The Government's planning to declare a climate change emergency - well, for the drivers of gas-guzzling, smoke-belching, grunt machines that is.

Cycling supremo Julie Anne Genter's leading the charge, telling us that most of us want to buy a car that's good for the environment. Trouble is that most of us tend to hang on to our rust buckets for close to 20 years and the exhaust fumes spew out 20 per cent of our greenhouse gas emissions, the fastest growing source by far.

So surely cleaning up the fleet's a no-brainer and it seems they've come up with a pretty good way to do it but it'll take time. It's a case of the petrolheads paying for the fuel-efficient goodies.

They're looking at two ways of doing it, through a Clean Car Discount and a Clean Car Standard.

The standard will involve a set of emission targets which will require vehicle importers to bring in cleaner cars, both new and used. By 2021 vehicle dealers will have report the emissions of the vehicles they import, getting stricter over the following four years.

The Clean Car Discount starts in the same year and if you buy a new imported zero emission car, such as electric, you'll get a discount of up to eight grand. So who pays? Well if you're a baddie and buy the new gas-guzzler that emits a higher level of CO2 then you'll pay a fee of up to three grand. There are lesser discounts and penalties for used imports.

But if you're a fat cat and buy a growler for over $80,000 you won't be in line for a discount, because obviously you can afford it. Pity, because it essentially limits your choice to the likes of a Toyota Prius rather than maybe a Tesla or a BMW.

Before you start graunching your gears, yelling "on yer bike" at Genter, relax. If you're buying and selling an old banger already registered here then you'll be exempt from penalty and discount regimes - which means more than 70 per cent of transactions will be unaffected.

That's why achieving a more environmentally friendly fleet is going to take a long time.

If we want to achieve a mainly electric fleet in just over 30 years' time, almost all new vehicles would have to be electric by the early 2030s.

The Transport Ministry predicts that without government intervention or incentives only 40 per cent of vehicles coming into the country would be electric in just over 10 years' time.

At least it's a start - and let's be honest, few of us would regret reversing away from the petrol pump for good.