It is estimated that air pollution causes several hundred thousand deaths a year around the world. Although there is some controversy over the magnitude, some highly regarded academic experts have estimated that even with the US Clean Air Act, among the most stringent air quality laws in the world, as many as fifty thousand Americans annually die prematurely as a result of air pollution. Perhaps the leading cause of air pollution related death in both industrialized and developing countries is particulate matter - soot and dirt particles that cause respiratory failure. Another major health concern is ground level ozone often experienced as urban smog. This can cause premature death and is the source of considerable discomfort and lost workdays in cities around the world. Lead emissions from gasoline have impaired intelligence of children and this realization has caused many countries to move toward a phase out of lead in fuels. Sulfur dioxide emissions may place asthmatics and others with respiratory disease at risk. Generally the elderly and children are the most vulnerable groups. Just over 50 years ago the US was shaken by an air pollution disaster in Donora, a small Western Pennsylvania town that claimed 50 lives in a few days. Air pollution today poses risks to millions worldwide, especially children in the world's largest cities. A symposium held in Washington, DC in February 2000 highlighted the gravity of the air pollution problem in China.
Ultraviolet radiation which will increase as a result of depletion of the stratospheric ozone layer has a number of adverse effects on human health including increased risks of various forms of skin cancer, weakening of the human immune system and increased risk of eye disorders such as cataract problems.
Policies and measures to reduce emissions of greenhouse gases are also likely to have other non-climate related effects on human health. Many strategies such as those encompassing enhanced energy efficiency and movement to non-carbon fuels may also have sizable air quality benefits, particularly reduced deaths from exposure to inhalable particles. An international group of health scientists estimated in 1997 that the adoption of moderate carbon emission control policies worldwide would reduce deaths from particulates alone by about eight million between 2000 and 2020. The IPCC and several other groups including the Climate Institute in March 2000 organized a workshop in Washington on ancillary benefits and costs of greenhouse mitigation policies. Research is needed to get an understanding of likely ancillary effects, i.e. benefits and costs in areas other than climate protection of greenhouse emission mitigation policies.
The international community is currently wrestling with the need to limit greenhouse emissions in order to prevent rapid global atmospheric warming. Policymakers perceive climate protection as a long-term challenge whose principal benefits may be reaped by generations yet to be born. However, most of the concrete actions that are available to limit greenhouse gas emissions may also have significant potential to enhance local air quality and contribute to health and other non-climate related benefits right away.
Climate and air quality protection efforts in most parts of the world tend to be undertaken independently of each other. This lack of coordination has a number of drawbacks from both an economic and an environmental standpoint. Industry finds that it may be faced with multiple bite regulation where it may need in one year to make carbon reductions and in another reductions in conventional air pollutants. The resulting uncertainty itself is a hindrance to long term planning. From an environmental perspective approaching climate and air quality protection in isolation has a number of pernicious effects: less overall environmental protection for the societal resources expended as uncoordinated strategies tend to focus too heavily on end of pipe controls and too little on energy efficiency and switching to less carbon intensive fuels and difficulty in building a public constituency for the changes needed for a transformation to sustainable energy systems.
By designing, implementing and publicizing an integrated strategy for climate and air quality protection immediate benefits in improved respiratory and cardiovascular health may be achieved for the most vulnerable parts of the population - the elderly, the young and asthmatics of all ages. These policies which will achieve significant carbon reductions and climate protection benefits inuring especially to future generations in all countries may be salable in developing countries as the benefits of enhanced air quality are realized by their inhabitants. Besides addressing the North / South disputes that have bedeviled the climate negotiations so long, a harmonized strategy also addresses intergenerational equity challenges by meeting needs of populations vulnerable to poor urban air quality and at the same time speeding a transition to less carbon intensive energy systems essential for safeguarding the climate of future generations worldwide.
The most detailed work on harmonized strategies for climate and air quality protection is contained in a STAPPA/ALAPCO study released in late 1999 describing how such strategies might be carried out in the US. Some of these strategies are being built into Mexico City's long range air quality protection plan as Mexican law is more flexible than US law to enable such a harmonized approach to be used