The effects of COVID-19 in air pollution

We are all aware of the huge impact that COVID-19 pandemic will have in most of the population, both in an economic and social way. The final consequences of this situation are still unknown, but there are some ambits where a change of paradigm is starting to visualize, being the environmental one of the principals.

There have been a great number of pictures and videos where wildlife recovers some of the public spaces, that by now, were reserved for human use. Also, for the first time in decades, it is possible to have a clear vision in big cities. This huge reduction in pollution has been one of the few positive news that is leaving this situation. Industrial activity suspension, stagnation of individual mobility (both ground and air) and consumption reduction in many economic sectors are some of the factors that have directly contributed to this situation.

The areas which have experienced more critical changes are cities, as their activity has been considerably affected, especially in the mobility aspect. One fact that proves this statement is the great variation that NO2 has experienced (a polluting agent generated basically during the incomplete combustion that takes place in vehicle’s engine). In Catalonia, for instance, the effects have been quite remarkable, being the most drastic NO2 decrease associated with vastly populated urban zones.

Variation of NO2 concentration during the month of March 2020. Source: “Dades Obertes de Catalunya”

NOTE: This map reflects variation in NO2 concentration for the mean of the first half (pre-lockdown) in comparison with the second half (post-lockdown) of the month of March.

This information shows the huge participation that urban mobility has in atmospheric pollution, and once more is shown the importance to rethink the way this sector is conceived. The protagonist role that cities have nowadays will only increase in the coming years, and if a sustainable future is the objective, a transition is essential. Reinforcement of public transportation, urban planning optimization (in order to facilitate citizens access to services in short distances) and the encouraging of green technologies in vehicles are some of the basic measures that are starting to apply to improve.

Is it crucial to show though the difference between two phenomena that have similar origins but different consequences: atmospheric pollution and climate change. The first consists in the concentration of polluting agents in the air, which produce diseases and deteriorate land and water, meanwhile the second is a global change of climate behavior, basically caused by an anormal accumulation of greenhouse effect gases at the atmosphere. Climate change can have devastating consequences such as an elevation of sea level, increase of fires and natural disasters.

Both phenomena share the same origins, such as transportation or industrial sectors, but there are clear differences in geographical impact. Whereas atmospheric pollution is local, climate change is global. On the other hand, climate change effects are long term and greenhouse effect gases do not have to be the same that the ones that produce atmospheric pollution.

During this article, atmospheric pollution is the only issue that have been addressed, where improvements have been seen during the previous weeks, climate change though has long term consequences and prolonged measures are urgently needed to modify this worrying situation.


Martin Ferrer Escobar
Master’s Degree in Sustainability Science and Technology


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