The Story of
"Science is the acceptance of what works and the rejection of what does not. That needs more courage than we might think."
In this series, I hope to present climate change through simple physical principles most people are familiar with, or can easily comprehend. It is more important than ever to understand how climate change occurs and why it is a real issue today. While climate change is a natural process, with periods of warming and cooling tendencies, it can also be accelerated in either direction through abrupt and/or artificial processes.
I also hope this series and the other reports I've written about different concepts in science encourage you to continue researching these topics. Fascinating discoveries await!
Here's to education, because science matters.
Part 1: Energy, Inefficiency, and Thermodynamic Systems
May 28, 2017
by S. Alex Martin
What is climate change?
The central concept of climate change refers to the long-term amplification or radical shift of regional weather patterns due to a large build-up of gases that absorb or reflect heat in a planet’s atmosphere, thus preventing some of the heat from escaping back to outer space.
On Earth, the two most potent of these gases are carbon-dioxide (CO2) and methane (CH4). Methane is less abundant than carbon-dioxide, but is about 80-times more potent. On the flipside, 80% of carbon-dioxide can remain in the atmosphere for upwards of 200 years before dissolving into the ocean, while the remaining 20% can take thousands of years as it settles into soil and rock, or reacts with other chemical processes. Methane only remains for 12-20 years, and other gases, such as various nitrogen oxides, can last for tens-to-hundreds of years as well, each with varying potency.
Although much of the discussion surrounding climate change focuses on these two gases, the most abundant greenhouse gas (a gas that absorbs and retains heat) is actually water vapor (8). Water is a slow conductor of heat with a high heat capacity; therefore, it is able to absorb more heat energy over longer periods of time without a significant temperature increase, as compared to other molecules and materials that absorb and emit heat quickly. (It is for this exact reason—water’s slow transfer of heat energy—that, on a hot, sunny day at the beach, the sand can be burning your feet, but the ocean can feel cold, even though they are both receiving the same amount of energy from the sun.)
Is climate change a natural phenomenon?
Yes. Any celestial object able to sustain an atmosphere will experience cyclical, long-term (i.e. longer than 10,000 years) shifts in climate around the entire globe. Some changes are abrupt, triggered by low-frequency, high-impact events, such as supervolcano eruptions, large earthquakes that release vast quantities of gas trapped underground, and even asteroid impacts. Other changes are gradual, resulting from high-frequency, low-impact events, such as seasonal freezing and melting in arctic regions that affect glacial melting (causing freshwater to mix with saline water and, over time, will alter ocean currents), the thawing of the permafrost that releases gases trapped in the soil, and the shifting of tectonic plates (subduction zones), which can create entirely new volcanoes and island chains that develop their own ecosystems and weather patterns.
The natural phenomenon of climate change is cyclical, and generally takes tens-of-thousands to millions of years to warm or cool the average temperature of the Earth by even a few degrees. Gases released in warmer periods may become trapped again in the cooler periods. Natural disasters may alter landscapes and disrupt local air and water currents, which could go on to disrupt other air and water currents elsewhere around the planet. But because of the relative stability Earth’s ecosystems enjoy, long-term changes in global temperature and weather patterns remain miniscule, and warming or cooling tendencies therefore take thousands-to-millions of years.
What are energy efficiency and waste?
All systems in the universe require energy to function. For most of human society’s purposes, energy is formed when two or more substances react with each other and produce heat or electricity. However, there are no methods of producing energy that are 100% efficient. No matter how you produce energy, you will always lose some of it in the form of excess heat, sound, or physical waste. When you eat food, you produce solid and liquid waste. When you fill a gas tank and drive a car, you produce gaseous waste (easily seen on cold days as the “fog” spewing out of a tailpipe). When you ride a bike, you produce heat (friction) and liquid waste (sweat).
All waste is excess energy that is not being captured by the system it is being put into. If the human body was 100% efficient, we would not excrete any waste at all. No gas, solid, liquid, or heat would exit our bodies. All food we ate would be converted into usable energy. In fact, the average human body is only about 22% efficient (1). Of all the energy the human body consumes, about 78% is lost in the form of heat, gas, liquid, and solid waste.
This applies to all systems in the universe (a system is defined as an exchange of mass and/or energy between two or more materials). But for most of the universe, excess energy is lost in the form of heat and light. Sometimes, however, the heat and waste gets recycled into a different system, such as the heat Earth receives from the sun. Organisms on the surface of Earth, such as plants and algae, use solar heat and light to catalyze chemical reactions between CO2 and water—photosynthesis—and process other nutrients that aid the growth of the organism.
Numerically, many plants tend to be even less efficient at energy conversion than, say, humans. In one experiment, it was discovered that algae—which produces 70-80% of all the oxygen on Earth—is only 3% efficient (2). That is, 97% of the sunlight that hits the algae is reflected off and never used. But even though this seems to be an incredibly small figure, one must remember that plants receive energy non-stop (so long as the sun is visible), while humans tend to eat 2-3 meals per day, with occasional snacks—and many people tend not to eat the most energy-rich foods, or foods with the right types of energy. Plants, therefore, process an incredibly large amount of pure energy, and suddenly, that 3% efficiency is huge.
How does human activity produce waste?
The problem with human-accelerated climate change is not that we are affecting Earth’s natural systems, but the rate at which we are affecting these natural systems. In the same way, the driving factor behind human-accelerated climate change is not human industry, but the inefficiency of human industry.
Life on Earth is carbon-based. Carbon can make up to four bonds with other elements at once, the most of any element on the periodic table, making it the simplest, most statistically-probable way we know life can form. As a result, carbon accounts for 60-70% of the waste produced when living organisms die. Over millions of years, exposure to heat and extreme pressure underneath the earth’s crust causes carbon to form oil, coal, and other fossil fuels (so named because that’s what most of these fuels are made of: the fossils of once-living organisms).
Deep underground, the carbon found in fossil fuels is independent of the systems acting on the earth’s surface. That is to say, most of Earth’s ecosystems and life evolved without the presence of massive quantities of carbon and other gases that are usually trapped underground. But with the advent of the industrial revolution, coal was mined at unprecedented rates. And with the discovery of petroleum, oil fields became the single-largest national asset for wealthy developed countries. Hundreds of oil rigs sprang up on every settled continent and in every ocean (prior to petroleum, most oil was manufactured from whale blubber, and only for rudimentary purposes; notably, lamp oil and soap).
All told, it wasn’t until the first industrial revolution that massive quantities of carbon, methane, nitrogen oxide, and other greenhouse gases and particulate matter began being introduced to Earth’s atmosphere through artificial means at a grossly unnatural rate. Earth’s major life forms and ecosystems simply do not have enough time to evolve or safely adapt to these abrupt changes.
When petroleum was discovered in 1859, the world’s human population was 1.3 billion (4). In 1938, when the population was 2.4 billion, oil was discovered in Saudi Arabia. 20 years later, in 1960, the population reached 3 billion. The population explosion between 1960 and 1999 saw the human population double to 6 billion. Today, there are more than 7.5 billion people. Combined, fossil fuels still account for 80.81% of the world’s energy production (5). If you were to divide the world’s population according to energy usage, 6 billion people would rely on fossil fuels, and only 1.5 billion would be using alternative and renewable sources.
When you burn gasoline, the waste products—e.g. carbon dioxide, carbon monoxide, sulfur dioxide—blow out of your tailpipe and mix into the atmosphere. The waste doesn’t condense into more gasoline and go back into your gas tank so you can keep using it. This is because the internal combustion engine, the engine inside all traditional cars, literally changes the chemical composition of gasoline. What comes out the tailpipe is chemically different from what went in the gas tank. Coal-fired electric plants are the same way: the coal burns and heats a large amount of water, which expands and evaporates into steam that spins a turbine (3). The motion of the turbine, combined with a magnetic field, generates electricity. The steam condenses back into water and is recycled (though heat energy is lost in the process, becoming a waste product). But the coal cannot be used again. It burns, expels nitrogen oxide, sulfur dioxide, mercury, heat, and other wastes, and is then disposed. What comes out is not the same as what went in.
Tying it together: how do thermodynamic systems dictate that human-accelerated climate change MUST occur?
There are three types of thermodynamic systems (energy-transfer systems) in the universe: isolated, open, and closed. The conservation of mass and energy says that no mass or energy existing in an isolated system can be lost or gained. In our current understanding of physics, however, a truly isolated system cannot exist naturally or artificially. Therefore, the only system assumed isolated in all of science is the universe itself, and even that is just a hypothesis.
An open system is one which regularly exchanges mass and energy with other systems as a regular part of its natural cycle. The sun is an open system, because it radiates heat and expels mass (but it can also gain mass through comets, space probes, and other objects impacting it, though the increase is essentially zero). The ocean, too, is an open system. It naturally absorbs and expels heat, and collects and loses water and particle mass through evaporation and condensation, more commonly known as the water cycle.
A closed system regularly loses or gains energy, but not mass, as part of its natural cycle. In this way, the Earth is a closed system. It absorbs heat and other radiation from the sun, which give energy to Earth’s ecosystems, life forms, and natural cycles (e.g. weather patterns). It does not, however, lose or gain mass in order to maintain these natural cycles.
Some systems can exist within other systems. Earth as a single celestial object is a closed system, but on Earth, there are several open systems. The atmosphere, that is, all the air above the surface of the Earth, is one example. Molecules in the atmosphere absorb and radiate heat, and particulate matter (dust, chips of debris, etc) are constantly being emitted, captured, and “processed” in the cycle (e.g. smokestacks release particulate matter that in turn form raindrops, because raindrops condensate around atmospheric dust, termed: condensation nuclei).
Coal, oil, and other fossil fuels can come from miles under the Earth’s crust. Naturally, they are independent, totally separated from atmospheric systems. And just digging or drilling them up doesn’t immediately introduce them to external systems, either, unless there’s an onsite disaster, such as a spill or fire. Statistically, however, major spills are few and far between. Spills do occur with relative frequency, and all have an impact on the immediate environment, but since 1970, there has been a significant drop in “large oil spills” in the ocean (defined here as spills that lose more than 772 tons of oil). Large ocean tanker spills alone have declined 93.1% since 1970 (6). In fact, the leading cause of major spills is human negligence, either from ignoring, missing, or misinterpreting anomalies that lead to the disaster.
But let’s assume that the fossil fuels are successfully collected, refined, and transported to consumers. Now they’re in the hands of industrial plants, utility companies, public and private transportation, and other consumers. In the typical vehicle with an internal combustion engine, about 61% of the fuel energy is lost as heat and internal friction. Accounting for air drag, wheel-to-surface friction, and braking friction, the efficiency of a modern vehicle drops to below 35% (7). Essentially, only a little more than 1/3 of the gas you put into your car actually makes it drive. More than 60% of it transforms into heat and greenhouse gases (exhaust waste).
This is where the conservation of mass and energy comes in. Until companies extracted them, fossil fuels were contained underground, totally separated from surface systems. The atmospheric concentration of all the carbon dioxide, methane, and other greenhouse gases had remained just about the same for at least tens-of-thousands of years, because there were virtually zero chemical reactions producing these gases in excess at the Earth’s surface. But then they were extracted, refined, and used as fuel. Suddenly, and at every step of the fossil fuels’ industrial cycles, the chemical reactions became widespread, and have been happening every second of every day for the better part of the past one and a half centuries.
More chemical and particulate mass has been entering the atmosphere than leaving it—and the gap is expanding at an accelerating rate, caught in a positive feedback loop. As discussed at the beginning of this report, it takes individual methane molecules 12-20 years to leave the atmosphere, individual carbon-dioxide molecules 200 years at the very least, and a range of years for other greenhouse gases. This is causing the atmosphere to become relatively dense with heat-trapping molecules, compared with long-term chemical stability Earth’s ecosystems are accustomed to. More heat is remaining close to the surface of Earth, rather than being reflected into space, so energy that usually escapes into space is being collected and added to Earth’s systems. For Earth, this is not a problem. The planet will keep spinning. But for life on Earth, life that evolved under stable conditions—including humans, because we are animals, too—the growing chemical imbalance will have escalating consequences.
The story of climate change will continue...
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Alex Martin is the author of six futuristic science-fiction novels. He's also a science communicator, and has given several assemblies at schools, colleges, bookstores, and libraries. The Experience Daliona website is an extension of his books and a representation of his greatest passions.