Environmental protection

atmosphere: Oxygen, Hydrogen, Nitrogen, Carbon dioxide, Carbon monoxide, Ozone, sulphur monoxide

pollution: air pollution, acid rain, contaminated water, pollutant, contaminant, chemicals, toxic waste

Geographical: soil erosion, desertification, drought, floods, overfishing, over-felling, deforestation

energy: fossil fuels, coal, gas, petroleum, solar, tide, wind power, nuclear, marsh gas, methane, biogas

recycling: plastic, paper, glass, bottle tops, ink cartridges, spare parts/components