Global Warming Debate Settled?…Hardly!

A large majority of the world’s most renowned climatologists say global warming is real, caused mainly by increasing levels of carbon dioxide in the atmosphere. The dramatic increase, they say, is primarily due to man’s increased burning of fossil fuels. Some of their opponents cite research they claim prove any Earth warming is due to increased sun activity, and natural changes in carbon dioxide concentrations has very little to do with it. Some even go so far as to accuse the climatologists of perpetrating a vast hoax on the world even though they offer no credible evidence why such a large group of esteemed scientists would do so.

For lay people, like myself, who are not heavily invested in one position, deciding who is right is very difficult. After assessing the credentials, motives, and agendas of the individuals and groups promoting each position and using my limited scientific knowledge and common sense, I believe global warming’s fast rise is more likely than not being caused by man.

Read my other essays—“Global Warming and Death” and “We Got Trouble”—with this one to see which position you agree with.

Sometime when you have nothing else to think about, consider how elaborate and extensive Earth’s ecosystem has become and how vulnerable it is to natural events and selfish human activities. Most climatologists agree that man’s burning of fossil fuels and his selfish destruction of rainforests have greatly increased the concentration of carbon dioxide gas in our atmosphere, and is trapping more heat that is warming Earth at a faster rate than at any other time in its history. They differ only on the extent and timing of the warming’s present and future impact on the global ecosystem.

For 3.5 billion years, life forms have struggled to survive environmental changes caused by many devastating events such as Earth’s collisions with asteroids, comets and meteorites, volcanic eruptions, earthquakes, ice ages, wildfires, and violent storms. Individual members of species that had already evolved traits (physical or behavioral) that helped them adapt to these changes survived, and others did not. Over a long period of time surviving species have weaved a workable ecosystem for themselves in which they depend on each other for their survival. Fungi and bacteria eat dead organisms, insects eat other insects, still other insects eat plants’ nectar and return the favor by disseminating the plants’ seeds for them, plants make oxygen for animals to breathe, animals exhale carbon dioxide that plants use to make their food, animals depend on bacteria to help them digest their food, slowly building a longer and more complex food chain and food web into a very intricate and fragile global ecosystem.

The global ecosystem is composed of many smaller ones, each of which is composed of still smaller ones. The best way to visualize this is to think of an ecosystem as a pyramid. The system requires more members at the base to support fewer members above it. This is true all the way to the top. For example, in the sea huge numbers of dead and live plankton are required to feed bacteria and small fish. Many more small fish are required to feed fewer large fish and so on. The members at the base of the pyramid are more vulnerable to chemical pollutants, temperature changes and food scarcity because of their simpler and smaller size. When the base of the pyramid collapses the whole structure can as well. The plankton/carbon dioxide/water ecosystem is a good example of how a significant change in one ecosystem affects others.

• Plankton are very small drifting organisms that inhabit the water column of oceans and large fresh water lakes. There are two kinds: zooplankton and phytoplankton.
• Zooplankton occupy the cooler lower depths and phytoplankton live close to the surface.
• Zooplankton feed on phytoplankton and phytoplankton absorb sunlight and carbon dioxide from the atmosphere to manufacture their food. Phytoplankton populations remove more carbon dioxide from the atmosphere than all the other photosynthetic organisms(grasses, plants, algae, trees) combined.
• Both kinds of plankton require mineral nutrients(phosphates, nitrogen, silicates, etc.) in their diets.
• Nutrients are more concentrated and thus more available at lower and cooler depths but their distribution is more homogeneous when there is little variation in the water’s temperature from top to bottom.
• When water is heated, its density decreases, making it lighter.
• Scientists have found that warmer temperatures, due to global warming, is causing more separation of the warmer layer, where phytoplankton live, from the nutrient- rich cooler layer. The wider separation is denying phytoplankton populations access to enough of the nutrients they need for survival, causing a large reduction in phytoplankton populations worldwide.
• Melting ice in our polar regions during the last few decades have provided some cooling to our oceans, thereby preventing a more dramatic temperature rise that otherwise would have occurred. However, when the ice is gone temperatures will rise at a greater rate causing a wider gap between layers in the water column, which will shrink the size of phytoplankton populations even faster.

Many oceanographers and climatologists have concluded that even if we miraculously stopped all carbon dioxide emissions today, phytoplankton populations will continue to shrink for decades, leading them to predict dire consequences for Earth’s ecosystem. Of course, no one can really know what will happen in the future. Scientists, like all of us, can only guess, based on events that happened in the past under similar circumstances, which is why the global warming issue is still so contentious—and not “settled.”

Read Settled Science if you want to know why climatologists believe global warming is real, and largely man-made, and what its likely impact will be on our children and grandchildren’s future.