The corona crisis is causing a decrease in nitrogen dioxide pollution in. This is shown by data from the European earth observation satellite Sentinal-5P, which measures air pollution. Images from the satellite show that fewer extreme nitrogen dioxide levels have been reached in the atmosphere over Central Europe since the beginning of April. For example, there are hardly any large clouds of pollutants to be seen emanating from German metropolitan areas.
Josef Aschbacher, director for earth observation programs at the European space agency ESA, confirms the analysis of the WirtschaftsWoche. In its own investigations, the ESA also found that “in Germany, nitrogen dioxide pollution has decreased significantly”. This can be seen, for example, in the Ruhr area and on the border with Belgium and the Netherlands. However, the decline is not quite as strong as in some southern European metropolises. In Barcelona a reduction of at least 65 percent compared to the previous year was measured.
In order to obtain meaningful values, one has to observe the nitrogen dioxide pollution over several days, since this also depends on the weather. The temperature influences how quickly the gas in the air is broken down. Strong winds also carry it away and dilute it. “A snapshot taken on a day is therefore not very meaningful. But if you summarize the data from a period of ten cloud-free days, that is a good comparison value, ”says Aschbacher. Because nitrogen dioxide only has a short lifespan of a few hours, it is also relatively easy to relate to a source.
Nitrogen dioxide is mainly emitted by diesel vehicles and industry. Since mid-March, more and more companies have been sending their employees to the home office and shutting down their productions in order to reduce the risk of infection from the new corona virus. This means that the traffic on the streets is also visibly decreasing, as we have already shown.