• Wind (wind power) • Sun (solar energy) • Water (hydro-electric power) • Plant waste (biomass energy) • Hot springs or geysers (geothermal energy) • The sea (tidal energy)
called “greenhouse gases”, including
carbon dioxide, methane(甲烷, 沼气)
and water vapor.
• What do you think greenhouse gases do? They trap heat from the sun and therefore warm the earth.
What is the greenhouse
made and used for?
• How does it work?
The air inside is warm because
the glass traps the heat from the
sun and keeps it from escaping. This
Fossil fuels
What are fossil fuels?
• Ancient animal and plant material below the surface of the earth with a high carbon content, such as coal, oil and natural gas, which can be burnt to produce energy. Also known as nonrenewable energy because once they are used they have gone forever; they cannot be renewed.