Tailpipes and Chimneys Greening Gardens and Forests

By Vijay Jayaraj

A farmer in South Korea’s Gyeongbok Province carefully tends to his potato field, while halfway across the world the engines of a thousand cars idle on an American interstate highway. These seemingly disconnected scenes share a bond through the fertilization effect of atmospheric carbon dioxide, which has been greening the Earth for decades.

Yes, the CO₂ effluent of tailpipes and industrial flues are good for plants and all of life, contrary to the alarming tales that make this invisible gas an environmental bogeyman. Increasing CO₂ concentrations are literally making the world greener, and in many cases, it’s sending crop production to record levels.

A 2020 study, funded by Cooperative Research Program for Agriculture Science & Technology Development, reported that potatoes grown in an atmosphere of elevated CO₂—similar to what might be expected in coming decades—didn’t just survive but thrived!

The plants yielded a “distinct increase in growth and development and canopy net photosynthetic rate during tuber initiation and bulking. Consequently, biomass and canopy net photosynthesis increased, and tuber yield increased by 20.3%,” the researchers wrote.

This isn’t just good news for potato farmers. The CO₂ fertilization effect plays a role in the photosynthesis of all plants, and an increase in the gas acts as a kind of turbo boost. Significant increases in yields are seen in wheat, rice, soybeans and maize—all staple crops that feed billions.

As CO₂ concentrations rise, the water requirement for many plants decreases, making them more tolerant of drought – a scourge of farmers for millennia.

In the U.S. too, agriculture has flourished because of the additional CO₂ in the atmosphere, including in the agricultural heartland of the Midwest. As the data analysis in the CO₂ Coalition’s report on the Midwest shows, it is very clear that a warming climate and the atmosphere’s carbon dioxide composition are increasing crop yields in the Midwest’s corn and soybean regions. 

As Americans contribute roughly 14 metric tons of carbon dioxide per person annually, those emissions are fertilizing crops across the globe.

The greening effect extends far beyond agriculture. Satellite data from NASA has attributed the increased greenness over the past 35 years to the combined impact of elevated CO2 levels and optimal temperatures for plant growth. 

The rising emissions of China and India from their increased use of fossil fuels have contributed significantly to this global greening and has benefited ambitious tree-planting programs and intensive agriculture. Certain countries in Europe have registered an increase in forest area as well. In fact, “36 countries are gaining more trees than they’re losing,” reports the World Resources Institute.

In fact, the rate of greening due to CO₂ will be much higher than the rate of browning from the expansion of arid landscapes. Researchers at a Chinese university say that “by the end of this century, drylands will expand slightly by  approximately 5%, while vegetation productivity will increase by about 50%.” Elevated CO₂ impedes the expansion of drylands and “greatly promotes vegetation growth with increases in both leaf assimilation and canopy foliage,” they say.

Dr. Indur Goklany reports that 70% of Earth’s recent greening is attributed to emissions from the combustion of fossil fuels and that “fossil fuel dependent technologies have increased agricultural yields directly or indirectly by at least 167%.”

Whether it’s the tomato plants of Europe or the tropical forests in India, it’s clear that CO₂-enriched air is greening the planet, and we as a society have been positive contributors to that. You might say that CO₂ is the green energy for plant life.

This commentary was first published at California Globe on November 18, 2024.

Vijay Jayaraj is a Science and Research Associate at the CO₂ Coalition, Arlington, Virginia. He holds an M.S. in environmental sciences from the University of East Anglia and a postgraduate degree in energy management from Robert Gordon University, both in the U.K., and a bachelor’s in engineering from Anna University, India.