City Car Club compiled the figures after an exhaustive search on celebrities and their cars, the figures an average of the relevant star's fleet.

1: Jenson Button - 383.1g/km
Putting his Bugatti Veyron - 574g/km on its own - up for sale will help his combined CO2 output a tad but the current Formula 1 champion's taste for fast cars off the track as well as on puts him in a clear number one spot. Blame a love of Ferraris as the main reason, an Enzo and F430 Spider at 420g/km among those he's owned. Add in all that jetting around to races and the McLaren driver's carbon footprint must be truly epic.

2: Jay Kay - 379.3g/km
Infamous petrolhead Jay Kay has a serious fleet of fast machines which puts him into second place on this list. His formidable collection of classic sports cars will all be high polluters thanks to their old-tech engines but his modern cars aren't much better, Mercedes, Aston Martin and Lamborghini all on the high polluting fleet.

3: Simon Cowell - 376.8g/km
It's somewhat inevitable that sharp-tongued music mogul Cowell has no time whatsoever for tree hugging sensibilities when it comes to his car choices. And it says something that a 400g/km Lamborghini Gallardo is one of the greener cars he's owned. A Ferrari F430 at 420g/km and Bentley Azure at 465g/km aren't even the worst offenders. No, that's his Bugatti Veyron, at 574g/km by far the most polluting car you can currently buy.

4: David Beckham - 360.8g/km
Life in LA among the Prius loving masses obviously hasn't influenced David Beckham too much, his taste for cars the very personification of footballer bling where eco posturing isn't the done thing. The inevitable Bentley Continentals contribute to his high score on the CO2 scale, a Ferrari 550 Maranello and love of American SUVs like the Hummer and Cadillac Escalade sealing it.

5: Ronaldo - 358.6g/km
Whether or not he's replaced the 490g/km Ferrari 599 he famously wrecked in a tunnel under Manchester airport Ronaldo's taste for exotica marks him out as our fifth most polluting celeb.</p> <p>Another footballer's favourite, the Bentley Continental GT, is an additional big polluter at 396g/km, a 377g/km Rolls Royce Phantom and smattering of Porsches only adding to his average figure.

6: Rio Ferdinand - 347g/km
Yet another footballer with a taste for the blingier, bigger engined end of the motoring spectrum Rio Ferdinand's Bentley Arnage manages a truly epic 465g/km of CO2 making it the fifth most polluting car you can buy in the UK. His Aston Martin Vanquish isn't much better, his daily runarounds of a BMW X5 and Porsche Cayenne hardly Prius-like in their CO2 outputs and contributing to an epic overall average.

7: Gordon Ramsay - 341.3g/km
You wouldn't expect Gordon Ramsay to apologise for anything, let alone the fact his fleet of cars has an impressive collective CO2 rating of 341g/km. It would be a brave eco warrior who tackles him on this too. Streams of swearing aren't the only thing Ramsay emits in epic quantities then, his well documented love of fast cars - Ferraris in particular - contributing to his anti-eco stance. His F430 accounts for 420g/km on its own.

8: Richard Hammond - 297g/km
The second Top Gear presenter to feature in this eco hall of shame, Richard Hammond's love of old muscle cars helps elevate him above fellow star Jeremy Clarkson, which will no doubt cheer Hammond. His passion for Morgans doesn't help either, though 265g/km for the 4.4-litre V8 powered Aeromax isn't actually too bad given the performance. Performance that got him into a bit of fix last year when he pranged it.

9: Steven Gerrard - 283.7g/km
Hollywood stars and politicians may have jumped on the Prius/hybrid eco bandwagon but footballers remain unabashed fans of high polluting SUVs and supercars, with four of them in this top 10 alone.</p> <p>Steven Gerrard's love of blingy cars like Bentley Continentals certainly contributes to his average CO2, though his tendency towards BMW products - like the X5, X6 and a Mini - and their typically low CO2 does help cut his carbon footprint somewhat.

10: Jeremy Clarkson - 274.3 g/km
Ever the unapologetic petrolhead, the fact Clarkson only makes 10th on this list will probably cause him some disappointment. Indeed, in this company 274g/km makes him positively a tree-hugger. Even a taste for V8-powered AMGs can't push his average up to the point a truly committed champion for high performance cars could rightly take pride for. Maybe his proven love of Volvo XC90s indicates Clarkson's secret Birkenstock-wearing eco warrior credentials.

Source: MSN Cars