I’ve just found this handy Greenhouse Gas Equivalence calculator on the US environmental protection agency website. Because you can’t see CO2 emissions, it can be hard to visualise what effect we’re having on the environment every time we take to the roads in our cars. But with this calculator you can enter an amount of CO2 and work out what it means in barrels of oil consumed, energy use in your home or emissions from a coal fired power plant. And as I wrote about Kingsnorth recently, I thought I’d used that comparison.

It turns out that car drivers in the UK cover a staggering 404 billion kilometres each year.

So what are the CO2 emissions on that and what could be saved when the EU cars legislation takes effect?

Last year average CO2 emissions were 158g/km CO2 per kilometre travelled. So in a year, the citizens of the UK would run up over 63 million tons of CO2 emissions just from driving. (But there are a couple of things to bear in mind here - we don’t all drive new cars, and the figure of 158g reached by measurements taken under test conditions. Out on the road emissions will be much higher.)

I put 63 million tons into the handy greenhouse gas equivalence calculator, and guess what I found?

It works out at the annual CO2 emissions from 14 coal fired power stations.

So cars on the road in the UK today are responsible for as much CO2 as almost two thirds of all the coal fired power stations in the country. I was shocked by that. No wonder car travel is high up the EU agenda for reducing CO2 emissions.

Now I’m not saying if we drove less we could shut down the power stations, because that’s not true, and I’m definitely not saying that if we made savings on car emissions we could build more power stations because that wouldn’t help at all. And as for nuclear – don’t get me started on that. What we’re talking about here is doing something to try to prevent more climate change by getting CO2 emissions down. And if we think about it in terms of power stations, it’s not hard to see the impact this will have on our lives and those of future generations.

So if the EU brings in a law to reduce the average CO2 emissions, when all the cars on the road were replaced with ones meeting the new target, annual emissions would go down by 10 metric tons.

And that would save the annual emissions from 2 power stations.

It’s important to note that I’m not suggesting everyone rushes out and buys a new car, but when cars are replaced it’s an opportunity to make significant savings on CO2 emissions.

But this is just what the car industry wants to settle for. I’m sure with a little more effort we could save another power station’s worth of emissions.

The original proposal from the EU commission was for an average emission rate on new cars to be capped at 120g/km. That would mean bringing down the total CO2 emissions in the UK by around 15 million tons.

If that sounds like quite a big reduction, it is and it would save us almost another 2 power stations.

And remember the technology to do this is already out there – Greenpeace have proved that with their low emissions convoy.