What is pollution?
Mostly it's smoke and gases which come from burning fuels to make energy. But it isnít always obvious.
Some of the polluting gases stink - yuk! That's obvious!
Some pollution is clouds of black soot particles.
Some pollutants are deadly poisonous and can kill people.
But the main pollution is that colourless heavy gas which just about everyone has heard of: carbon dioxide (often shortened to CO2). This gas has no smell and people use it to put the fizz in fizzy drinks. It is also a 'greenhouse' gas... and that spells trouble for the planet's climate. Most CO2 comes from people burning fossil fuels and destroying forests.