On the Topic of Cimate Change
July 14, 2022
As expected, my identically titled column from the June 30 paper was met with some criticism and I appreciate the feedback. In this column, I want to discuss Greenhouse Gases and how they impact our atmosphere and thus, our climate.
Global Warming Potential
There are several classes of Greenhouse Gases (GHGs) contributing to climate change on different levels. These classes are Carbon Dioxide (CO2), Methane (CH4), Nitrous Oxide (N2O), and Industrial Gases (Hydrofluorocarbons, Perfluorocarbons, Sulfur hexafluoride and Nitrogen trifluoride). According to the Energy Information Administration (EIA), water vapor is omitted from this list despite being the most abundant GHG because, “most scientists believe that water vapor produced directly by human activity contributes very little to the amount of water vapor in the atmosphere” (2021). It is also important to consider the GWP of water vapor, which has a “near-zero or small cooling effect” (Sherwood, et al., 2018.) While water vapor is indeed the most prevalent greenhouse gas, its effect on global warming is considered negligible or even in opposition to global warming. Thus, water vapor is not a dominant driver of the Greenhouse Effect and may in fact be acting in opposition of the GHGs listed above.
When scientists discuss the Global Warming Potentials (GWPs) of these gases it is based on Carbon Dioxide, specifically the energy absorbed by the gas over a given period (usually a century), so CO2 has a GWP of 1 for 100 years. All other listed gases are many times more potent GHGs than CO2, with the Industrial Gases being several thousand times more potent.
Carbon Dioxide is the most discussed GHG within the context of global warming as it is extremely prevalent and perhaps the easiest to understand. There are natural processes that produce carbon dioxide as well, such as decomposition, ocean release, and respiration. However, climate scientists are not concerned with these natural releases as they are considered as close to fixed amounts within the Earth system.
Climate scientists are worried about human-emitted CO2, which happens primarily through the combustion of fossil fuels, such as coal, natural gas, and petroleum products, humans emit Carbon Dioxide to generate electricity, heat, and transportation. According to the Environmental Protection Agency (EPA), the U.S. alone produced an estimated 5,222 million metric tons (5,744 million short tons) of CO2 in 2020. This is approximately 15,737 the times the weight of the Empire State Building. When humans produce this much CO2, the Carbon Cycle cannot compensate for the levels of atmospheric CO2 which is introduced into the Earth system because of human activity.
No scientist argues for the complete removal of Carbon Dioxide from the system, but they do argue to address the CO2 contributed by humans. Carbon Dioxide itself is not the problem, but the amount of it is. This can be compared to eating food; an appropriate amount of food is a very good thing, but the problem is at its genesis when food is overindulged. The line between homeostasis and excess can be a fine one, in which walking the metaphorical tightrope is extremely important.
Unfortunately, it has become the tendency of some to deny the existence of this tightrope completely.
Climate Change is not a political issue; it is a human issue. To attempt packaging climate change into a box which it frankly does not fit is to ignore the widespread implications of the thing itself. Please do not reduce this issue to the confines of our two-party system, it is much larger than that. It is a tidal wave, easily washing over the arbitrary lines we draw in the sand.
This story is supported by a grant through Wyoming’s Established Program to Stimulate Competitive Research (EPSCOR) and The National Science Foundation.