Vehicle manufacturers can now also 'reflect on what has been achieved so far and the challenges that lie ahead', said the European Automobile Manufacturers Association (ACEA).
It lists some of those achievements as 'the significant' reduction in exhaust emissions and noise levels, the 'numerous initiatives' on vehicle recycling, vehicle safety improvements, reduced energy and water consumption and improved manufacturing processes.
ACEA says that the combined emissions of 100 new cars made today produce no more pollution than the emissions of just one average car built in the 1970s.
'Still the challenge lying ahead is demanding,' the ACEA admits, adding that the focus is now on improving traditional fuel technologies, developing energy and powertrain alternatives, enhancing the safety of road users and designing solutions that integrate public and private means of transport.
'Our industry is strongly committed to that,' said Ivan Hodac, ACEA secretary-general. 'Mobility cannot be limited and should not be limited. The free movement of people, goods and ideas is a basic human desire and an essential facilitator of economic and social development, and of quality of life.'
Hodac added: 'In today's global world, mobility needs are increasing, both in developing countries and in the industrialised ones.
'What we are doing is making mobility affordable to most people and making it more sustainable and efficient, not only in terms of environment, safety and occupation of space, but also from an economic and social point of view.'
European car makers have made serious and significant commitments to reduce the average greenhouse gas emissions of new cars over the next few years.
Via ACEA, manufacturers have agreed to reduce the average carbon dioxide emissions of all new cars to 140g/km by 2008, a reduction of 25% from 1995 levels, and to achieve an average fuel consumption of six litres/100kms (about 50mpg).
BMW is keen to kick-start the age of hydrogen, launching its CleanEnergy World Tour last year to promote the build- up of a hydrogen infrastructure.
It is the fuel many scientists believe will be the trump card in the battle to stabilise the world's climate and the manufacturer expects to have its first 7-series models powered by the fuel available to buy in the next four to five years. BMW is putting massive resources into developing hydrogen power because it believes the fuel can be produced by wind or solar energy with no knock-on pollution and will prove vehicle friendly.
Hydrogen is the most common and lightest element in the world. It is a component of water and all organic compounds and is colourless and odourless. When burnt, steam is the only tailpipe emission.
Commenting on BMW's involvement in the Earth Summit, member of the board of management Dr Norbert Reithofer, said: 'The BMW Group is taking part in Johannesburg because we firmly believe sustainability is more than just a vision of a distant future. Sustainability is the core of our corporate strategy and the key to our continued success as a manufacturer of premium automobiles.'
Volkswagen is also represented at the summit. A spokesman said: 'It is an opportunity for us not only to present details of our commitment to sustainability but also to pursue dialogue with representatives from politics, society and various societies and associations, and to produce clear, easily understood evidence of its policy of sustainable economic activity.'
VW also hosted a technology exhibition that demonstrated 'the work being carried out on power train and fuel technologies that make efficient use of energy and reduce pollutant emissions'.
Mercedes-Benz also had a strong presence at the summit – it provided a thousand white limousines to heads of state from around the world. Toyota, which has manufacturing plants in Europe, used the summit to host an exhibition that featured two hybrid vehicles – including its hydrogen-powered FCHV-4 prototype.
The manufacturer said it had 'long believed that hybrid technologies hold the key to the future of the automobile'.
It hoped its display would 'give visitors a clearer understanding of what it is doing to create a cleaner world through minimising emissions, while securing and even enhancing the freedom of mobility'.