Exhalation of methane and nitrous oxide adds to greenhouse gas emissions, researchers find.
Scientists in the United Kingdom have published new research suggesting that humans contribute to global warming by exhaling gases such as methane and nitrous oxide. The study, led by Dr. Nicholas Cowan from the UK Centre for Ecology and Hydrology in Edinburgh and published in the journal PLOS One, indicates that the gases inhaled and exhaled by humans make up about 0.1% of the UK’s greenhouse gas emissions.
The study focused on methane and nitrous oxide, both potent greenhouse gases, which are released in smaller quantities during exhalation. The researchers emphasized that while these emissions may seem negligible individually, their collective impact should not be ignored. The team acknowledged that the study only examined breath emissions and suggested that flatus emissions (farts) could significantly contribute to these values.
The researchers analyzed emissions from 104 adult volunteers in the UK and found that nitrous oxide was emitted by every participant, while methane was present in the breath of only 31% of participants. Those who did not exhale methane were likely to release it through flatus. The concentrations of these gases in the overall samples allowed the researchers to estimate the proportion of the UK’s emissions from human breath—0.05% for methane and 0.1% for nitrous oxide.
Interestingly, the study did not find a significant link between the gases in breath and dietary habits. The concentration of methane and nitrous oxide in the breath of both vegetarians and meat consumers was similar, suggesting that diet changes may not be a crucial factor when estimating emissions on a national scale.
The research underscores the need for a comprehensive understanding of all contributors to greenhouse gas emissions, including seemingly minor sources such as human breath, to develop effective strategies for mitigating climate change.