The first warm days of the year are arriving earlier and earlier and are also getting warmer. That may be pleasant for people who are tired of the dreary winter. But it is also a result of climate change, with all its serious consequences.
I, too, have enjoyed the beautiful spring weather these days, because I simply function better in sunlight than in front of the stove or heat pump. But let the arrival of spring be a reason to take action against ignorance with renewed energy.

On page three of my newspaper on this beautiful day, there was also a report that climate change is now progressing so rapidly that the first warm day is arriving measurably earlier and the last one later and later. In a hundred years, the number of warm days in the Netherlands has risen from 60 to 70 to more than a hundred. Last year, there were even 112. According to Peter Siegmund, who has been a climate expert at the KNMI for almost forty years, we now have the kind of weather in spring that you used to have in Nice or Bordeaux.
I am glad that the reporting is not limited to a nice photo of a sun worshipper on the beach and a description of the beautiful weather. Fortunately, the newspaper also devotes a few sentences to scientists’ concerns about rising sea levels and to people for whom climate damage is already having much more serious consequences.
Action
With spring and warmer weather, demonstrating is becoming more appealing to me again. Last week, I stood outside the Aula of TUDelft, where I sometimes give lectures, during a protest. It was very windy and I found it bitterly cold. I admit it straight away, I quickly get too cold to stand there for long. Inside the Aula was the job fair, which unfortunately still featured a selection of fossil fuel companies that TU Delft simply allows to advertise their jobs, as if it were not all that urgent. But when I’m teaching, I look into the faces of twenty-year-olds. They really do know what’s going on. They are scientists. They know that you can’t just make CO2 disappear. I look into the eyes of people who are rightly afraid for their future.
My hope for the coming season of action is that we will be heard loud and clear if we speak out more often and in more places. Now that the sun has brought us out of our hibernation, let us work together to fulfil our academic duty to take action now that we see the world so threatened by disasters and injustice. The universities do not yet dare to take on that role. My hope is that, precisely when it is clear to us that politics and the media are not fulfilling their role sufficiently, we will be able to persuade the universities to speak out forcefully.
To achieve this, we will need the support of our administrators as well as the media, and we will have to seek out both the media and politicians. I realise that this will take a lot of time and effort, but I feel strengthened and motivated by the people at Scientist Rebellion. Since I signed up, I have met many fellow campaigners during protests and I am learning a lot from other SR members through the articles they share in our signal groups and even more through the conversations we have there.
Through our joint efforts, we are not only reaching the public, who are currently being kept fearful, ignorant and small by the Jack van Gelders of this world (the talk show host who said ‘they should just drive a tank over them’) and by politicians who are now hardly ever contradicted when they trivialise climate change, such as Caroline van der Plas with her statement ‘climate change is simply a thing of all times’.
This will also change how the media packages the climate message and how deceitful politicians are viewed. I hope for a snowball effect, but because spring is coming, I say ‘the sun will shine again’, hopefully also on the faces of my students.

Tjerk Oosterkamp (1972) is a professor of experimental physics at Leiden University. His focus is on experiments at extremely low temperatures to better understand quantum mechanics and gravity. Because of the seriousness of the climate situation, he has decided to take action. Tjerk is married and has four children.