I really know nothing about global warming, but there’s such an interesting discussion going on in the comments to this post that I thought it deserved its own dedicated post. Just to kick things off, I’ll reprint Eyebrows McGee’s initial comment about it:
“Global Warming†is something of a misnomer, although a general warming trend is one of its effects. A better name might be “breakdown in the planet’s ability to exchange oxygen and carbon dioxide†due to loss of plant mass and burnt release of long-dead fixed-CO2 from organic matter (i.e. coal and oil) releasing unprecedented amounts of CO2 into the air at the same time as we have DRASTICALLY reduced the number of organisms available to convert it to oxygen.
If you know about plant respiration, it’s a relatively simple “math problem.†There is ONE type of organism capable of converting the earth’s sole source of external energy — the sun — into sugars, and those are the photosynthesizing plants. These same plants breathe in carbon dioxide and take up water from the soil (CO2 and H2O) and, using the sun’s energy to power the complex chemical reaction, convert the carbon dioxide and water into sugars (C6H12O11) and Oxygen (O2). (They also respire out — and clean in the process — an awful lot of our. My front-yard hackberry probably respires about 60 gallons of water per hour in the summer, cleaning it as it draws it up from the ground and uses impurities as mineral building blocks.)
Basically all energy on earth comes from the photosynthesis reaction. Animals eat plants for the sugars. Fossil fuels are “trapped†photosynthetic sugars (and the various more complex molecules that result from those reactions, or from what other organisms do with the sugars.)
If you have a little biodome with 2 trees photosynthesizing and two animals eating exactly the amount of fruit they produce and breathing exactly the amount of oxygen they create, and you kill one of those trees, CO2 in your biodome is going to skyrocket, inadequate food production will occur, and at least one of those animals is going to die. (Or they may both die, fighting for the limited resources. Or by degrading their remaining “habitat†tree until it can no longer support even one.)
If you have a giant earth biodome and you clear 1/3 of the planet’s photosynthetic material while simultaneously releasing massive quantities of STORED plant energy (fossil fuels) back into the atmosphere, you’re not only trying to support the same size (or in humanity’s case, ever-increasing) population of animals with ever-less available “air-exchangers†and “food,†but you’re now making the deficit worse by releasing stored energy the air-exchangers have to do MORE work to exchange.
There are a handful of species that produce food without photosynthesis (like fungi), but they’re pretty calorically useless to higher animals. (Mushrooms have hardly any calories.) If you want oxygen to breathe and energy to eat, you need photosynthetic plants. It’s a simple, quantifyable chemical reaction. If you decrease the “plant†side enough, one of two things will happen — animals (and their “works†— like modern fossil fuel consumption, say) will have to decrease proportionately, or organisms that do well in excess carbon dioxide will thrive and species that require current oxygen levels will die. You know which one we are.
Earth is essentially a closed system (barring the occasional asteroid, etc.). Resources are finite. Waste products can’t be “thrown away†because they have nowhere to GO. Closed system. The only outside “power source†we have is the sun, and photosynthetic plants are the only organisms that can make use of it to create food to support the rest of us.
(If you wanna really scare the crap out of yourself about “global warming†(and why modern methods of increasing crop yields are not long-term sustainable in our closed system), go read about the nitrogen imbalance. Making greener and better and higher-yield plants won’t help the problem if it “costs†more in energy to make the plants yield more calories than you get back out of them in calories.)
And of the 4 or 5 billion years Earth’s been hanging around, primitive organisms and later plants were spending an awful lot of time creating an atmosphere we could breathe and calories we can make use of!
Earth itself will recover from our depredations just fine. Organisms will doubtless evolve that can make use of our waste products. But WE can’t survive our current depredations and I’m personally fond of me.
Feel free to comment on any aspect of global warming you wish. I have one question for Eyebrows, though. For those of you who don’t know, Eyebrows McGee (aka Laura Petelle) is a lawyer but also has a theology degree. Thus, in light of her final comment, I’d be interested in hearing how her view of humankind’s demise via global warming meshes with her eschatology.