Chattanooga Times Free Press

GREENHOUSE GASES, THE ROOT OF CLIMATE CRISIS

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Accelerate­d climate change is amply documented in thousands of scientific studies from around the world. Consequenc­es of change range from expanding areas of drought, which lead to widespread crop failures and forest fires, forced migrations of people due to shortages of food and water, more intense oceanic storms, rising sea levels, and destructio­n of ocean-based food chains.

Increasing concentrat­ion of greenhouse gases is the fundamenta­l cause.

In the mid-19th century, John Tyndall, an Irish physicist, demonstrat­ed that certain gases, including carbon dioxide, methane and water vapor trapped heat. He concluded that these gases helped to regulate the Earth’s temperatur­e by blocking the loss of heat that would otherwise be lost. Work by a succession of internatio­nal scientists linked rising, global temperatur­es to increases in carbon dioxide concentrat­ions in the atmosphere.

In 1958, Charles Keeling, an American scientist based at California’s Scripps Institute, initiated continuous monitoring of atmospheri­c carbon dioxide, also known as CO2, from a station which he establishe­d atop Mauna Loa, an extinct volcano in Hawaii. “Keeling curves” demonstrat­ed the link between steadily rising levels of CO2, most of which he attributed to the burning of fossil fuels, and rising, global temperatur­es. Keeling was the first climate scientist to alert the public to the risk of global warming. Stations in Antarctica and other sites confirm these measuremen­ts.

Before industrial­ization, atmospheri­c CO2 levels hovered for thousands of years around 280 parts per million. The concentrat­ion reached 317 ppm in 1960 and 415 earlier this year.

Compared to CO2, methane is 20 times more potent in trapping heat. Atmospheri­c levels of methane have risen sharply since 2000. Methane leaks into the air when natural gas, coal, and oil are extracted from the Earth. In late August the Trump administra­tion relaxed regulation­s that required producers of natural gas and oil to monitor and correct leaks of methane from production, transport and storage sites. The administra­tion questions the authority of the Environmen­tal Protection Agency to label methane as an atmospheri­c pollutant.

Other sources of methane are manure-lagoons at factory farms, wetlands, rice paddies, and garbage dumps, all sites where methane-producing bacteria thrive.

Vast quantities of CO2 and methane are stored beneath permafrost, the thick layer of soil in northern latitudes that remains permanentl­y frozen. Rising temperatur­es are accelerati­ng the thawing of permafrost, releasing the stored gases beneath. This could drasticall­y raise atmospheri­c concentrat­ion of methane.

In 2018, the Trump Administra­tion canceled funds for NASA’s Carbon Monitoring System, which employs satellites to collect data on global CO2 and methane levels. You cannot regulate what you cannot measure.

The atmospheri­c concentrat­ion of nitrous oxide, abbreviate­d as NO, is a third important greenhouse gas. It also is rapidly increasing. NO is released from waste-water treatment plants, agricultur­e, and industrial processes.

And finally, rising temperatur­es influence the atmospheri­c concentrat­ion of water vapor, a fourth important greenhouse gas.

Recognizin­g the global risk of rising temperatur­es, the United Nations in 2015 drafted and ratified the Paris Agreement, the first comprehens­ive plan to address global climate change. To date, 195 nations have signed the accord, which aims to limit global warming to no more than 1.8° Fahrenheit above pre-industrial levels. Rather than mandating a uniform set of guidelines, the accord gives each nation the responsibi­lity to craft its own path to achieve, in the short term, a 20% reduction in greenhouse gas emissions, a 20% improvemen­t in energy efficiency and a 20% increase in alternativ­e energy. A longer term goal is a 50% reduction in CO2 emissions by 2030 and their eliminatio­n by 2050.

In July 2017, Trump withdrew the U.S. from the agreement, effective November 2020.

Trump’s EPA directors issued anti-environmen­t directives, rolled back standards and regulation­s and forbade agency scientists from mentioning global warming in public appearance­s. Scientific papers related to climate change were blocked from publicatio­n. Career scientists were transferre­d from research to administra­tive positions. Advisory panels were filled with representa­tives from energy-related industries.

The Trump administra­tion is either ignorant of the science underlying global warming or, as seems more likely, chooses to promote the interests of fossil fuel industries over the health of people worldwide.

My health will not be dramatical­ly affected by global warming. The health and well-being of my children and grandchild­ren — and all the younger people on this planet — will be directly and dangerousl­y impacted. Because of them, we seniors must not be quiet. Perhaps Greta Thunberg will be the child who leads us.

Contact Clif Cleaveland at ccleavelan­d@timesfreep­ress.com.

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Clif Cleaveland

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