Thomas Hafeneth/creative commons

The best way to reduce your carbon footprint is one the government isn’t telling you about

Recycling and using public transit are all fine and good if you want to reduce your carbon footprint, but to truly make a difference you should have fewer children. That’s the conclusion of a new study in which researchers looked at 39 peer-reviewed papers, government reports, and web-based programs that assess how an individual’s lifestyle choices might shrink their personal share of emissions.

Many commonly promoted options, such as washing clothes in cold water or swapping incandescent bulbs for light-emitting diodes, have only a moderate impact (see chart, below), the team reports today in Environmental Research Letters. But four lifestyle choices had a major impact: Become a vegetarian, forego air travel, ditch your car, and—most significantly—have fewer children.

The top ways to reduce your carbon footprint

Credits: (Graphic) J. You/Science; (Data) Seth Wynes and Kimberly A Nicholas, Environmental Research Letters (2017)

Eating no meat cuts an individual’s carbon footprint by 820 kilograms of carbon dioxide (CO2) each year, on average, about four times the reduction they’d get by recycling as much as possible. (Emissions generated by eating meat result, in large part, from the large amounts of energy needed to grow, harvest, and process feed crops.) Foregoing one round-trip transatlantic flight each year would cut a person’s emissions of CO2 by 1600 kilograms. Getting rid of their car would reduce emissions by 2400 kilograms, or 2.4 metric tons. And by choosing to have one fewer child in their family, a person would trim their carbon footprint by a whopping 58.6 metric tons—about the same emissions savings as having nearly 700 teenagers recycle as much as possible for the rest of their lives.

Despite the effectiveness of these four measures, neither the textbooks in Canadian schools nor government reports or websites in the European Union, the United States, Canada, or Australia highlight these choices, possibly because most of them require such extreme changes in lifestyle.