The Dakar rally gets under way in South America this weekend, amid concern about the potential damage that the 8,400-kilometre (5,200-mile) trek through Peru and Chile could cause to the local environment.

Organisers the Amaury Sport Organisation (ASO) have already had to reject claims that the 459 cars, bikes, trucks and quad bikes taking part in this year's edition will cause irreparable harm to ancient archaeological sites.

ASO, which also organises cycling's most prestigious and gruelling race, the Tour de France, is becoming used to dealing with such questions, as sport in general is increasingly scrutinised about its "green" credentials.

The Dakar rally first revealed its carbon footprint in 2007, trumpeting the fact that the 43,000 tonnes of greenhouse gases it produced was nearly a quarter of that at the French Open tennis tournament (156,000 tonnes).

Motorsport and in particular Formula One -- long demonised because of its reliance on the fossil fuels thought to contribute to global warming -- has led the way in publicising environmental attributes.

"We've got this image of waste but we don't pollute any more than other events," said Bernard Niclot, technical director at the International Automobile Federation (FIA) governing body.

"Motorsport has always contributed to the development of road cars. Even today, we still want it to help make cleaner, more fuel efficient cars and to respond to the challenges of diminishing oil supplies and protecting the environment."

FIA president Jean Todt, who formerly led the Ferrari F1 team, has been at the forefront of attempts to use renewable energy sources and staging quieter, more fuel efficient races.

Next year will see the launch of Formula E, with single-seater electric cars racing at speeds of up to 180 kilometres an hour on city circuits such as Rome.

Fuel limits will also be introduced in 2014 in endurance racing, following on from existing restrictions on wind tunnel tests, plus the number of engines and gearboxes available for drivers.

The Formula One Teams Association (FOTA) aims to reduce its overall carbon footprint by 15 percent in the coming years.

The use of artificial snow, tree felling and soil erosion in ski resorts or heavy water consumption on golf courses have long been targets for environmental campaigners.

But even apparently "green" sports cannot afford to rest on their laurels.

In 2009, there was outrage after images were shown of some 20 tonnes of rubbish left on Mont Ventoux after the advertising caravan on the Tour de France came through, distributing free gifts to the tens of thousands of fans parked by the road.

Some 50 tonnes of rubbish was produced during the 2011 New York Marathon while about 20,000 of the 47,000 participants came from abroad, most of them by high polluting air travel.

According to campaigners, serious thought has to be given to big sporting events, no matter how much organisers claim to be meeting environmental targets on use of sustainable materials or recycling.

"Tens of thousands of spectators pollute more at an autosports competitions than the racing cars," said Edouard Donnelly, a sustainable development expert at Paris-based sports consultancy firm Keneo.

"There's no difference between the Tour de France and a motorsport race."

In France, an estimated 50 percent of 260,000 sports venues are said to be poorly insulated, over-using water and electricity or not readily accessible by public transport.

Yachtswoman Isabelle Autissier, who is also head of the French branch of the World Wide Fund for Nature (WWF,) said environmental damage was the paradox of the modern day sports industry.

"We're building more and more big structures. We're getting people to come from farther afield," she said.

"By attracting more people we obviously generate more waste and damage because transporting sportsmen and women and spectators has more of an impact."

French Green Party lawmaker Jean-Luc Bennahmias said any steps taken were currently no more than a smokescreen, highlighting world football governing body FIFA's decision to award Qatar the 2022 World Cup.

The Gulf state is building 12 new air-conditioned stadia. Foreign fans will all travel by plane while the venues will become white elephants after the competition, he said.