Two of the most important chemical reactions on earth are photosynthesis and respiration (cellular respiration, not just breathing). During photosynthesis plants take CO2(from the atmosphere) and water from the soil and make food (i.e. simple sugars) and convert them into more complex molecules while also releasing free oxygen. In the process energy is stored in food molecules (an example of anabolism, a building up process). During cellular respiration all organisms oxidize organic molecules and produce CO2 with the release of water molecules and more importantly energy is released. This is catabolism (a breaking down process). Anabolism and catabolism together are called metabolism. Thus the two reactions are complementary, that is, the reactants of photosynthesis (CO2 & H2O) become the products of respiration, and the raw materials of respiration (O2 & food molecules) become the products of photosynthesis. Inversely, the products of respiration (CO2 & H2O) become the raw materials for photosynthesis and the products of photosynthesis (O2 & food molecules) become the raw materials for respiration. Photosynthesis is represented by the forward reaction (left to right or green and respiration by the reverse reaction or blue)
Credit to: khanacademy.org
As a preview to the next essay, the diagram below suggests that the two processes are intimately related and that there is an energy flow from the sun to plants (photosynthesis) to all organisms (cellular respiration) with the building up and breaking down of adenosine triphosphate (ATP) with the subsequent release of energy-energy for all life processes. That is why we say that the ultimate source of our energy is the sun.
This is part of the “balance of nature”. Now let’s jump to rapid oxidation (burning) of –anything. Guess what? The products of burning are the same as those of cellular respiration, CO2 & H2O, and energy is released. Too much of one process or too little of the other and the “balance of nature” is upset. This is what is and has been happening for a long time. With increasingly more people on the planet, the rate of CO2 production is increasing at an alarming rate.
Carbon dioxide is heavier than oxygen (formula weight = 44 vs 32 for O2). Thus CO2 will hover closer to the earth. It and the other greenhouse gases (water vapor, methane, etc.) trap some of the sun’s energy thus preventing some of the infrared radiation from escaping into space thereby warming the atmosphere. The same phenomenon occurs on a cloudy vs. clear night. On which type of night does the temperature drop the least? Why?
It is interesting that CO2 levels vary with the seasons. During the summer when the Northern Hemisphere is tilted toward the sun, the leaves are actively capturing more CO2 which decreases its levels worldwide. During the winter when the Northern Hemisphere is tilted away from the sun and deciduous trees have dropped their leaves, less CO2 is captured and worldwide levels go up. You might ask “why doesn’t the Southern Hemisphere counterbalance that?” Taking a quick look at a globe should reveal the answer. Hint: compare the amount of land mass in the two hemispheres. Remember that land and the air above the land heat up faster and cool down faster than water does. There are some physical and chemical properties of water that I won’t go into here that account for that. But think about the fact that the temperature of land near large masses of water tends to stay cooler in summer and warmer in winter than land far away from large bodies of water. For example, compare the average temperature of Seattle to Omaha or Chicago’s lakefront vs. O’Hare Airport.
Now let’s look at the facts. First, let me remind you that neither I nor scientists worldwide and over many years are making up what I have described above and discuss below. Observations are made, data collected, and inferences are drawn. Principles of physics, chemistry, and biology as well as earth science and meteorology are intricately at work.
Average world temperature is and has been rising for years—no argument there, just recorded facts. That means that while some temperatures are normal or subnormal, many others are above normal. Don’t base your opinion on your microenvironment and say “no way, it’s just as cold here as it used to be”. I’m talking about average global temperature. The result is ocean temperatures rise and weather patterns are disrupted resulting in more severe storms (hurricanes, tornadoes, and floods) which may also occur in greater frequency. Warmer ocean temperatures results in stronger El Nino patterns and warmer ocean currents such as the Gulf Stream. Droughts become more severe and last longer. If you get the idea that all these factors (see paragraph four above) are related, then you know why I used the word “intricately”. Coincidently, the rate of greenhouse gases has been rising too.
I hope I have shared some important concepts to think about. I haven’t even touched on the effects of climate change on glaciers, living things, and even the seasons. That will come later
Published By
Larry Baumer
—
I graduated from Northern Illinois University in 1966 with a Bachelor of Science degree in Education and earned a Master of Science degree in Education also from NIU in 1973. I taught in the Harlem School District (5 years), a Chicago suburb (1 year), and the Rockford, IL School District for 27 years (26 at East High School). I culminated my teaching career at Kishwaukee College (8 years) Two important events occurred in 1988: I married my wife Angie and I received a summer teacher’s research fellowship through the University of Illinois School of Medicine at Rockford. My primary responsibility was light microscopy and Scanning electron miscroscopy of rabbit renal arteries (effect of high cholesterol diet). For 14 years I was a citizen scientist for the Illinois Department of Natural Resources in their RiverWatch program (monitoring water quality) My hobbies and activities include gardening, golfing, bowling, downhill and cross country skiing, photography, including photomicroscopy and time lapse photography, spending time with my wife and our dog, and in the winter playing around in my small home biology & chemistry lab.
Beyond what I have written in past profiles, in the early 1980’s I was an EMT with the Boone Volunteer Ambulance & Rescue Squad (BVARS) which fit in nicely with my science training and teaching. I also enjoy public speaking and made frequent scholarship presentations to graduating seniors and outstanding middle school students through the former Belvidere Y’ Men’s Club. I also made power point presentations of the RiverWatch program. But I most enjoyed making presentations at my high school reunions. Thanks guys for allowing me to do this.