103 DESCRIPTION OF THE ACTIVITY Stage 1: Watch a five-minute video in which physics researcher Otso Peräkylä and art expert Anne-Maria Pennonen share their thoughts of the work Kyrö Rapids (1854) by Finnish artist Werner Holmberg. https://vimeo.com/683219982/e8a9f2e147 Stage 2: Read the text below and watch the animation of the volcanic eruption cloud spreading to understand the main content of the lesson https://www.youtube.com/watch?v=K-4TB47N3_Y Based on what you see, prepare a poster, elevator pitch, or an opinion paper on why air pollution is not just a local problem, but a global challenge. Finnish researcher Markku Kulmala is a famous climate change researcher who has studied the effect of small particles on rainfall and the climate. Small particles are airborne particles smaller than 2.5 micrometers in size. They are naturally generated, for example, when the wind raises sand or tiny salt particles evaporate from the sea, and they act as condensation centers for the raindrops. The droplets begin to accumulate around them. Man-made air pollution has significantly increased the number of small particles. Polluted air has up to a thousand times more condensation cores than clean ocean air. The residence time of small particles in the atmosphere varies from a few days to a few months, during which time the particles do not have time to distribute evenly in the atmosphere. Still, air currents can carry small particles for thousands of miles. In the spring of 2020, the volcano Eyjafjallajökull erupted in Iceland. The ash rose to an altitude of eight kilometers, from which it was transported by air currents, especially in Europe. There was so much ash in the atmosphere that it threatened to clog the engines of the planes. As a result, air travel was canceled in Europe, and passengers around the world had to come up with other ways to return home. One volcanic