What’s “a far more deadly gas” than the Sarin that Syrian President Bashar al Assad used to kill his own citizens—prompting President Trump to respond with a missile attack?

Carbon dioxide.

Or so says The Nation. According to “The Other Poison Gas Killing Syrians: Carbon Dioxide Emissions,” by University of Michigan Professor of History Juan Cole, “If Trump and his cronies really cared about children killed by noxious gases, they wouldn’t be trying to spew ever more CO2 into the atmosphere.”

We could laugh at the ignorance of the author, the fact checkers (if any), and the editors. Or we could rage at their dishonesty. Or we could cry at the ignorance of trusting but deceived readers. Maybe we should do all three.

Time for an elementary lesson in toxicology.

A lethal dose of Sarin is about one-half milligram. The average person exhales over 1 million times as much CO2 per day—about 1.04 kilograms.

If CO2 is “far more deadly” than Sarin, the human race should have perished when the first human took the first breath.

Just a little more about CO2’s toxicity—or rather, lack thereof.

Occupational exposure standards for CO2 are 0.5% (5,000 ppm) average through a 40-hour work week and 3% (30,000 ppm) for short-term exposure.

But those standards are overcautious. The National Research Council reports that “Data collected on nine nuclear-powered ballistic missile submarines indicate an average CO2 concentration of 3,500 ppm [0.35%] with a range of 0–10,600 ppm [0–1.06%], and data collected on 10 nuclear-powered attack submarines indicate an average CO2 concentration of 4,100 ppm [0.41%] with a range of 300–11,300 ppm [0.03–1.1%].” And we trust those submariners with control of nuclear ICBMs.

The breath we exhale contains about 40,000–53,000 ppm (4–5.3%) CO2.

Exposure to CO2 only becomes dangerous to life at about 35%, i.e., 350,000 parts per million—nearly 875 times the current atmospheric concentration.

Global average open-air CO2 concentration is about 407 parts per million (ppm) (0.04%).

So open-air CO2 concentration would have to be twelve-and-a-half times what it is today to reach the 40-hour work week standard; 74 times to reach the short-term exposure standard; and nearly 875 times to reach the life-threatening level.

Rising at about 3 ppm per year, it will take 1,531 years to reach the work-week standard, 9,864 to reach the short-term standard; and 13,198 to reach the life-threatening level.

That’s sufficient to expose Professor Cole and The Nation’s gross errors. It should warn us not to trust Cole’s central claims: human-induced climate change caused the “severest drought in recorded modern Syrian history in 2007–10,” which “made its contribution” to the Syrian civil war, which killed 400,000 people, left 23 million homeless, and made 4 million refugees.

The problem is that the Syrian drought was caused primarily by non-climatic factors.

The Fertile Crescent, which includes Syria, experienced about a 7% decline in winter rainfall since 1930, most before 1980. That leaves only about 3% of the decline during allegedly man-made warming, post-1980. Average annual surface temperature rose by about 0.5 C˚ since 1930, again about half before 1980. Those are not enough to explain the drought or the conflict over water.

So what did cause them?

From 1930 to 2010, Syria’s population multiplied 11 times, and its industrial and agricultural water use multiplied even more. That meant greatly multiplied water consumption, and hence shortages, regardless of temperature or rainfall.

“Drought” designates not low rainfall but water shortage—which can be caused by decreased rainfall, increased consumption, or accelerated runoff.

Did higher temperature and lower rainfall contribute? Perhaps. But the U.N. Intergovernmental Panel on Climate Change (IPCC) concluded in its 2012 report on extreme weather that it was impossible to demonstrate a connection between global warming and increasing frequency or severity of extreme weather events, including droughts.

Even if global warming contributed somewhat to the rise in temperature and decline in rainfall, that doesn’t mean human activity drove it. IPCC’s computer models simulate warming from rising atmospheric CO2 at double the observed rate, and recent research has found that most, maybe all, of the warming was driven by the El Niño-Southern Oscillation coupled with changes in solar output and the 1977 “Pacific Shift,” not by CO2.

So, at most, human activity contributed only a small fraction of the global warming, therefore only a fraction of the rise in temperature and decline in rainfall in the Fertile Crescent, therefore only a fraction of a fraction of the drought, and therefore only a fraction of a fraction of a fraction of the conflict over water.

Even the conflict over water pales into insignificance compared with religious and political conflicts as causes of Syria’s civil war, the rise of ISIS, and the consequent refugee crisis.

This isn’t even to mention the benefits of increased CO2, but they are many.

Plants must have it for photosynthesis. Every doubling of it causes an average 35% increase in plant growth efficiency. With more CO2, plants grow better in warmer and cooler weather and in wetter and drier soil, make better use of soil nutrients, and resist diseases and pests better. Consequently, they expand their range and the range of all insects and animals, which depend on them, greening the earth and reducing risks of species extinction.

They also yield more fruit. The result is more food for everything that, directly or indirectly, eats plants. And the poor benefit the most because rising CO2 makes food more affordable.

Professor Cole’s claim that CO2, because it contributes to global warming, is “far more deadly” than Sarin gas is precisely opposite the truth. It is both ludicrous and vicious.

Originally published on Patriot Post.

Updated 5/5/17, 11/3/17.