Astrid Kiendler-Scharr and her team used a zeppelin to measure trace gases and particulate matter at high altitudes during the corona pandemic. An overview study combines such measurement campaigns from around the world.
What happens when mankind blows fewer pollutants into the air? Climate research typically relies on complex calculation models to answer this question. In the spring of 2020, all that changed.
The corona pandemic and its lockdowns did not only provide an unobstructed view of the Himalayas or surreal images of a deserted Venice. It also provided scientists with an as yet unique opportunity: they were able to observe live how the chemistry of the atmosphere changes when in fact fewer air pollutants are emitted. This in turn benefits the predictive power of the models.
Picture above: Astrid Kiendler-Scharr and her team used a zeppelin to measure trace gases and particulate matter at high altitudes during the corona pandemic. An overview study combines such measurement campaigns from around the world.
“The measures to contain the spread of SARS-CoV-2 have turned the world into a living lab for us,” confirms Prof. Astrid Kiendler-Scharr, who heads the Troposphere section at the Institute of Energy and Climate Research and recently became Chairwoman of the Board of the German Climate Consortium (DKK). “Researchers from around the world are measuring, comparing and evaluating how the composition of the air we breathe has changed during these lockdowns and what happens when lockdown restrictions are lifted again,” she adds.
In April 2021, an international team led by Jülich researchers presented a first comprehensive overview study, initially including data up to September 2020, of these worldwide measurement campaigns. “Other studies covering further periods will follow,” says Astrid Kiendler-Scharr. “It always takes a while to correctly evaluate and finally publish all the measurement data.” To speed up the transfer of knowledge, the Jülich team set up a website where research teams can continuously add measurement results.
A central – and not so surprising – result of the study: lockdowns, which were solely aimed at slowing down the spread of infections, also reduced atmospheric pollution in terms of nitrogen dioxide and particulate matter from man-made sources worldwide. “The stricter the restrictive measures, the stronger the effect,” explains the researcher. The values of ground-level ozone, on the other hand, which is harmful to living organisms if it is above a certain concentration, increased during this phase. “This is due to atmospheric chemical processes caused by less nitrogen oxides in the air,” she explains.
These data provide the basis for more accurate calculations on how air pollutants emitted by humans affect atmospheric chemistry and the Earth’s radiation budget. “By reducing emissions of short-lived climate pollutants such as aerosols, particulate matter, hydrocarbons, ozone and its precursors, as well as methane, we have an enormously important parameter on our hands to fulfil the Paris Climate Agreement. Rapid reductions in these pollutants leave an impact in a short period of time and can thus make a significant contribution to meeting the 1.5-degree target,” emphasizes Astrid Kiendler-Scharr. “Moreover, it is not only the climate that suffers from these short-lived air pollutants, but also people’s health, so a rapid reduction meets two major social challenges at once.”
Therefore, the publication of the chapter “Short-lived Climate Forcers” from the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) (in German) in August 2021 is highly anticipated. Astrid Kiendler-Scharr is the lead author of the chapter. In this role, together with an international team, she is currently reviewing and analysing the scientific literature on the topic that is available worldwide. “We will comment at great length on the details of our analyses in August,” she indicates.
COVID-19 Air Quality Data Collection
Interview with Astrid Kiendler-Scharr on progress in modern climate research and the importance of short-lived climate pollutants (in German):
The concentration of short-lived climate pollutants in the atmosphere decreases rapidly as soon as they are no longer emitted – within weeks or a few years, depending on the substance. The situation is different for the CO2 present in the atmosphere today. Without countermeasures, the current high concentration will persist for centuries, even if a zero-emissions quota is achieved.
Photos: Forschungszentrum Jülich/Ralf-Uwe Limbach, studio23/Shutterstock.com