Climate change and air pollution: two problems that are interrelated.
Keywords: Short live climate pollutant (SLCP), Greenhouse Gases (GHGs), Radiative Forcing, Particulate Matter (PM) , Ozone.
Climate change and air pollution are two serious problems, as both affect the ecosystems, species and population. There are several articles discussing both problems and how these two are related, showing how the interaction occurs in different space and time scales, through various mechanisms (Fiore, Naik, & Leibensperger, 2015)
Historically, air pollution started with the discovery of fire and human exposure to the chemical species produced during biomass burning (combustion of wood and vegetation) in poorly ventilated locations where concentrations could reach levels that are harmful to human health (e.g., Hardy et al., 2012).
On the other hand, we have the climate which is defined as an average of the meteorological conditions in a period of at least 30 years. However in recent decades, climate has had more abrupt changes than in the geologic past.
The first relationship between both is basically the sources. During the 19th century, the Industrial Revolution led to the emission of significant amounts of air pollutants via the combustion of a variety of fossil fuels such as coal, oil, and gas (Seigneur, 2019 ). The sources from major air pollutants are also sources from Greenhouse Gases (GHGs) and are the principal cause of climate change. Some air pollutants that can affect the climate are called Short-Lived Climate Pollutants because they have atmospheric lifetimes of only days to a decade and a half. Some scientists agree with the idea that reducing SLCPs is critical for slowing the rate of climate change over the next several decades and for protecting the people and regions most vulnerable to near-term climate impacts (IGSD, 2013).
The Black Carbon (BC), methane, and tropospheric ozone are key constituents among the SLCPs. Once in the atmosphere, the emitted species have a variety of atmospheric properties that determine whether or not they have a direct or indirect influence on radiative forcing. This is critical because it modifies the energy balance of the earth’s system, inducing changes in the earth’s surface temperature in order to reestablish equilibrium (a balanced energy budget), being a potential climate change mechanism. For example, particulate matter has a direct influence on radiative forcing by scattering or absorbing incoming radiation, depending on the composition, as well as an adverse effect on human health (Von Schneidemesser et al., 2015).
After the Paris Agreement of COP21 in 2015, the combined mitigation strategy of GHGs and SLCP has become more important with a goal of the global surface air temperature not exceeding 2 °C and an effort goal of 1.5 °C relative to the pre-industrial era. The scientists study scenarios to reduce this and help solve both problems. Nakajima et. al. (2020) have found that it is possible to create a CO2 and SLCP reduction scenario that simultaneously mitigates the global warming part of climate change and the damages on health, agriculture, and water risk by a well-designed combination of various mitigation technologies.
Secondly, air quality depends steadily on meteorological conditions and therefore is sensitive to climate change. Altering the frequency, severity, and duration of heatwaves and precipitation due to climate change, would conduce pollutant accumulation. Ozone is one of the best examples. A number of modeling studies have investigated projected changes in future ozone concentrations considering different conditions to understand what the principal drivers in the ozone concentrations are. In many cases, future climate conditions will make it harder to achieve a given air quality goal, resulting in a need for greater emission reductions. Additionally, one of the main factors of forest fires is the weather (including temperature, relative humidity, wind speed and the amount and frequency of rainfall). Under a changing climate, this factor will be affected and extreme events could increase more than expected, having a significant impact on the risk of fire. With wildfires, emissions of pollutants increase mainly the concentrations of Particulate Matter (Von Schneidemesser et al., 2015).
In conclusion, to study and find how these problems are related is complicated. The pollutants have different chemistry processes, and the weather has variations, and to find out whether these are due to natural causes or to human activities is not a trivial work. However, both pollutants and climate interact and it is necessary to understand them and build knowledge, solutions and new policies with the aim of improving the air quality, fighting against climate change, reaching a healthy environment, and respecting human rights and the rights of other species. Every pollutant that we emit to the atmosphere affects and changes natural cycles and as a consequence our ecosystems.
Christian Seigneur (2019). Air pollution: Concepts, theory and applications, 1st Cambridge University press.
Fiore, A. M., Naik, V., & Leibensperger, E. M. (2015). Air quality and climate connections. Journal of the Air and Waste Management Association, 65(6), 645–685. https://doi.org/10.1080/10962247.2015.1040526
Hardy, K., S. Buckley, M.J. Collins, A. Estalrrich, D. Brothwell, L. Copeland, A. García-Tabernero, S. García-Vargas, M. de la Rasilla, C. Lalueza-Fox, R. Huguet, M. Bastir, D. Santamaria, M. Madella, J. Wilson, Á.F. Cortés, and A. Rosas,( 2012). Evidence for food, cooking, and medicinal plants in dental calculus, Naturwissenschaften, 99, 617.
IGSD. (2013). Primer on Short-Lived Climate Pollutants. Indiaenvironmentportal.Org.In, (February). Retrieved from http://www.indiaenvironmentportal.org.in/files/file/PrimeronShort-LivedClimatePollutants.pdf
Nakajima, T., Ohara, T., Masui, T., Takemura, T., Yoshimura, K., Goto, D., … Zhao, S. (2020). A development of reduction scenarios of the short-lived climate pollutants (SLCPs) for mitigating global warming and environmental problems. Progress in Earth and Planetary Science, 7(1), 1–21. https://doi.org/10.1186/s40645-020-00351-1
Von Schneidemesser, E., Monks, P. S., Allan, J. D., Bruhwiler, L., Forster, P., Fowler, D., Fowler, A., Morgan, W.T., Paasonen, P., Righi, M., Sinderarova, K., Sutton, Mark A, Sutton, M.A. (2015). Chemistry and the Linkages between Air Quality and Climate Change. Chemical Reviews, 115(10), 3856–3897. https://doi.org/10.1021/acs.chemrev.5b00089