By reducing the recommended heights, existing laws come under pressure – or at least are being questioned. While the European Air Pollution Control Directive largely complied with the previous WHO recommendations from 2005, gaps are now apparent. The EU has already announced a revision and launched the corresponding consultation. Read more
In 2019, the UN decided to declare September 7 the “International Day of Clean Air for Blue Skies”. With the Corona-related lockdown, images went around the world showing blue skies where visibility is otherwise severely restricted by polluted air. We have also published a number of articles on this topic, whereby not only the concrete effects on cities were examined, but also the effects on health were questioned. Read more here.
This year, the UN is putting the day under the motto “Healthy Air, Healthy Planet” and thus combines two important aspects: Polluted air is a problem for health AND for the climate.
Some air pollutants, such as black carbon, methane and ground-level ozone, are also short-lived climate pollutants. On the one hand, they are responsible for a significant proportion of deaths caused by air pollution, as well as for the effects on plants and thus food security. On the other hand, about half of climate change is caused by short-lived climate pollutants. So that their reduction will have simultaneous benefits for the climate.
Here, too, silos must be torn down in thinking: It is not a question of taking care of air quality OR climate protection – often unfortunately only understood as CO2 reduction – but of tackling both together. This is not only a global challenge that can only be solved by local approaches but also offers great opportunities and synergy effects thanks to modern technologies.
Today is “Earth Day”: Time to recall the ambitious goals we have for the reduction of greenhouse gases. It is good to see how prominently the topic of CO2 footprint is covered in the media and in public discussions. In addition, we need to be aware that Black Carbon and tropospheric Ozone, which are usually recognized as air pollutants, are also considered climate pollutants. They belong to the group of “Short-Lived-Climate Pollutants” (SLCPs). Why are they called “short-lived”? Because their atmospheric lifetime is a fraction of that of CO2.
This is both a threat and an opportunity: measures curbing SLCPs generate their impact within weeks, while Methane and CO2 abatement measures require decades, if not centuries. So, by focusing on mitigating air pollution we are tackling a perpetrator that is harming both our health AND our climate. In fact, according to the WHO and UNEP, climate change mitigation will only be possible when SLCPs and CO2 are addressed simultaneously.
A deeper analysis for Munich
The COVID-19 pandemic has infected about 13 million people and claimed more than 550 thousand deaths worldwide by 14 July 2020. It has been reported in research that high air pollution may be “one of the most important contributors to deaths from COVID-19”. Studies show a positive correlation between particulate matter and nitrogen dioxide to health damage and, more specifically, to diseases related to the lungs like pneumonia, which makes people suffering from these ailments more susceptible to COVID 19. On the other hand, due to the lockdown measures, significant improvement in air quality has been witnessed. Read more
Air quality management – a fascinating lineage
I grew up in Cairo. A city that shows all the typical traits of an emerging economy when it comes to air quality and health. I grew up in a household of doctors, who spent their lifetime researching the delicate relationship between the air we breathe and our health. Here is a paper co-written by my dad for The Lancet Journal on the “Effect of nitrogen dioxide and sulfur dioxide on airway response of mild asthmatic patients to allergen inhalation” written back in 1998. So imagine you grow up seeing and hearing about the “Black Cloud” of Cairo and the rise of patient visits in my parents’ clinic around the dinner table. Or discussions on best treatment options for patients during the long drives towards the Egyptian Red Sea coast with its windy fresh air. Thus, I always understood the topic of air pollution within a context – the context of bad health indicators, exacerbated symptoms, increased healthcare expenditures and overall reduced life quality. Read more
In general all graphs show that the mean NO2 concentration after the lockdown date has decreased – at some stations the effect is larger than at others. Concentration peaks with similar amplitudes, compared to before the lockdown, persist. The overall patterns would require a more detailed analysis of the locations e.g. considering mobility behaviour.
Cities worldwide have been imposing lockdowns due to coronavirus, leading to traffic reductions and related to that, less NO2 pollution. The strength of the effect is not the same everywhere, being dependent on a number of variables, such as pollution levels and amount of traffic before the lockdown at the particular location, fleet composition, weather conditions and topography and urban architecture. Furthermore, the measures defining the “lockdown” were not the same everywhere and were also implemented with different levels of rigour. Without analyzing in-depth the factors at play at different places across the world, here just a few examples of what the change in NO2 pollution looked like in a few cities:
I have recently heard people uttering disappointment regarding the rather small effect they have observed at official measurement stations in Munich during the time of the lockdown due to the coronavirus. Looking at the raw hourly measurement traces at different locations in and around Munich, we can see a very clear drop during the initial phase of the lockdown, with concentrations coming up again after that. So we decided to take a deeper look. We considered impacts from weather conditions, season-specific influences as well as mobility behaviour. Read more
Although measures to curb the Corona virus have (almost) brought many polluters to a standstill, the effects on the trends from measurements are not as obviously visible as some may have expected. In an interview with the Süddeutsche Zeitung, Dr. Birgit Fullerton, Head of Data Sience of Hawa Dawa, mentions possible reasons why the effects of the lock-down are not more clearly and sustainably recognizable in the air pollutant concentration in the area of Munich Airport (Süddeutsche Zeitung “At the airport you can hear the sparrows chirping”). Read more
While it is too early to clearly analyse the factors that affect survival rates of COVID-19 in different regions of the world, there is a fair amount of evidence that promotes the hypothesis that air pollution levels could play a significant role. Read more