Originally published on Comment is Free, John sets out how we could use the levers of the economy to shape a greener future.

Talk is cheap, and valued accordingly. At some point ministers will need to translate their climate rhetoric into the language of real change – money. Since 1997 the proportion of government revenues derived from green taxes has actually fallen. The cost of motoring (despite the tabloid headlines) has fallen by 13 per cent in real terms since 1997, while bus and coach fares have increased by 17 per cent above inflation.

For most of us, political speeches are a dull drone in the background while the message that always comes through loud and clear is spelt out in pounds and pence. If we're serious about confronting climate change – and everyone actively involved in the debate claims to be – then some taxes are going to have to rise.