5.4 Why is the climate changing?

Question 1

Greenhouse gas

Answer 1

Atmospheric gas that prevents
infrared radiation escaping into space. Important
greenhouse gases include carbon dioxide and
methane. As a result of human activity, more of
these gases are being produced. Since they stop
the escape of infrared radiation, they have been
linked to rising temperatures and global
warming.

Question 2

Greenhouse effect

Answer 2

Some of the radiation
reaching the Earth from the Sun has a short
wavelength. It is reflected by the surface of the
Earth as infrared radiation, which has a longer
wavelength. Some of this infrared radiation is
absorbed by greenhouse gases in the
atmosphere. The atmosphere is warmed and this
keeps the Earth’s temperature high enough to
support life. This process is similar to the way in
which a greenhouse provides a warm
environment for growing plants, so it is called
the greenhouse effect.