Weathering release occurs of Ca and other ions into surface waters. Rainfall is acidic because atmospheric carbon dioxide dissolves in the rainwater producing weak carbonic acid. In unpolluted environments, the rainfall pH is around 5.6. Acid rain occurs when gases such as sulfur dioxide and nitrogen oxides are present in the atmosphere. These oxides react in the rain water to produce stronger acids and can lower the pH to 4.5 or even 3.0. Sulfur dioxide, SO, comes from volcanic eruptions or from fossil fuels, can become sulfuric acid within rainwater, which can cause solution weathering to the rocks on which it
Environmental standard that can be released into atmosphere in order to maintain air quality and human health and regulate the release of greenhouse gases such as carbon dioxide (CO), oxides of nitrogen and oxides of sulfur. The standards are established in two phases to stay up to date, with final projections aiming to collectively save Americans $1.7 trillion in fuel costs and reduce the amount of greenhouse gas emissions (GHG) by 6 billion metric tons. Similar to the ambient standards, individuals states may also tighten regulations. For example, California set their own emissions standards through the California Air Resources Board (CARB), and