'More knowledge is needed about the interaction between air quality and climate change’

Oration Prof. Guus Velders

The hole in the ozone layer, global warming, and air pollution are often considered to be three independent problems. But in his oration, Guus Velders, Professor of Air Quality and Climate Interactions, argues that this is anything but the case. “These themes are closely intertwined, so the policy processes for solving these problems should take that into consideration.”

In his research, physicist Guus Velders prefers not to focus on the most important greenhouse gas, CO2. Instead, he would rather look at gases such as methane and fluor gases, which Velders believes are much more interesting. Why? These gases not only influence climate change, but also directly or indirectly contribute to the damage or repair of the ozone level. Velders: “I am of the opinion that we should pay more attention to the interaction between climate change and damage to the ozone layer. On the one hand, to monitor its recovery, but also to take into consideration any effects that the implementation of climate measures would have on the ozone layer.”

Kigali climate accords

Velders, who is also affiliated with the RIVM (National Institute for Public Health and the Environment), is a leading authority in his field. In 2016, his calculations laid the foundations for the Kigali climate accords. There, the delegates decided after bitter negotiations to regulate the use of so-called HFCs (hydrofluorocarbons). HFCs replaced the use of CFCs, which degrade the ozone layer and were therefore prohibited years earlier. HFCs are not hazardous for the ozone layer, but they were projected to contribute dramatically to global warming in coming decades.

At the moment, I believe that we aren’t paying enough attention - including the politicians in The Hague.”

Vital to obtain more insight

“It is vital that we obtain more insight in the interaction between air quality and climate change. Only by doing so can we take measures that can address both problems. At the moment, I believe that we aren’t paying enough attention to that - including the politicians in The Hague.”

Air conditioning

It is precisely this interaction between damage to the ozone layer, climate change and air quality that interests Velders, and is what he will focus on for the foreseeable future. To continue with the example of the HFCs: these substances are currently used in air conditioners, but the Kigali climate summit will significantly reduce their use in the future. The industry is currently working on the development of alternatives for HFCs in air conditioners and other applications.

Good political decisions

“Without strong limits on HFC use, the climate could have warmed by an extra 0.5 degrees Celsius. That is a step forward, but if the restrictions on the use make air conditioners less energy-efficient, then the entire benefit is lost due to extra CO2 emissions. That shows how important it is to understand the interaction between climate change, air quality and other issues. It is my ambition to provide good information that politicians can use to make good political decisions.”

Read more: