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Monday, June 23, 2014

The Gaseous Form of Manure

During the recent Senate hearing on climate change, Republicans once again trotted out one of their stupidest talking points: the notion that carbon dioxide is not a pollutant.
"I would say CO2 is a different kettle of fish," said [Senator Jeff] Sessions [(R-Ala)]. "It's plant food. It's not a pollutant in any normal definition."
Cow manure is also plant food. But you don't want it flowing freely through the streets or tainting your drinking water. 

Carbon dioxide is lung excrement.  It is a waste product of all animal life as well as the combustion of fossil fuels.

In other words, all that hot air Senator Sessions is spewing about climate change is almost literally the gaseous form of bullshit.

We can withstand carbon dioxide in small quantities, but it is deadly at higher concentrations. At 100,000 ppm (10%) it is deadly. Carbon dioxide poisoning -- CO2 retention -- is the direct cause of death by suffocation. It kills submariners and divers whose equipment fails.

If you put a plastic bag over your head the carbon dioxide pollution your lungs produce will kill you in short order. It's really that simple.

When people commit suicide in their automobiles or die accidentally from faulty venting of natural gas or propane heaters, the carbon monoxide (CO) from incomplete combustion kills them first (because CO binds to hemoglobin). But the carbon dioxide would also get the job done; it just takes a little longer.

Finally, plants need to respire oxygen in the absence of sunlight to drive their life processes, just like we do, and at that time they exhale carbon dioxide, just like we do. That means plants -- just like humans -- will die if the concentration of CO2 gets too high.

Carbon dioxide is therefore the very definition of a pollutant, though like many pollutants it is harmless in sufficiently small quantities. And since even oxygen is toxic at sufficiently high concentrations, Sessions' notions about "plant food" are idiotic from the get-go: it's all about proper concentrations.

Burning so much oil, gas and coal puts CO2 into the atmosphere far faster than plants and other natural processes can possibly remove it. That excess CO2 has been building now for 150 years, and it's heating the earth by entrapping the sun's warmth on the surface, instead of radiating that heat back into space in the infrared.

The earth is packed with life because it is has balanced systems, like the carbon cycle and the water cycle. Humans are knocking those cycles out of kilter on a massive scale: there are seven billion of us now.

We have doubled the amount of CO2 in the atmosphere over the course of several decades by burning gigatons of oil, gas and coal that had been buried over a billion years. At the same time we've deforested millions of square miles of forests that can no longer cleanse that "plant food" from the atmosphere because we're burning those all down too.

So, let me summarize in a folksy way that Mr. Sessions will understand: if you put too much manure on your petunias you'll kill them. And if we put too much CO2 into the atmosphere we'll kill the plants -- and ourselves.

3 comments:

GuardDuck said...

We can withstand carbon dioxide in small quantities, but it is deadly at higher concentrations. At 100,000 ppm (10%) it is deadly.

Well lucky for us the current level of CO2 in the atmosphere is 402 ppm (0.0402%).

Since that's about twenty-five times less than a deadly concentration we could probably be pretty accurate to continue to call it a plant food rather than using misleading vividness to appeal to fear as you have.


0.0402%

Larry said...

Lucky for plants, too, that they have a completely different mechanism for dealing with gases, as even the midly curious might suspect given that they don't have lungs. The current levels of CO2 may be high relative to the historic lows seen since the commencement of the ice ages 2.5 Myrs ago, but at quite low compared to previous levels. Also, at current concentrations, higher CO2 means that plants can get enough CO2 without leaving as moany stomata open for longer periods, which increases water loss. Higher CO2 means higher drought resistance, as well as better plant growth (up to a point, a point we are nowhere near reaching even under the most catastrophic predictions).

GuardDuck said...

Sorry, misplaced a decimal.


It's 250 times less than a deadly concentration, not 25.