The Ecological Crisis & Its Solution (Part 2): More Climate Science for Skeptics

The Carbon Cycle & The Delicate Balance of the Planetary Ecosystem

Modern industrial society runs on fossil fuels: we burn natural gas and propane to heat our homes, burn coal to make electricity, and burn gasoline to run our automobiles. Fossil fuels are composed of organic material—plants and animals—that have decomposed and been put under pressure beneath the earth for millions of years. Crude oil, for instance, is what is left of ancient plankton. Contrary to popular belief, fossil fuels aren't liquefied dinosaur remains. We are literally burning ancient algae and swamp muck from dead bacteria. What we are burning is what remains of ancient carbon-based lifeforms. When we burn fossil fuels, we are taking carbon that has been buried beneath the earth in solid or liquid form for hundreds-of-millions of years and causing it to combust and be released into the atmosphere.

The Earth has a natural carbon cycle. Plants consume H²O (water) and CO₂ (carbon dioxide) and convert them into carbohydrates (sugars) and oxygen through photosynthesis. Technically, during photosynthesis all of the oxygen atoms from CO₂ go into carbohydrates, while the oxygen atoms released into the air by the process actually come from the breaking apart of H²O. So plants don't technically convert carbon dioxide into oxygen, but they do remove carbon dioxide from the air and replace it with oxygen. Animals consume carbohydrates and oxygen in order to survive. When we breath in oxygen, we breath out carbon dioxide. The carbon is cycling though the planetary ecosystem, switching forms as it goes. Ultimately, we find a delicate balance.

By taking carbon that has been trapped beneath the earth for 300 million years and releasing it into the atmosphere through combustion, we are throwing off the delicate balance. The carbon atoms contained in fossil fuels have not been part of the carbon cycle since at least 297.5 million years before humans arrived on this planet. By taking this carbon from beneath the earth and releasing it into the atmosphere through combustion, we are placing carbon into the carbon cycle that has not been part of the carbon cycle since long before the first mammals emerged upon the face of the Earth.

This may not seem like much of a problem, but allow me to point to a somewhat analogous problem. Imagine a farmer raises livestock. His livestock produces waste in the form of fecal matter, which he can use as manure to fertilize his crops. There is no problem with an increase in the amount of waste from animals, so long as the farmer can grow more crops in order to use up the extra manure. However, if the animal waste starts to exceed what can be effectively used as manure, it will start to poison the crops. Here is an article about how too much compost can poison you garden. Here is another article about how too much manure can damage crops. Over-application of manure to farmlands results in nitrates seeping into groundwater, creeks, and rivers. These nitrates can cause health problems in humans and can even cause miscarriages. Just the right amount of manure leads to greater crop yields, whereas too much manure can cause an ecological disaster. Likewise, the right amount of carbon dioxide is beneficial, but too much carbon dioxide can cause an environmental crisis.

The Problem of Global Warming & How We Know That Humans Caused It

Greenhouse gases trap heat on Earth. The experiment I talked about in Part 1 of this series—the one involving a jar of CO₂ and a heat lamp—demonstrates how greenhouse gases work. The jar represents the Earth, the lamp represents the Sun, and the CO₂ simply is a greenhouse gas. Greenhouse gases capture and emit heat. Just as our greenhouse gas captured energy from our lamp and retained it in the jar in the form of heat, so also do greenhouse gases in the atmosphere capture energy from the sun, retain it, and emit it as heat. This process is what is behind global warming. CO₂ is not the only greenhouse gas. There are other greenhouse gases too, like methane (CH₄), SO₂ (sulfur dioxide), CFCs (chlorofluorocarbons), and water vapor. Increases in the amount of many greenhouse gases in the atmosphere result from human activity. SO₂ and NO_X, for instance, are released into the atmosphere when we burn coal. You might be aware that CFCs were once contained in hairspray bottles and other aerosol cans and contributed to the creation of the hole in the ozone layer.

Scientists have established that the amounts of various greenhouse gases in the atmosphere are rising and that the Earth is heating up as a result. Climate science skeptics often ask, "Well, how do we know that the increase in greenhouse gases is the result of human activity?" Well, there are several ways to determine this. The simple answer is basic logic. If we analyze the chemical composition of emissions released from the combustion of fossil fuels, we can see that CO₂ and SO₂ are among the chemicals released. We know that the carbon in fossil fuels was trapped deep beneath the earth for millions of years, so the releasing of this carbon into the atmosphere logically has to mean that we are increasing the amount of carbon in the carbon cycle. We can deduce that combustion of fossil fuels must logically lead to an increase in CO₂ in the atmosphere since we are adding additional CO₂ on top of the CO₂ that is already naturally produced by the carbon cycle. The more complex and scientific way that we can tell that increased levels of greenhouse gases are caused by humans is by analyzing isotopes. Each element can come in various isotopes. The isotope refers to the number of neutrons within the atom. Every carbon atom has 6 protons. However, the number of neutrons may vary. Thus, carbon¹² has 6 protons and 6 neutrons, while carbon¹³ has 6 protons and 7 neutrons, and carbon¹⁴ has 6 protons and 8 neutrons. Plants contain more lower carbon isotopes like carbon¹² than higher carbon isotopes. This is how one article explains how analyzing isotopes reveals the source of CO₂ emissions:

"Another, quite independent way that we know that fossil fuel burning and land clearing specifically are responsible for the increase in CO₂ in the last 150 years is through the measurement of carbon isotopes. Isotopes are simply different atoms with the same chemical behavior (isotope means “same type”) but with different masses. Carbon is composed of three different isotopes, ¹⁴C, ¹³C and ¹²C. ¹²C is the most common. ¹³C is about 1% of the total. ¹⁴C accounts for only about 1 in 1 trillion carbon atoms.

"CO₂ produced from burning fossil fuels or burning forests has quite a different isotopic composition from CO₂ in the atmosphere. This is because plants have a preference for the lighter isotopes (¹²C vs. ¹³C); thus they have lower ¹³C/¹²C ratios. Since fossil fuels are ultimately derived from ancient plants, plants and fossil fuels all have roughly the same ¹³C/¹²C ratio – about 2% lower than that of the atmosphere. As CO₂ from these materials is released into, and mixes with, the atmosphere, the average ¹³C/¹²C ratio of the atmosphere decreases."(How do we know that recent CO2 increases are due to human activities?)

I know that I have already said this, but it is worth repeating for emphasis: Since we know that we are releasing CO₂, SO₂, and other greenhouses gases from fossil fuels into the atmosphere through combustion—and we know that the elements in these chemicals were previously trapped beneath the Earth's surface for hundreds-of-millions of years―, it would be absurd to think that we were not causing an increase in greenhouse gases. While the normal natural processes on our planet continue to break down and produce greenhouse gases at the same rate as usual, we are pumping tons of additional greenhouse gases into the atmosphere from a different source, a source deep beneath the surface of the Earth. It is as if we have cracked open Pandora's box and released all the evils upon the Earth. We have cracked open the ground, removed the fossil fuels, and released pollution upon the world.