Direct Health Effects of Greenhouse Gases
The Greenhouse Effect. Source: World101
Greenhouse gases are well known for their role in driving climate change. By trapping heat from the sun in the atmosphere, they increase the global average temperature and change the Earth’s climate. Climate change is responsible for causing various health hazards, such as extreme heat, an increased severity of wildfires and floods, and more incidences of natural disasters. However, greenhouse gases also impact air quality and the safety of our environment in other, more direct ways.
Although methane is emitted naturally, most emissions come from man-made sources like agriculture, landfills, and oil and natural gas systems. As the second most emitted greenhouse gas, the prevalence of methane is also a health concern due to its role in forming ground-level ozone. While ozone up in the stratosphere helps to block harmful UV rays, its presence at the ground level affects air quality and is a main factor in the production of smog. Breathing in ozone impairs human health by negatively impacting the respiratory and cardiovascular systems.
“Overview of the main natural and anthropogenic sources and sinks for CH4.” Source: C3S/CAMS/ECMWF.
Unlike methane, fluorinated gases, or F-gases, are a set of man-made greenhouse gases that are used in industrial processes, like refrigeration. Common F-gases, including HFCs and HFOs, are classified as per- and polyfluoroalkyl (PFAS) substances, or “forever chemicals”: a set of over 4,700 chemicals that pose health concerns due to their strong tendency to persist and accumulate in the environment and the human body. There is still much research to be done to understand PFAS risks. However, as certain PFAS have been linked to various health impacts like liver damage and cancer, scientists and governments are also concerned about the potential risks of other PFAS.
Compared to F-gases and methane, carbon dioxide takes the lead in terms of emissions, making up 65% of all greenhouse gas emissions globally. The burning of fossil fuels and other biological materials is the main cause behind the rising levels of carbon dioxide. However, as a natural constituent of our atmosphere, carbon dioxide only makes up about 0.04% by volume, and it disperses well, which means that its concentration does not vary much outside. In indoor environments, carbon dioxide may only become hazardous at high levels, though these are uncommon. Therefore, carbon dioxide’s impact on health is mainly limited to its global warming potential.
“Overview of the main natural and anthropogenic sources and sinks for CO2.” Source: C3S/CAMS/ECMWF.
According to the World Health Organization (WHO), climate change is today’s greatest threat to human health. Although most greenhouse gases occur naturally in the atmosphere, their elevated presence caused by human emissions is unnatural and disruptive to environmental processes. It is therefore important to reduce greenhouse gas emissions both due to their global warming potential as well as their direct impacts on the safety of our environment.
