Is the greenhouse effect caused naturally?
There are greenhouse effects caused both naturally, and
exacerbated by man's activities.
Earth's natural greenhouse effect is caused mostly by water
vapour, and to a much smaller degree, by carbon dioxide, methane,
and a few other minor gases. These factors help keep the Earth warm
The "unnatural" (or enhanced) greenhouse effect is what results
from the burning of fossil fuels and deforestation. Fossil fuels
release extra carbon when they are burnt, and forests are no longer
there to absorb and store carbon.