The 21'st century is the era when the treat from climate change creates a real ecological awareness (or at least it should). The word green is now a synonym for the environmentally friendly and the nature least damaging devices, processes, technologies. In the motoring world the green vehicles are the ones with minimal tailpipe emissions, in particular the CO2 emissions. On the opposing ends are the gas guzzlers, i.e. vehicles that are particularly inefficient for their given size. All new cars are now required to officially disclose the CO2 emission figure in the spec. Although comparing CO2 emission figures of all electric cars to their conventionally fuelled counterparts is little like comparing apples and oranges, it is still possible. Hence the g/km figure for electric cars appear in their spec, even those cars don't emit any CO2 at tailpipe. On the same basis the MPG figure is calculated, even the EV cars don't use any conventional fuel that could be measured by volume (in gallons). To calculate the average amount of CO2 released to the atmosphere for the electric vehicle to cover a certain distance, all the different stages of electricity production and distribution is taken into the account. For a good example of such calculation look under the Petroleum-equivalent efficiency section for Tesla Roadster.

Global warming is already happening, and to mitigate it various green objectives are outlined by world top scientists.
To meet these green objectives the British government is taking measures meant to reward all who are going green or shell we say punish those who are not.
As far as motoring goes the fuel economy (efficiency) is the centre point, and the following green measures are already affecting our everyday life. Unfortunately due to the economic crisis all that may not be quite enough of stimulus to introduce reduction in car emissions at the rate needed to prevent global warming.

We also mustn't forget that by burning less fuel we are not just saving on our pocket, but also by creating less heat pollution, we are helping to save the planet.

In the league table the UK's emissions are down 8% on 1992, as a result UK has moved from 7th to 10th place since 1992.

1) London Congestion Charge was £8, then £10 and now is £11.50 per day. Alternative fuel vehicles were exempt but not any more. All who drive into central London every day should get one of these and save £1600 per year (based on 200 visits per year):
- Electric Cars
- Hybrid Cars are exempt only if meet the criteria bellow, otherwise are not
- Alternative Fuel Cars are exempt only if meet the criteria bellow, otherwise are not
- All Cars which emit 75g/km or less of carbon dioxide and meet the Euro 5 standard

2) The VED bands (road tax bands) are prompting us to buy new vehicles with low CO2 emissions (luckily those vehicles are also the most efficient ones). At the moment there are only handful of cars available on the market in the road tax free in the sub-75g/km CO2 emissions band (band A), and none of them are with a conventional petrol or diesel engine.

3) In 2010 Chancellor introduced the £2,000 UK Car Scrappage Scheme, a discount for all who trade in a 10 year old plus vehicle. That was the latest significant measure to slash the CO2 emissions on the road.

4) Now that the petrol fuel prices are dangerously approaching the diesel fuel prices, and since literally all the cars in the lowest VED bands are diesel cars (except for Electric and Hybrids), this latest rise in petrol prices just makes these supper economical diesel cars more attractive.
Well that was a while ago, nowadays we have a fair number of petrol cars in lowest VED bands, but supper efficient diesel cars still dominate the area.

One car to definitely watch out right now is the Audi A1 e-tron concept city car. Since 2010 Audi scrapped the initial A1 and A2 e-tron concept electric city cars, but is now set to go ahead and manufacture the second A1 e-tron concept electric city car instead. This sporty little fellow can apparently do 0-62mph in 9.0s and in reality it feels even quicker. Described as a 'dual-mode' hybrid it will be possible to run it up to 81mph in pure electric mode, something that more conventional plug-in hybrids can't do. Additionally its relatively simple engine and electric motor layout coupled with a single-speed transmission is expected to be less expensive to manufacture and maintain than today’s production hybrids and at the same time this car feels more refined compared to them. That is quite something and such 'dual-mode' hybrid design despite its lower cost and simplicity appears to be technicly superior to Ampera's / Volt’s range-extender too. Audi being a luxury car manufacturer won't hesitate to squeeze as much as goodies as they can into this little city car, so one can expect that BMW might loose out a bit from the territory it dominated until now by its Mini E.

Another green proposition already available since 2007 is the Flexible Fuel Vehicles (FFV), that can run on bioethanol or petrol or any mix of the two in the same fuel tank. Their carbon emission figures may not seem as too impressive, but that is almost cancelled out by carbon emissions absorbed by the crops as they grow. For now bioethanol is currently only available at some Morrisons supermarkets, and we can only hope that in 2013 further bioethanol filling stations will be introduced nationwide. The bioethanol prices probably won't rise or hopefully could even come down (unlike their fossil fuel counterparts).

Alternatively London city residents can now do without a car, since the Pay-as-you-go car rental scheme operated by zipcar, offers a cost effective and Low emissions motoring alternative to car ownership. The private membership is £59.50 per year, while the hourly rental rate starts from £5/hour and £49/day during the week and £6/hour and £55/day on weekends.