Aerosols cause health problems, are harmful to nature and play a role in climate change. TNO’s Martijn Schaap has performed research on aerosols for many years. He will build on the acquired knowledge as newly endowed professor at the Freie Universität Berlin.
Congratulations on your appointment. Can I call you Martijn or is it now Herr Professor Doktor?
“No, no, stick to Martijn please. When I give a lecture in Berlin I also ask the students to address me by my first name. That’s quite unusual in Germany where things are a bit more formal. But they’re getting used to it.”
Aerosols? What are they actually?
“Aerosols are tiny particles suspended in air, which are also known as particulate matter. Soot and smoke are examples. Aerosols can be transported over large distances in the atmosphere.”
Why should we want to know more about them?
“Aerosols are so small that you can hardly see them if at all, yet they are very significant. For instance, they may cause lung diseases. Exposure to aerosols is believed to reduce the life expectancy of people in the Netherlands by 6 to 12 months. In addition, aerosols formed from ammonia from intensive husbandry are one of the main causes of a decline in biodiversity. Moreover, they have an impact on global warming. On the one hand, they cause heat retention while, on the other hand, they reflect solar radiation and, therefore, cool. Putting the two together results in a nett cooling effect on climate.”
"Aerosols are so small that you can hardly see them if at all, yet they are very significant"
So aerosols have their good side, too?
“I guess you could say that, yes. But if you weigh up the positive and the negative effects, the negative comes out on top.”
What will be the subject of your research in Berlin?
“We know little about the origin, fate and impacts of aerosols. The origin of a third of all aerosols is even unknown. The expertise on meteorology and remote sensing at the Freie Universität Berlin complements my own activities. Located centrally in Europe, Berlin provides an interesting case. The senate of Berlin is interested to learn how to develop strategies to improve the air quality in the city. TNO has a long lasting collaboration with the Freie Universität Berlin. My TNO colleague Peter Builtjes is Honorary Professor at the department where I start to work. TNO also has good contacts in Belgium and at the European Commission.”
Where is it that TNO is at the forefront of research into aerosols?
“We have our own model system, which we can use to study the formation and fate of aerosols. The model system builds on, among other things, the extensive TNO expertise on industrial, traffic and agricultural emissions. Other knowledge institutes also use this expertise in their model systems.”
What does that research lead to?
“We can forecast aerosol pollution a few days ahead and thus warn the public, especially people in high-risk groups like asthma patients, who can then take this into account.”
“Our model system also enables us to quantify the effects of (potential) policy measures so that we can advise the authorities if they want to get to grips with pollution caused by aerosols. An example is incentives for electric driving. This would diminish the exhaust emissions from traffic, although that’s not the whole solution. The electricity still has to be generated and preferably in a way that causes the least possible pollution. We can advise on that.”
Aerosols have a big impact on our lives but you hear very little about them. Why is that?
“There is indeed little sense of urgency. I compare it with traffic safety. When accidents occur regularly at a particular crossroad, it gets noticed and measures are taken. The harm caused by aerosols is not so glaringly obvious, but it is much greater in the long run. In my role as a professor, I hope to help get the issue higher up the societal agenda.”
A deceptive problem then. Where is it visible?
“Last year in Paris the atmospheric pollution became so serious that road traffic had to be reduced. On alternating days only cars with an even or uneven number in their licence plate were allowed on the road. Our model system allows us to address the root cause. A significant percentage of the pollution originated from the Netherlands and Belgium, from agriculture and transport. And if you know that, then you can target the right solutions.”
"Last year the atmospheric pollution became so serious that road traffic had to be reduced"
Will you continue working for TNO?
“My appointment in Berlin is for one day a week. The rest of the time I will continue working at TNO, which can also benefit from my appointment. We have already been collaborating a lot with German institutes and I hope this will intensify these relationships.”
And how will you travel there and back?
“What do you think? By train, of course.”
First a celebration?
“Already happened. As soon as I got the news of my appointment, the champagne was popped.”