Air Pollution and Climate Changes APES Study Guide

Pollution: The introduction of harmful substances or contaminants into the environment.

Electrostatic Precipitator: A device that removes fine particles from a gas stream using electrical charges.

VOC’s (Volatile Organic Compounds): Organic chemicals that evaporate easily at room temperature, contributing to air pollution and smog.

Heat of Fusion: The amount of energy required to change a substance from solid to liquid without a temperature change.

Point Source vs. Non-Point Source:

• Point Source: A single, identifiable source of pollution (e.g., a factory smokestack).

• Non-Point Source: Diffuse sources of pollution (e.g., runoff from agricultural fields).

Troposphere: The lowest layer of the atmosphere where weather occurs.

PM / Particulate Matter: Tiny solid or liquid particles suspended in air that can harm health.

Stratosphere: The atmospheric layer above the troposphere, containing the ozone layer.

CFC’s (Chlorofluorocarbons): Chemicals that destroy ozone in the stratosphere, leading to ozone depletion.

Paris Accord / Agreement (2015): An international climate agreement aiming to limit global temperature rise.

Greenhouse Effect: The trapping of heat in Earth’s atmosphere by greenhouse gases.

Kyoto Protocol (1992): An international treaty committing countries to reduce greenhouse gas emissions.

Albedo: The reflectivity of a surface; ice has a high albedo, reflecting sunlight.

IPCC (Intergovernmental Panel on Climate Change): A scientific body that assesses climate change research.

Mitigation: Actions to reduce or prevent greenhouse gas emissions.

Cap and Trade on Carbon Emissions: A market-based system where companies can buy and sell allowances for emissions.

Weather vs. Climate:

• Weather: Short-term atmospheric conditions.

• Climate: Long-term patterns of weather in an area

Concepts and questions:

In which layer of the atmosphere does weather occur?

• The troposphere.

What are the six EPA Criteria air pollutants?

• Carbon monoxide (CO) – from vehicle emissions

• Lead (Pb) – from past use in gasoline

• Nitrogen oxides (NOx) – from burning fossil fuels

• Particulate matter (PM) – from construction and wildfires

• Ozone (O3) – secondary pollutant from NOx and VOCs

• Sulfur dioxide (SO2) – from burning coal

Why is ozone a benefit in the stratosphere but a problem in the troposphere?

• In the stratosphere, ozone protects against UV radiation.

• In the troposphere, ozone is a pollutant that causes respiratory issues.

Which particulates are considered more dangerous to health, large or small? Why?

• Small particulates (PM2.5) are more dangerous because they penetrate deep into the lungs and bloodstream.

Which greenhouse gas has the greatest effect? Why is this a complicated question?

• Water vapor (H₂O) has the largest effect but is naturally regulated. CO₂ has a long-term impact because human activities increase its concentration.

Which legal act primarily protects air quality?

• The Clean Air Act (1970, amended 1990).

Which pollutants are reduced by the catalytic converters in cars?

• Carbon monoxide (CO), nitrogen oxides (NOx), and hydrocarbons (VOCs).

How was lead pollution significantly reduced in the 1970s?

• The phase-out of leaded gasoline.

What is the Paris Accord? What happens if a country fails to meet its goal?

• An agreement to limit global temperature rise. There are no strict penalties, but there is international pressure.

How does the melting of sea ice and glacial ice increase the warming of the planet?

• Lower albedo means less heat is reflected, causing more warming.

Why would a cap and trade system of reducing carbon emissions be an easier way to get companies to reduce greenhouse gas emissions than simple penalties?

• It creates an economic incentive by allowing companies to buy and sell emissions credits.

What is the relationship between carbon dioxide concentration in the atmosphere, ocean carbon dioxide concentration, and ocean pH? Why is ocean pH important? Which organisms are most affected by a drop in ocean pH?

• More CO₂ in the atmosphere leads to more CO₂ dissolving in oceans, forming carbonic acid, which lowers pH (ocean acidification).

• Coral reefs, shellfish, and plankton are most affected.

What have carbon dioxide levels looked like over the past 800,000 years?

• CO₂ levels have fluctuated naturally but are now higher than at any point in history (423 ppm in 2024).

14. How do carbon dioxide concentrations and temperature compare?  Do they follow the same patterns, or not?  Refer to the graph below.

• They follow the same pattern—when CO₂ increases, temperature increases.a