As the nation shifts abruptly into the fight against coronavirus, a question arises: could social isolation help reduce an individual’s production of greenhouse gases and end up having unexpected consequences for climate change?

The biggest sources of carbon emissions caused by our lifestyles come from three activities, said Kimberly Nicholas, a researcher at the Lund University Center for Sustainability Studies in Sweden: "Any time you can avoid getting on a plane, getting in a car or eating animal products, that’s a substantial climate savings." Many people trying to avoid the coronavirus are already two-thirds of the way there.

Christopher M. Jones, lead developer at the CoolClimate Network, an applied research consortium at the U.C. Berkeley Renewable and Appropriate Energy Laboratory, said that "all these extra precautions that schools and businesses are taking to keep people home are saving lives, and that’s clearly what’s most important." Having said that, he added that many of the actions people are taking in response to the coronavirus outbreak could have a benefit of a reduced carbon footprint — though others would have little effect or could even expand it.

Here are four areas we may see changes in greenhouse gas emissions because of the coronavirus.

Transportation: Big Reductions

People are staying home and flying less. That’s good for the planet, Dr. Nicholas said. "For average Americans, the biggest source of greenhouse gas emissions is driving," she said. Anything that reduces driving, including working from home, "has a big impact on our climate pollution." Avoiding air travel can have a large effect as well: one round-trip flight from New York to London, she said, produces as much greenhouse gas emissions as the preventive climate impact of nearly eight years of recycling. Dr. Nicholas was an author of a 2018 study that examines greenhouse gas emissions reductions in actions people take to fight climate change, and is currently writing a book about personal action and the climate crisis.

The actual effects on your greenhouse gas emissions of staying home will greatly depend on where you live, Dr. Jones said. For the roughly 25 percent of Americans living in the suburbs and another 25 percent in rural areas, cutting out a commute often means driving far less. But about 50 percent of Americans live in urban areas, and for those who use mass transit, avoiding a commute doesn’t necessarily cause much of a dip in emissions. The University of California, Berkeley, has suspended in-person instruction, and Dr. Jones said, "I commute by train and the train is going with or without me and everyone else, so I don’t think there’s an impact there."

Food: A Big Maybe

Dr. Jones has done research into the relative carbon footprints of dining at home or dining out, but, so far, the results are fuzzy. "We don’t have conclusive evidence yet," he said, citing the comparative efficiency benefits of eating out and the waste involved in making meals at home. "We waste about 25 percent of the food that we buy," he said. If you drive long distances to go to a favorite place — like Austinites who drive more than 30 miles to Lockhart, Tex., for excellent barbecue, "that’s going to swamp the emissions from your food."

Dr. Nicholas said that where you eat is not as important as what you eat; "eating beef has a disproportionate climate impact," she said, while eating foods "lower on the food chain" such as plants results in a much smaller carbon footprint. So here’s your chance for a twofer: save the planet by working down the stockpiles of rice and beans that you panic-bought along with all that toilet paper.

At Home: It’s Still Location, Location, Location
For people who turn their thermostats down while they are out of the house, staying home means more heat, and more greenhouse gases. But when it comes to the greenhouse gas impact of heating your home, "Where you live is by far the biggest factor in determining your carbon footprint," Dr. Jones said. "If you live in a cold climate, heating your home can more than offset the savings from driving your vehicle."

The energy mix where you live also matters: much of the Northeast still depends on coal to produce power, while California has relatively lower-carbon power sources, getting 31 percent of its electricity from renewable energy and only around 3 percent from coal.

Shopping: More, Less, Differently?

If you’re at home staring at your computer without the prying eyes of your co-workers, you may be tempted to shop online a bit more. Or maybe you’ll avoid the supermarket or mass transit by ordering your groceries. A bump in online shopping might be bad for your wallet, but it could be good for the planet, Dr. Nicholas said. She cited research suggesting that people who decide to use online ordering and package delivery could well be reducing their effect on climate change, thanks to the benefits of logistically organized, centralized delivery routes and driving less. "I would expect in general that having fewer vehicles on the road is better for the climate," she said. (While online shopping can reduce greenhouse gases, it is most effective when you order in bulk to limit the number of trips delivery vehicles make to your home.)

Will any of the low-carbon behaviors that people have adopted persist after the crisis passes? Charles Duhigg, the author of "The Power of Habit" and a former New York Times reporter, said habits built over lifetimes are hard to shake. "As soon as the environment becomes stable again, the habit starts to reassert itself" unless there is a "powerful reward" to the new behavior.

Mr. Duhigg said that while there is no set time for a habit to form or change, some cultural habits could, if the pandemic response lasts long enough, take hold. One example: shaking hands. "I could see other kinds of behavior replacing that habit, or maybe just diminishing," and wondered aloud whether his own children might one day think "hand shaking is a weird, old-timey thing."

Some practices, like videoconferencing and telecommuting, may gain ground, Mr. Duhigg said, for a reward of saved time and trouble. He expressed doubts, however, that leisure travel behavior would see a similar shift. "It seems unlikely to me that people will say, ‘You know, I loved not taking vacations. I learned staying at home with my kids is so rewarding!’"

Dr. Nicholas, who makes an effort to fly less for conferences, said the best result of this epidemic could be "finding new ways to work and collaborate and learn and study and share, with less physical travel," she said.

Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, said that the disease, for all of the pain and destruction it is causing, can teach important lessons. "It’s unfortunate to learn it this way, but we’re learning we can do a whole lot more today in terms of what we do, how we do it and where we do it."

"Never waste even a tragic crisis," he said.