ENLARGE Photo: Getty Images
National polls show that climate change is low on the list of voters’ priorities. For good reason: In the U.S., and for much of the world, the most dangerous environmental pollutants have been cleaned up. U.S. emissions of particulates, metals and varied gases—all of these: ozone, lead, carbon monoxide, oxides of nitrogen and sulfur—fell almost 70% between 1970 and 2014.
Further reductions will come from improved technologies such as catalytic removal of oxides of nitrogen and more-efficient sulfur scrubbers. This is a boon to human health.
But a myth persists that is both unscientific and immoral to perpetuate: that the beneficial gas carbon dioxide ranks among hazardous pollutants. It does not.
Unlike genuine pollutants, carbon dioxide (CO2) is an odorless, colorless gas. Every human being exhales about two pounds of CO2 a day, along with a similar amount of water vapor. CO2 is nontoxic to people and animals and is a vital nutrient to plants. It is also a greenhouse gas which helps maintain earth at a habitable temperature.
Fear of excessive warming from more CO2 in the atmosphere, including that released from human activity, has caused some people to advocate substantial and expensive reductions in CO2 emissions. But observations, such as those on our CO2 Coalition website, show that increased CO2 levels over the next century will cause modest and beneficial warming—perhaps as much as one degree Celsius (1.8 degrees Fahrenheit)—and that this will be an even larger benefit to agriculture than it is now. The costs of emissions regulations, which will be paid by everyone, will be punishingly high and will provide no benefits to most people anywhere in the world.
In 2013 the level of U.S. farm output was about 2.7 times its 1948 level, and productivity was growing at an average annual rate of 1.52%. From 2001 to 2013, world-wide, global output of total crop and livestock commodities was expanding at an average rate of 2.52% a year.
This higher food security reduces poverty and increases well being and self-sufficiency everywhere, especially in the poorest parts of the developing countries. Along with better plant varieties, cropping practices and fertilizer, CO2 has contributed to this welcome increase in productivity.
The increase of atmospheric CO2 following the Industrial Revolution also has facilitated the expansion of natural vegetation into what had been barren areas, such as the edges of the Sahara and the Arctic. According to the U.N., the world will add 2.5 billion people over the next 30 years, most of them in developing countries. Feeding these people and assuring them a comfortable living standard should be among our highest moral priorities. With more CO2 in the atmosphere, the challenge can and will be met.
National policies must make economic and environmental sense. When someone says, “climate science is settled,” remind them to check the facts. And recall the great physicist Richard Feynman’s remark: “No government has the right to decide on the truth of scientific principles.”
Mr. Nichols, a physicist, and Mr. Schmitt, a geologist and former Apollo 17 astronaut, are co-founders of the CO2 Coalition.