Don't think petrol, think electric, that's the message coming from the Paris Auto Show where carmakers are falling over themselves to show off their green credentials and their plans for zero emission electric cars.

From all-electric sports cars to cute little superminis with solar batteries in the roof, all the manufacturers want a piece of the action. If the rumours are to be believed we could even be seeing Audi and BMW electric cars on our roads some day.

It all sounds magnifique, doesn't it?

Now I'm not completely knocking the electric car because it will have an important role to play in the move away from the combustion engine. Along with increased public transport and all the other ways you can think of for getting around and helping the planet out. (And you can call me a revolutionary if you like, but for short journeys you could always hop on a bike or walk.)

Even if they turn out not to be the holy grail of new car technology, many of these
electric cars will have lower emissions, and that's a good thing. But zero CO2 emissions? I hope you're not buying that idea.

It's true that nothing much will be coming out of the exhaust pipe, but when you think about where all that extra electricity is going to come from all that greenness might just turn out to be un peu overdone.

Let's look at the facts. In 2005, 35% of electricity generated came from nuclear sources.

That's more than a third of the electricity in Europe.

© Greenpeace / Jesse Anttila

And we all know what happens when you generate nuclear energy. I wasn't quite thinking of Chernobyl, but that is one of the things. And if you think that's all in the past, it's been going on this year, in Belgium, in France and with safety issues in Finland where a new reactor is being built.

The other problem is that you get truck loads of radioactive waste that no one has figured out a way to deal with.

So what about the other 65%?

© Greenpeace

Well, the bad worse news is that only 14% of electricity generated in Europe comes from renewable sources.

So that means that your brand new electric car is 35% nuclear, 51% CO2 emitting and only 14% green.

And what happens if electric cars take off in a big way? Pretty soon, we'd need to generate a whole lot more electricity.

© Greenpeace / Steve Morgan
But don't worry Greenpeace has a revolutionary answer. An energy [r]evolution that would enable us to meet 50% of the world's total energy demand, through a massive up scaling of clean energy, by a combination of renewable energy and energy efficiency.

And before you ask what about all the increasing population levels we can expect in the future, economic growth (assuming the world can gets out of the mess its in now) and so on? Well the report takes that into account, and according to the predictions we'll be able to provide energy to an additional 2 billion people.

And I haven't forgotten about all those electric cars either. I'll give you a scoop about the new version of the report, which isn't launched until the end of the month. It will show you how even with a shift of up to 50% of the world's cars to electricity and the increased energy needs can still could be met by renewables and improving technologies.

If you want to get stuck into the details, you'll have to hang on a few days, but I'll let you know where to find the report as soon as I can.