Mobility restrictions to try to contain the COVID-19 pandemic in Spain have caused a drop in traffic which, in turn, has led to the collapse of air pollution to the lowest levels of the decade. Nitrogen dioxide (NO2) pollution has decreased by 38% between March and October, according to an analysis of official data carried out by Ecologistas en Acción.
The organization has reviewed the measurements of 129 stations distributed by 26 cities, all with more than 150,000 inhabitants and totaling 13.6 million people. The data accumulated between March and October leave a conclusion: reducing the volume of cars that circulate in cities improves the quality of the air that its citizens breathe. Only in the weeks of the first state of alarm (from March 14 to June 21) the levels of NO2 pollution – expelled mainly by the exhaust pipes – fell by 52% compared to the average of the last ten years on those same dates . If the series is extended to October 31, the reduction will be 38%. “It rebounds in the fall”, warn the ecologists who have verified how, with the return of the activity from September, the concentrations of this gas also rebound.
“Although the most abrupt changes were limited to the period between March and June, there have been mobility limitations in some part of the State practically at no time,” they explain. The reduction in urban traffic has been a direct consequence. “It drops radically when the first state of alarm goes into effect”, analyzes the work. The traffic crash During the house confinement of March and April, it was noted in a almost immediate in contamination rates that already fell by half at the end of the first fortnight of state of alarm.
But, as the restrictions were lifted with the de-escalation phases and the so-called new normal, traffic returned to the cities. They especially noticed it in Donostia, Valencia or Cádiz, where the summer traffic data in 2020 “is very similar to the previous year”, according to an index of daily traffic jams collected in Web traffic congestion index. Madrid is the city with the most difference in the volume of cars between 2020 and 2019.
“It is an unprecedented improvement. With levels below legal thresholds and those recommended by the World Health Organization [más estrictos]”, summary. In Vigo, Palma, Alicante, Valencia, Santander or A Coruña, the average drop is almost 50%. In Cádiz and Málaga they remained at 23%. Madrid and Barcelona, both the focus of a European Commission lawsuit against Spain before the European Court of Justice for excess pollution, 42% less nitrogen dioxide has been registered than the 2010-2019 average. Zaragoza has improved by 30% and Seville by 36%, according to the situation cards of each city.
The situation now verified in Spain by the environmental organization has been evident throughout the year. In 2020, evidence has accumulated on the direct impact that urban traffic based on fossil fuel cars has on poor environmental quality and its repercussions on people’s health. Furthermore, NO2 is a necessary gas (a precursor) so that, when receiving solar radiation in other areas, tropospheric ozone is produced. This powerful oxidant with proven harmful effects on health has also dropped in 2020. Less nitrogen dioxide means less ozone in summer.
Thus, last May, the greenhouse gas emissions that warm the planet in Spain had fallen by 32% compared to 2019. The main source of the reduction? Transport, as explained by a team of researchers from the University of East Anglia (United Kingdom). The scientists claimed that the drastic changes brought about by the pandemic were undesirable, but, at the same time, they admitted that demonstrated that “lasting change, especially in mobility”.
With these data, Ecologistas en Acción stresses that “the structural reduction of motorized traffic and changes in mobility guidelines are the best tool to reduce pollution.”