A typical two-person, very wealthy household — one with more than $1 million in investments in addition to a home and personal property — produces roughly 129 tons of planet-warming carbon dioxide per year, or about ten times the global average, according to a team led by Ilona M. Otto, a researcher at the Potsdam Institute for Climate Impact Research in Germany.

Of the 129 tons per year, about 10 come from driving, the team estimated, while powering homes generated close to 20 tons. But one habit accounted for more than half the emissions from very wealthy households: 67 tons of carbon dioxide came from frequent air travel.

Overall, emissions from the world’s wealthiest 0.5 percent produced up to 3.9 billion tons of carbon dioxide a year, or almost 15 percent of the world’s lifestyle-related carbon emissions , the researchers estimated. In comparison, the world’s poorest 50 percent have been estimated to be responsible for only about 10 percent of lifestyle emissions.

Dr. Otto and her colleagues defined lifestyle-related emissions as anything related to personal consumption choices — the heating and energy used at home, or in personal vehicles, or the emissions associated with flying, as well as the food and goods a household consumes — but not emissions related to infrastructure or the use of public services. Their findings were presented in the journal Nature Climate Change this year.

The research had a tiny sample size. The team conducted “lifestyle consumption surveys” with three very wealthy people, one based in the United States and two in South Korea. The researchers also interviewed the pilot of a private jet hired by wealthy customers, mostly in Europe.

Still, the findings loosely track an earlier analysis, by the Paris-based economists Lucas Chancel and Thomas Piketty, based on national G.D.P. and emissions data for 1998-2013. They found that the world’s top 10 percent of emitters contributed about 45 percent of global carbon dioxide emissions, while the bottom 50 percent contributed 13 percent. (They point out that the world’s top 10 percent of emitters are not just in heavily industrialized countries; a third of them are from developing countries.)