An air quality standard when compared to existing air pollution levels can by itself inform the public about the extent of air pollution. However, by itself, it makes a poor goal. For a goal to have a meaningful impact, there needs to be a timeline defined for meeting the air quality standard as well as consequence for failing to meet the standard by the timeline. When standards are set without attendant timelines, little progress is typically made toward air quality because the air pollution technologist is always confronted with the debate about how fast to move. The solutions to virtually all air quality problems require significant changes in society varying from the addition of control equipment by the business community to the need to make lifestyle changes. These changes can cost considerable amounts of money and can result in social dislocation. Thus, the parties that must pay the cost or suffer the social dislocations almost always vigorously oppose them. These actions tend to slow or stop the air quality improvement process that does not include a clear attainment timeline established by the policy makers. The selection of a timeline is an important and difficult challenge that must balance health risks with economic and social considerations. An example of the lack of effectiveness of a goal without a timeline is the California Air Quality Standards, which have been set for some time but do not include a deadline nor consequences for attaining the standard. Hence, little progress has been made above and beyond the national standards to meet the California specific standards.

The timeline should include milestone goal amounts for both the interim and final goal. This allows for short and long term planning as well as the determination if reasonable progress is being met early in the process. The interim goal is usually set on an annual basis. Experience in California in the United States has indicated that it is possible to reduce emissions at the rate of 5%-8% per year without significant economic dislocation. While this experience may not be directly extrapolated to another country, it is at least a benchmark that might be considered. A 5% annual pollution reduction means that air pollution emissions will be cut in half in about 13 years while an 8% annual reduction means that air pollution emissions will be cut in half in about 8 years. Los Angeles, California, USA has reduced emissions by about 50% every 10 years for an average annual reduction rate of 7% since 1977. Countries embarking on an air pollution reduction program with little control applied to date might be expected to take advantage of controls applied in other parts of the world and reach an annual reduction rate of 10%.

The long-term or final goal deadline is also necessary if the standard cannot be met within a couple years. The final goal deadline is often set that is 5-10 years away. The long-term goal is useful to be able to provide a stable environment for pursuing long term endeavors, where large-scale processes and capital intensive changes only make sense over a long time period. Setting an overall long-term strategy will send the signal that major changes that are necessary can be pursued and the commitment for change, in spite of economic or political changes, is not going away.