Global warming - a gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect
Climate change - a long-term change in the average weather patterns that have come to define Earth's local, regional and global climates
Fossil fuels - Fossil fuels are hydrocarbons, primarily coal, fuel oil or natural gas, formed from the remains of dead plants and animals
Population growth - the increase in the number of individuals in a population
