The Four Most Effective Things You Can Do About Climate Change, According To Science

Science has spoken the words that governments dare not say. Two scientists completed an extensive review of individual actions that can be taken to mitigate climate change, and they are not the actions governments and textbooks tend to urge upon people across the world.
"We recommend four widely applicable high-impact (i.e. low emissions) actions with the potential to contribute to systemic change and substantially reduce annual personal emissions," write Seth Wynes of Sweden's Lund University and Kimberly Nicholas of the University of British Columbia, in an article published Wednesday in the journal Environmental Research Letters.
The four recommendations are not the actions that you've been hearing about from your government, such as recycling, switching to more efficient light bulbs, purchasing green energy or driving an electric car. Those actions, while valuable, are not nearly as effective as the four listed below. Wynes and Nicholas surveyed government materials and high-school textbooks to determine whether the most effective actions are being recommended and found they are not.
"Though adolescents poised to establish lifelong patterns are an important target group for promoting high-impact actions, we find that ten high school science textbooks from Canada largely fail to mention these actions," the authors write, "instead focusing on incremental changes with much smaller potential emissions reductions. Government resources on climate change from the EU, USA, Canada, and Australia also focus recommendations on lower-impact actions."
The four most effective actions, according to Wynes and Nicholas, are:
4 Eat A Plant-Based Diet
Abstaining from meat can save up to 1.6 metric tones of emissions per year, Wynes and Nicholas say. They acknowledge the difficulty of implementing this recommendation in a society that associates meat with wealth, status and luxury. "However, even knowledgeable and willing individuals may not reduce meat intake or adopt other high impact actions if cultural norms or structural barriers act as obstacles," they write.
Even so, they note that it is far more effective to abstain from all meat than to follow the compromise recommendation often presented in textbooks and guides, which urges people to eat less meat. "Eating a plant-based diet was presented in the form of moderate-impact actions such as eating less meat, even though a completely plant-based diet can be 2 to 4.7 times more effective at reducing greenhouse gas emissions than decreased meat intake," they write. And a plant-based diet reduces emissions far more than many other actions governments have pursued. One text urges teens to switch from plastic bags to reusable bags, the authors note, an action that is only 1 percent as effective as giving up meat for one year.
Emissions stack up quickly when people engage in more than one harmful action. If the world is to meet a carbon budget that keeps the average global surface temperature from increasing more than 2ºC, each individual has to emit no more than 2.1 metric tons of carbon per year. "We estimate that an individual who eats meat and takes one roundtrip, transatlantic flight per year emits 2.4 tCO2e (metric tons of CO2-equivalent emissions) through these actions, exhausting their personal carbon budget, without accounting for any other emissions. It would help meet climate goals if such an individual chose to shift her or his behaviour, as technological advances may be unable to sufficiently reduce emissions from these two actions even by 2050."
The good news is, people who combine the four helpful actions listed above can drastically reduce emissions much faster than governments can.
"National policies and major energy transformations often take decades to change locked-in infrastructure and institutions," the authors write, "but behavioural shifts have the potential to be more rapid and widespread."
3 Do Not Fly
Airline flights remain one of the more dogged emissions sources. World leaders hope to eventually power planes with bio-fuels, rendering them carbon neutral, but that technology is a long way from implementation. Until that happens, airplanes will continue to be a source of harmful carbon emissions. Skipping one flight can save up to 2.8 metric tons of emissions per year, Wynes and Nicholas say.
2 Live Car-Free
Buying an electric car can reduce emissions if the electricity comes from non-emitting sources, such as solar, wind, and nuclear power. Even then, the carbon emissions caused by the construction and transportation of the car take a bite out of its lifetime carbon savings, and car dependency requires emissions in other sectors as well. "Living car-free reduces the need to build more roads and parking spaces, and supports higher-density urban design, which more efficient cars do not," Wynes and Nicholas say. Living car free equates to saving one to 5.3 metric tons of emissions per year.
1 Have One Less Child
Each child born in the developed world contributes an average of 58.6 tonnes of CO2-equivalent emissions per year, according to Wynes and Nicholas. The American child's footprint is much larger: 117 tons per year. If people eliminate those emissions by having one less child, that action dwarfs any other action they can take. Scientists have issued this caution before. In 2009 statisticians at Oregon State University warned that each American child multiplies its mother's carbon footprint nearly six times, swamping any emissions savings she might produce by switching to energy-saving appliances and cars, driving less and recycling more. At the time, each child born in China had about one-seventh that impact. The 2009 study focused on mothers, even though fathers, too, contribute to child creation and the resulting emissions. In the new study, Wynes and Nicholas rely on established literature on the carbon impact of each child born in the developed world—which China will soon join—and they attribute half of that child's impact to each parent. The study considers future generations as well, assigning one quarter of that child's offspring (the grandchildren) to each parent, and so forth. "This is consistent with our use of research employing the fullest possible life cycle approach in order to capture the magnitude of emissions decisions." Having one fewer child equates to saving 24 to 118 metric tons of carbon emissions per year, depending on region, they say.