11-year-old Felix Finkbeiner from Germany, inspired by Wangari Maathai, plants millions of trees. We learn from him how trees take up CO2 and help mitigate climate change. Students can research which tree species take up the most CO2. They can also calculate how much a tree takes up as it grows by measuring the circumference of its trunk. Plant trees in your schoolyard and community and track the growth of each tree (height and trunk diameter DBH) for an LTER (Long Term Research project) and carbon sequestration over time.