Four international agencies have urged the world's motor industry to halve CO2 emissions from cars by 2050.
The call comes as Achim Steiner, United Nations Under-Secretary General, predicts the number of cars in the World is due to triple by 2050, reports the BBC website.
Therefore the motor sector is being encouraged to reduce emissions to help the environment.
Industry executives at this week's Geneva motor show have reportedly responded positively to the news.
They believe generally speaking the cuts are possible.
However, chief executive of Daimler Dieter Zetsche, which owns Merecedes, Smart and Maybach, said the aim should be treated with caution.
Zetsche said there is always the question of how fast you can develop and ultimately the goal must be emission free driving.
Toyota Motor Europe executive Graham Smith, agreed the target sounded achievable.
Overall Toyota's fleet average carbon dioxide emissions are currently 140 grams per kilometre, well below the industry average and set to drop to 95 grams by 2020.
However Aston Martin chief Ulrich Bez took a different view on emissions produced by power generators delivering electricity to households and factories, as well as by cars and airlines.
Bez told the BBC England wastes £800m a year by not insulating houses, which represents more CO2 emissions than running 20,000 Aston Martins for 100 years.
The four international agencies are the UN Environment Programme (UNEP), the International Energy Agency (IEA), the International Transport Forum (ITF) and the FIA Foundation.