The video discusses the impact of light pollution on nocturnal animals and ecosystems due to excessive and unnecessary lighting at night. Cooler lights (below 3000 degrees Kelvin) are less harmful to insects and other animals compared to brighter, colder lights (above 5000 degrees Kelvin). In the central German town of Fulda, Sabina Frunk, a dark sky part coordinator, noticed that trees were retaining their leaves in November due to light pollution. She advocated for changes in street lamps to become the first official dark sky city in Germany. People in Fulda are now aware of light pollution and join Sabina in advocating for "Lights out, stars on" and "Lights out, night on."