A new study suggests that humans may be contributing to global warming by breathing.
“Exhaled human breath can contain small, elevated concentrations of methane (CH4) and nitrous oxide (N2O), both of which contribute to global warming,” according to research released last week in the UK journal PLOS.
According to the report, the methane and nitrous oxide exhaled by humans account for about 0.1 percent of the UK’s greenhouse gas emissions.
In addition to carbon dioxide, humans expel other gases.
The study, led by Dr. Nicholas Cowan of the UK Center for Ecology and Hydrology, included 104 adult volunteers and discovered that every one of them exhaled nitrous oxide, while 31% exhaled methane.
Those who did not exhale methane in their breath still likely released the gas “ion flatus,” which refers to burping and flatulence, according to the study.
104 adult volunteers participated in the study
“We report only emissions in breath in this study, and flatus emissions are likely to increase these values significantly, though no literature characterizes these emissions for people in the UK,” the research team wrote.
“Assuming that livestock and other wild animals also exhale emissions of N2O, there may still be a small but significant unaccounted-for source of N2O emissions in the UK, which could account for more than 1% of national-scale emissions,” they added.
Researchers estimated that human breath accounts for 0.05 percent of methane emissions and 0.1 percent of nitrous oxide emissions in the UK based on gas concentrations in study samples.
The study found no link between exhaled gasses and diet.
“Concentration enhancement of both CH4 and N2O in the breath of vegetarians and meat consumers are similar in magnitude,” the researchers said. “Based on these results, we can state that, when estimating emissions from a population within the UK, diet or future diet changes are unlikely to be important when estimating emissions [exhale] across the UK as a whole.”
