Authoritative scientific assessments have concluded that the world is already committed to experiencing these two environmental changes over at least the next few decades, even if radical reductions in emissions were achieved immediately. It is therefore important to assess how best to minimize adverse health impacts.
Since local emissions of greenhouse gases and ozone-destroying gases contribute to processes of global atmospheric change, preventive policies must be part of a coordinated international effort; it is not possible to mitigate their effects soley on a local or regional basis. Thus countries have a moral obligation to contribute to preventive efforts on behalf of human wellbeing and health everywhere. The corollary to this is that taking local adaptive action, in the absence of such mitigation attempts, entails an unethical decision to protect local populations when more distant populations may be less able to protect themselves.
Road transport is a key target area to achieve benefits both in reducing greenhouse gas emission, and in curbing other transport-related health impacts, such as those resulting from other air pollutants, noise, accidents and reduced opportunities for physical exercise through walking and cycling. Transport is at the moment the fastest growing source of CO2 emissions. About 26% of all carbon dioxide emissions in the Europe Union are caused by the transport sector, and they show an upward trend. Emissions from transport in the EU increased by 30% between 1985 and 1996, and the projected increase in passenger car transport in the EU is a further 30% increase by 2010 despite the targets in the Kyoto Protocol.