Climate change is real and has been since the formation of the planet. There are many factors that have contributed to climate change, such as warming and cooling cycles within the overall cooling of the earth, the upward and downward movement and changes in the shape of land masses, glaciation periods, vertical and horizontal ocean currents, wind currents and atmospheric conditions.

Additionally, the earth’s orbit around the sun is elliptical, not circular, and the earth’s tilt on its axis continually shifts. All of these have resulted in changes in sea-levels, shifts in biomes’ composition and location, and the characteristics of the land mass.

Underlying all of this is how energy flows through the earth’s ecosystems. Energy from the sun comes to the earth in several forms of radiation, including visible light energy, and exits the earth as heat energy. Photosynthesis by green plants converts light energy into chemical energy.

About half of the world users of carbon dioxide for photosynthesis are algae. This chemical energy is used immediately or stored. When the stored energy is used, it is usually converted to other energy forms. Every time the energy form changes, there is a reduction in the amount of useful energy (Second Law of Thermodynamics).

Atmospheric carbon dioxide changes also occur as a result of many natural causes. Examples include biological respiration by aerobic organisms, volcanic activity, and permafrost thawing that adds carbon dioxide to the atmosphere. There are even seasonal changes in the extraction rate during winter after leaf fall. Everything mentioned so far has nothing to do with the activities of Homo sapiens (human beings).

A brief review of the earth’s history will show some of the more significant changes and the outcomes of these changes. As glaciers expand and recede, sea levels rise and fall. A few thousand years ago, coastal land masses were above sea level. As sea levels rose that land became submerged.

There was no land connection between the American continents, Florida did not exist, and the Kansas-Nebraska area was an inland sea. With rising sea levels, the submergence of land will continue. Approximately 90% of the world’s major cities are located at coastal sites, which puts them in jeopardy. If the past three North American glaciations cycles continue at their past rates, we have a few thousand years of warming yet to go.

So, how do humans fit into the total picture of climate change? They are not the primary cause as indicated or implied by many researchers, the media, politicians and much of the general public. However, humans have altered the rate of change, which increases the magnitude of the effects. Examples of the effects of human activities include the more recent increases in the rate of sea level rising, increases in atmospheric carbon dioxide and other compounds from the combustion of fossil fuels, and deforestation that decreases the extraction of atmospheric carbon dioxide via photosynthesis.

As biomes shift, plants and animals evolve. Species become extinct, sometimes in large numbers, and new species evolve and survive. Nature abhors a vacuum. The vegetation that is characteristic of the coal mining areas now is not the vegetation that coal was formed from.

The earth’s human population is fast approaching 8 billion people. The “demands” placed by this many people are beginning to exceed the earth’s supply of resources. The “carrying capacity” of the earth can only support a finite amount of biomass. When, not if, the carrying capacity is exceeded, the results will be catastrophic. The population will suddenly drop to a fraction of what it is now.

So now what? No human effort will halt or reverse climate change. We must adapt to the coming changes by slowing the rate of change by whatever means possible. Reducing the demands on the earth’s carrying capacity by changing our lifestyles, switching to alternative energy sources and reducing the earth’s population among other options will help.

Will any of these and other suggestions happen at a significant level? Probably not, even though much of the public thinks the politicians can pass legislation that will fix everything. Who is going to give up their cars, their electrical appliances, their pleasurable activities and all the things that make living what it is today in the developed parts of the world? In addition, people in the underdeveloped locations are not going to cease their efforts to achieve the lifestyles of the developed countries.

Climate change is normal and global. Living and non-living things changed continuously in the past and will in the future. It won’t be like it is now. The earth is expected to be around for another 4-plus billion years. And human beings?

In final analysis, we adapt to that which we cannot change and fix what we realistically can.

R. Dean Decker, Ph.D., is a retired biology professor at the University of Richmond. Contact him at ddecker@richmond.edu.

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