<P> In 2007, total SO emissions were 8.9 million tons, achieving the program's long - term goal ahead of the 2010 statutory deadline . </P> <P> In 2007 the EPA estimated that by 2010, the overall costs of complying with the program for businesses and consumers would be $1 billion to $2 billion a year, only one fourth of what was originally predicted . Forbes says: In 2010, by which time the cap and trade system had been augmented by the George W. Bush administration's Clean Air Interstate Rule, SO2 emissions had fallen to 5.1 million tons . </P> <P> The term Citizen science can be traced back as far as January 1989 and a campaign by the Audubon Society to measure Acid rain . Scientist Muki Haklay cites in a policy report for the Wilson Center entitled' Citizen Science and Policy: A European Perspective' a first use of the term' citizen science' by R. Kerson in the magazine MIT Technology Review from January 1989 . Quoting from the Wilson Center report: "The new form of engagement in science received the name "citizen science". The first recorded example of the use of the term is from 1989, describing how 225 volunteers across the US collected rain samples to assist the Audubon Society in an acid - rain awareness raising campaign . The volunteers collected samples, checked for acidity, and reported back to the organization . The information was then used to demonstrate the full extent of the phenomenon ." </P> <P> The most important gas which leads to acidification is sulphur dioxide . Emissions of nitrogen oxides which are oxidized to form nitric acid are of increasing importance due to stricter controls on emissions of sulphur containing compounds . 70 Tg (S) per year in the form of SO comes from fossil fuel combustion and industry, 2.8 Tg (S) from wildfires and 7--8 Tg (S) per year from volcanoes . </P>

What are some harmful side effects produced by acid deposition