep CO2 down below concentrations of about 500 ppm, because at that level it starts to have dramatic effects on humans working.
    [end quote]

    I think you have to be much more than 500 ppm before there’s a detectable effect on human working ability. The only reason I can see for using 500ppm as a bench mark is that it is a useful indicator for poor circulation in a building; not because CO2 is directly causing problems at that level.

    You cited the page from inspectapedia above (for info on regulation of levels indoor).

    According to that page, at a level of 10,000 ppm (20 times greater) and continuous exposure, *some* people might start to feel drowsy.

    According to their page on levels in buildings, a value of 600 to 800 ppm is “typical” for an occupied building. They also say: The US EPA warns that indoor ventilation is inadequate at CO2 levels of 1000ppm. They give more on regulatory limits at; 1000ppm is the lowest regulatory limit I can see there.

    I’m really dubious about 500ppm being a requirement; and I am positive that levels of any roughly comparable magnitude (like 1000ppm) are selected not to avoid CO2 toxicity, but as an indicator of poor circulation — which is to be avoided for its own right.

    You are perfectly correct that CO2 is toxic in sufficiently high concentrations. That is not a problem we face with atmospheric CO2 levels, even under any scenario of unchecked emissions of carbon pollution.

    The problem with atmospheric CO2 is the enhanced greenhouse effect. There’s no problem with CO2 toxicity, under any conceivable atmospheric levels we might reach in coming centuries.

    In the worst case scenarios, we face a hellish climate. Substantial regions would be come effectively uninhabitable for humans working outdoors. Disruptions and changes in climate patterns would see wholesale mismatch of agricultural infrastructure with local conditions. The consequences would be devastating — but toxicity isn’t a part of that equation.


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