Learn the chemistry behind acid precipitation
A substance is considered acidic when it has a relatively high concentration of H3O+ ions. Acidity is measured on a pH scale (with most values falling in the range from 0-14). Pure water is considered neutral, and is assigned a pH of 7. Substances with pH less than 7 are considered acidic. The lower the pH of a substance, the more acidic it is. Due to dissolved CO2, natural precipitation has a pH of about 5.6 (and is therefore naturally acidic). However, "acid precipitation" results from the presence of other acids such as sulfuric acid (H2SO4) or nitric acid (HNO3) or acid-forming substances such as sulfate ions (SO42-) or nitrate ions (NO3-), causing the pH to be lower than this. Remember that the pH scale is logarithmic, so a drop in pH by 1 unit represents a 10-fold increase in [H3O+]. So an acidified lake or river with a pH of 4.3 has a much greater concentration of H3O+ than that of natural rain precipitation, and can cause significant damage to organisms that depend on that water to sustain life.
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Different organisms have difference tolerances for increases in acidity, but minor effects in one species may contribute to effects elsewhere in an ecosystem. For example, the mayfly (an aquatic insect) will die from a small increase in the acidity of water, whereas frogs can tolerate a much higher increase in acidity. However, since the mayfly is a vital source of food to frogs, frog populations can decrease after small increases in acidity as well. This is only one example of how changes in acidity can disrupt the delicate balance that exists in ecosystems.

Vegetation can also be sensitive to increases in acidity. Increases in soil acidity can deplete the nutrients in the soil that plants need to grow. As well, increases in soil acidity can set off a number of chemical reactions that end up causing aluminum and other harmful metals to be released. 

Climate change – carbon dioxide

Carbon dioxide is a greenhouse gas. "Greenhouse gases" are atmospheric gases, which, despite their very low concentrations, cause the surface temperature of Earth to increase.  This is one of the substantial contributors to global climate change.

Naturally occurring greenhouse gases such as carbon dioxide make conditions on Earth suitable for life. However, the rapid increase in greenhouse gas emissions attributed to human activity has already had damaging effects on Earth’s climate, which are anticipated to become more severe as emissions increase. In terms of human health, likely impacts of atmospheric warming include freshwater shortages and compromised food supply. The number of days each year in warm climates, where temperatures exceed safe levels for humans is increasing.  It is anticipated that warmer temperatures will enable disease-carrying insects to expand their habitats. As a result, illnesses such as malaria, yellow fever, and sleeping sickness may become present in areas that haven’t been severely affected before.

Learn the chemistry behind greenhouse gases and our changing climate
The sun is the primary source of energy for Earth’s climate. An energy balance results from the amount of incoming solar energy, and the energy sent back into space by reflection from atmospheric and surface features, and radiation of energy from Earth in the infrared region of the spectrum. Greenhouse gases are substances in the atmosphere that absorb infrared radiation at the wavelengths at which Earth emits infrared radiation back into space. While greenhouse gases are produced both by natural processes and human activity, the large increase in the atmospheric concentrations of greenhouse gases such as carbon dioxide, methane, chlorofluorocarbons, and nitrous oxide since the industrial revolution is changing Earth’s energy balance. Our planet is warming as a result. To learn more about the chemistry behind our changing climate visit www.explainingclimatechange.com.
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Damage to plants  – ground-level ozone

Plants are very sensitive to ozone exposure. Ozone can damage various cells and cellular components of plants which can disrupt their ability to photosynthesize. When photosynthesis is compromised, plants are not able to grow as readily. For this reason, crop yields can be reduced due to increases in ozone.
The damaging effects of ozone on plants can be increased when other pollutants like sulfur dioxide are present.