Niall McCann talks to film-maker Tom Mustill about his passion to preserve the planet and his work with teenage environmentalist Greta Thunberg.
Forests - Deforestation and Desertification, Soil Erosion and Degradation, Ground Pollution, Sustainable Forest Management, Reforestation, National Parks
Energy - Fossil Fuels and Dirty Energy Renewable and Clean Energy, Nuclear Energy, Energy Efficiency and Conservation, Alternative Fuel Vehicles
