is the long-term heating of Earth's climate system observed since the pre-industrial period (between 1850 and 1900) due to human activities.
global warming
is a fuel formed by natural processes, such as anaerobic decomposition of buried dead organisms, containing organic molecules originating in ancient photosynthesis that release energy in combustion.
fossil fuels
is air pollution that reduces visibility.
smog
is the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be without this atmosphere.
greenhouse effect
is useful energy that is collected from such resources, which are naturally replenished on a human timescale, including carbon neutral sources like sunlight, wind, rain, tides, waves, and geothermal heat.
renewable