Does Breathing Contribute to Global Warming?

I was astonished and vexed by a recent report disturbingly suggesting that human breathing contributes to global warming and that the methane and nitrous oxide found in human exhalations are worse for the environment than carbon dioxide. According to a study published last month in PLoS One, a peer-reviewed Journal of Science and Medicine published by the Public Library of Science, human respiration’s contribution to climate change has been underestimated and merits further study.

The report said after measuring the gas composition in the exhaled breaths of 328 study participants, the researchers concluded human breath comprises 0.05% of the United Kingdom’s methane emissions and 0.1% of its nitrous oxide. The study noted that both gasses “have a much higher global warming potential than carbon dioxide.”

The researchers, led by atmospheric physicist Nicholas Cowan of the UK Centre for Ecology and Hydrology, wrote: “Exhaled human breath can contain small, elevated concentrations of methane (CH4) and nitrous oxide (N2O), both of which contribute to global warming. We would urge caution in the assumption that emissions from humans are negligible.”

While Cowan explained that “CO2 contribution in human breath to climate change is essentially zero” because plants absorb nearly all the carbon dioxide humans breathe out, the other two gasses are left in the atmosphere.

The claims made by scientists regarding the environmental impact of methane and nitrous oxide emissions associated with human exhalations, comparing their effects to those of carbon dioxide has far reaching ramifications and it is deeply worrisome.

The study suggesting that human breathing contributes to global warming is likely to directly lead to calls and agitations to reduce population growth. Reducing global population has been a topic of discussion in the context of environmental conservation and sustainable development for many years. However, it is important to note that population growth is a complex issue influenced by various social, economic, and cultural factors. Now with the introduction of human breathing into the debate on the greenhouse gas emissions, my concern is it would potentially generate and fuel calls for the reduction of world population.

Global warming is a pressing environmental issue that has garnered significant attention in recent years. Before delving into the specific effects of human breathing on global warming, it is crucial to understand the role of greenhouse gases in the Earth’s atmosphere. Greenhouse gases trap heat from the sun, leading to the greenhouse effect and an increase in global temperatures. The most prevalent greenhouse gas is carbon dioxide (CO2), primarily generated by human activities such as burning fossil fuels, deforestation, and industrial processes. Methane (CH4) and nitrous oxide (N2O) are two additional greenhouse gases that contribute to global warming, albeit in smaller quantities. Methane is released during the production and transport of coal, oil, and natural gas, as well as through agricultural practices and waste management. Nitrous oxide is primarily emitted from agricultural and industrial activities, as well as the burning of fossil fuels.

Human breathing is a natural biological process that involves the inhalation of oxygen and the exhalation of carbon dioxide. While the sheer volume of carbon dioxide released through human respiration is relatively small compared to other sources, scientists have raised concerns about the potential emissions of methane and nitrous oxide associated with human breath. The main argument centers around the fact that these gases are released in higher concentrations per exhaled breath compared to carbon dioxide.

To evaluate the claim that methane and nitrous oxide found in human exhalations are worse for the environment than carbon dioxide, it is essential to examine their respective global warming potentials (GWPs). GWP is a measure of how much heat a greenhouse gas traps in the atmosphere over a specific time period, relative to carbon dioxide. According to the Intergovernmental Panel on Climate Change (IPCC), methane has a GWP of approximately 28-36 over a 100-year timescale, while nitrous oxide has a GWP of around 265-298.

While methane and nitrous oxide have higher GWPs than carbon dioxide, it is important to consider their atmospheric lifetimes. Methane has a relatively short lifespan of around 12 years, meaning its warming effect dissipates more quickly. In contrast, nitrous oxide can persist in the atmosphere for over a century. Additionally, the total amount of methane and nitrous oxide emitted by human respiration is significantly lower compared to anthropogenic sources, such as agriculture, industry, and waste management.

To put the impact of human breathing into perspective, it is crucial to consider the broader sources of greenhouse gas emissions. The burning of fossil fuels, deforestation, industrial processes, and agricultural activities are responsible for the majority of greenhouse gas emissions globally. Addressing these significant contributors should remain the primary focus of climate change mitigation efforts.

Moreover, human breathing is a fundamental physiological process necessary for sustaining life. It would be impractical and unreasonable to consider eliminating or substantially reducing human exhalations as a viable mitigation strategy for global warming. Instead, efforts should concentrate on reducing emissions from anthropogenic activities that contribute to the bulk of greenhouse gas emissions.