London Low Emission Zone - Feasiblility Study

here is what i know.
I think that each country can only emit a certain amount of carbon credits,if they emit more they buy them off a country who emits less right?

Australia (where i live) wants to charge us for how much we emit each? so we can offset our emissions or buy more carbon credits?

is that the general theme?

The Rudd government wants to charge companies like electricity generating companies for producing electricity. These costs will be passed onto the consumer by increasing electricity prices.