Did you ever see a sky without contrails?
In the three days after the terrorists attacks on September 11, 2001, jet airplanes did not fly over the United States. Without the gases from jet contrails blocking sunlight, air temperature increased 1°C (1.8°F) across the United States. This is just one of the effects air pollution has on the environment.
Smog Effects on the Environment
All air pollutants cause some damage to living creatures and the environment. Different types of pollutants cause different types of harm.
Particulates reduce visibility. In the western United States, people can now ordinarily see only about 100 to 150 kilometers (60 to 90 miles), which is one-half to two-thirds the natural (pre-pollution) range on a clear day. In the East, people can only see about 40 to 60 kilometers (25-35 miles), about one-fifth the distance they could see without any air pollution (Figure below).
Smog in New York City.
Particulates reduce the amount of sunshine that reaches the ground, which may reduce photosynthesis. Since particulates form the nucleus for raindrops, snowflakes, or other forms of precipitation, precipitation may increase when particulates are high. An increase in particles in the air seems to increase the number of raindrops, but often decreases their size.
By reducing sunshine, particulates can also alter air temperature as mentioned above. Imagine how much all of the sources of particulates combine to reduce temperatures. What affect might this have on global warming?
Ozone damages some plants. Since ozone effects accumulate, plants that live a long time show the most damage. Some species of trees appear to be the most susceptible. If a forest contains ozone-sensitive trees, they may die out and be replaced by species that are not as easily harmed. This can change an entire ecosystem, because animals and plants may not be able to survive without the habitats created by the native trees.
Some crop plants show ozone damage (Figure below). When exposed to ozone, spinach leaves become spotted. Soybeans and other crops have reduced productivity. In developing nations, where getting every last bit of food energy out of the agricultural system is critical, any loss is keenly felt.
The spots on this leaf are caused by ozone damage.
Oxide air pollutants also damage the environment. NO2 is a toxic, orange-brown colored gas that gives air a distinctive orange color and an unpleasant odor. Nitrogen and sulfur-oxides in the atmosphere create acids that fall as acid rain.
Lichen get a lot of their nutrients from the air so they may be good indicators of changes in the atmosphere such as increased nitrogen. In Yosemite National Park, this could change the ecosystem of the region and lead to fires and other problems.
Find out more at http://science.kqed.org/quest/audio/lichen-point-to-pollution/.
- An increase in particulates may reduce photosynthesis, increase precipitation, and reduce temperatures.
- Ozone may damage native plants and some crop plants by slowing growth or damaging leaves.
- Nitrogen and sulfur-oxides are pollutants. They also create acids in the atmosphere that fall as acid rain.
Use this resource to answer the questions that follow.
https://www.youtube.com/watch?v=rXlbcbh23_M Start with 3:58, end with 10:00
- What was the first smog caused by in Britain?
- What caused smog to increase greatly in Britain and when?
- What happened in London in 1952?
- What type of fog is found in Los Angeles and what causes it?
- What is smog in Beijing caused by?
- How much has the lifespan of residents been reduced? What other health effects are there?
- How many micrograms of fine particulates are recommended as a limit by the World Health Organization? How many were in the air in Beijing in January 2014?
- What was the result of this smog?
- What are the human health consequences?
- What does acid rain do to the environment?
- What do sulfur dioxide do to stone and metal?
- Does smog affect plant growth?
- What is the effect of an increase in particulates on the environment?
- What is the effect of ozone on native and crop plants?
- What happened to air temperature when jet airplanes could not fly over the United States for three days? Why? If smog were reduced what effect might that have on temperature?