Reduction of CO2 Emissions

• Soot particles (diesel vehicles) – tiny particles of carbon are produced which can carry fuel

and oil. The start of injection influences the emission of soot particles; if the start of injection

is delayed such that there is incomplete combustion, increased levels of soot particles will

result. The use of high injection pressures, particularly at low engine speeds can greatly

reduce soot emissions and optimum injection direction such as that provided by EUI nozzles

(used on Discovery II) help to limit black smoke production. Growing concern has been attracted by the emissions of particulate matter, since it is

composed of tiny particles which can linger in the lungs with serious health effects, including

cancer.

In addition to the above, the transport sector produces a substantial share (about 30%) of emissions of non-methane volatile organic compounds (VOC) in Europe. Other air pollutants of concern come from substances in petrol such as lead and benzine which are also considered to be carcinogenic.

The European Commission proposes to limit benzene values from 1st January 2010 and carbon monoxide levels from 1st January 2005. The two pollutants have been exempt from controls so far, but have been linked to an increased risk of leukaemia and heart disease.

Motor vehicle emissions also create concentrations of ozone at ground level which when exposed to heat form the type of pollution known as “summer smog”. Ozone causes breathing problems, reduced lung function, asthma, eye irritation, nasal congestion and reduced resistance to colds and other infections. Ozone can be especially dangerous for the young and the elderly, and can also damage plants and trees and cause deterioration of rubber and fabrics.

The approximate proportions of exhaust gas constituents for modern petrol vehicles is listed below:

• Water (H₂O) – 14%
• Carbon Dioxide (CO₂) – 13%
• Nitrogen (N) – 72.9%
• CO + NO_x + HC = 0.1%

Reduction of CO2 Emissions

One of the conclusions reached by the European Union Council for the Environment on the 25th June 1996 was an agreement for a Community strategy to reduce CO₂ emissions from passenger cars and the improvement of fuel economy to reduce the average CO₂ emissions of newly registered passenger cars to 120 g of CO₂ per kilometre by 2005 or 2010 at the latest.

A voluntary agreement between the European Commission and the European Automobile Manufacturer's Association (ACEA) under the 'Auto-Oil Programme' in 1999, included the commitment to achieve an emission target of 140 g of CO₂ per kilometre for the average of the new car sales by ACEA members in the EU by 2008 and 120 g/km by 2012. Japanese and Korean associations of automotive manufacturers (JAMA and KAMA) are negotiating with the Commission to conclude environmental agreements equivalent to that agreed to by ACEA.

Although these voluntary measures require additional investments in technology by the manufacturers (e.g. improved combustion engines, new means of propulsion etc.), these costs are justified on the grounds of protection of human health and the environment.