Humans Are Fueling Global Warming By Just Breathing, Study Claims

Scientists in the United Kingdom have published new research that claims that humans are exhaling global warming-causing gases when they breathe. The study has been published in the journal PLOS One. Experts explained that methane and nitrous oxide in the air we exhale make up to 0.1% of the UK's greenhouse gas emissions. So once you factor in the farts and burps being produced by humans, it becomes clear that humans are fueling global warming by just exhaling from lungs, scientists said. 

The new study was led by Dr Nicholas Cowan from the UK Centre for Ecology and Hydrology in Edinburgh. In the paper, she said that the evidence of planet-killing breathing is pretty clear and it shouldn't be ignored. "We would urge caution in the assumption that emissions from humans are negligible," she said. 

The team of researchers explained that when humans inhale, air enters the lungs and oxygen from that air moves to the blood, while carbon dioxide (CO2), a waste gas, moves from the blood to the lungs and is breathed out. Every person breathes out CO2 when they exhale, but in the new study, researchers focused on methane and nitrous oxide. They explained that these two are both powerful greenhouse gases, but because they are breathed out in much smaller quantities, their contribution to global warming may have been overlooked.

"We report only emissions in breath in this study, and flatus emissions are likely to increase these values significantly, though no literature characterises these emissions for people in the UK," the team wrote in the study. "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. 

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For the study, the researchers investigated emissions of methane and nitrous oxide in human breath from 104 adult volunteers in the UK. After analysing they found that nitrous oxide was emitted by every participant, but methane was found in the breath of only 31 per cent of participants. The team said that those who do not exhale methane in their breath are still likely to "release gas ion flatus", meaning by farting or burping. 

Therefore, concentrations of the two gases in the overall samples let the researchers estimate the proportion of the UK's emissions from human breath - 0.05 per cent for methane and 0.1 per cent for nitrous oxide.

Researchers didn't manage to find any link between gases in the breath and diets. "Concentration enhancement of both CH4 and N2O in the breath of vegetarians and meat consumers are similar in magnitude. 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 across the UK as a whole," the study read.