By the Highlands Conservancy Climate Change Committee.
There are a number of causes for climate change; some are natural and some are anthropogenic – man made. Greenhouse gases are the main drivers of climate change. Most greenhouse gases in the atmosphere are natural. Without water vapor, naturally occurring carbon dioxide (CO2), and other greenhouse gases, Earth would have an average temperature of 0º Fahrenheit (F) instead of the 59ºF that we currently enjoy. However, the burning of fossil fuels has significantly increased the amount of CO2 in the atmosphere and CO2 levels are greater today than at any time in the last 800,000 years (see https://www.climate.gov/news-features/understanding-climate/climate-change-atmospheric-carbon-dioxide ).
One can think of greenhouse gases acting as a blanket to keep heat in. The energy we receive from the sun in the form of sunshine is partially reflected back into space by clouds, snow, and ice; really anything white. The rest of the energy is absorbed by lands and oceans. At night this energy is radiated back into the atmosphere in the form of invisible infrared energy. Greenhouse gases absorb this outgoing infrared energy and get warmer, re-radiating energy both upward into space and downward toward the surface. The more greenhouse gasses in the atmosphere, the more energy that is re-radiated to the surface, and the warmer our climate becomes.
Not all greenhouse gases are the same. Methane, the main component of natural gas, is a potent greenhouse gas. Over a century, methane traps between 28 and 36 times more heat in the atmosphere than carbon dioxide does, according to the EPA. (See https://www.epa.gov/ghgemissions/understanding-global-warming-potentials). But methane breaks down over a relatively short time frame – about ten years.
That stands in stark contrast to carbon dioxide, which is a less potent greenhouse gas than methane, but is more prevalent and much longer lasting. “CO2 emissions cause increases in atmospheric concentration of CO2 that will last thousands of years” (emphasis added), according to the EPA. (Ibid.) That means that some of the emissions of carbon dioxide from the beginning of the Industrial Revolution in the 1850s are having an impact on our climate today. And it means that even if we stop burning all fossil fuels today, some of the carbon dioxide emissions already in the atmosphere will continue to affect the climate in 2100 and well beyond.
Two other facts about carbon dioxide are important. First, half of all the carbon dioxide put into the atmosphere since the beginning of the Industrial Revolution has been emitted in the last three decades – it really is the baby boomer generation that is largely responsible for fouling the atmosphere. Second, we already have too much carbon dioxide in the atmosphere. We reached a level of 416 parts per million (ppm) of carbon dioxide in the atmosphere in April 2020. Scientists believe that if we want to avoid the worst impacts of climate change, we need to reduce that level to 350 ppm.
Because of the long-lasting impact of CO2 and its concentrations in the atmosphere, simply reducing future carbon dioxide emissions is not enough. We will need to take carbon dioxide out of the air through natural means such as preserving existing trees and planting new trees or through technology. Next month’s version of ClimateWise will outline some of the basic options for reducing greenhouse gases in order to try and avoid the worst impacts of climate change.
This article is adapted from a longer publication, A Citizen’s Guide to Climate Change, which will be released in September by the West Virginia Climate Change Alliance. The Guide, according to the Alliance, is “written by West Virginians for West Virginians and for those who treasure our state.”