Section 16 2 Air Quality Biology Objectives Describe

Section 16. 2: Air Quality Biology

Objectives Describe the sources, types and effects of air pollution. How do pollutants accumulate in the air? How is air pollution contributing to acid rain? How is air pollution changing Earth’s biosphere?

Pollution Pollution: any undesirable factor, or pollutant, that is added to the air, water, or soil Microscopic air particles Waste products from factories and sewers Household chemicals poured down the kitchen sink Types of Pollution: Smog and Ozone Acid Rain

Smog & Ozone The most common form of pollution comes from the waste products produced by burning fossil fuels The products combine together in the air to produce a haze called smog Smog: Type of air pollution caused by the interaction of sunlight with pollutants produced by fossil fuel emissions Components of Smog: Particulate Matter Ground-Level Ozone

Smog: Particulates are the microscopic bits of dust, metal, and unburned fuel that are produced by many industrial processes 1 -10 microns in size Can stay in the air for weeks before they settle to the ground These particulates can be inhaled and can cause many different types of health problems

Smog: Ground-Level Ozone In the presence of sunlight, two types of chemicals react to produce ground-level ozone (O 3) NO 2 + O 2 O 3 + NO- The ozone stays close to the ground where it is hazardous to human health (O 3 can cause cells to die) Ozone is only harmful when close to the ground, it plays a big part in the outer stratosphere to keep the Earth’s atmosphere protected from ultraviolet Sun rays

Acid Rain The burning of fossil fuels also causes the production of nitrogen oxides and sulfur oxides Acid Rain: type of precipitation produced when pollutants in the water cycle cause rain p. H to drop below normal levels Acid rain has a major effect on ecosystems, as the decrease in p. H threatens water supplies and species habitats. It also causes a decline in growth rate for plants, as well as making trees (our carbon sinks) more vulnerable to disease and weather

Formation of Acid Rain During normal rain fall carbon dioxide in the air reacts with the falling water to form a weak carbonic acid, leaving Hydrogen ions Normal rain has a p. H of 5. 6 When pollutants become a part of the water cycle, creates sulfuric and nitric acids, which cause the p. H to fall below 5. 6 Roughly a p. H of 4. 6, which is a whole p. H level!

Carbon Dioxide And The Biosphere The atmosphere naturally includes carbon dioxide Important to keep the temperature that can support life Levels of carbon dioxide rise and fall over time There is a direct link between the global average temperature and the carbon dioxide levels High levels of carbon dioxide are linked to Earth’s warmer periods Low levels of carbon dioxide are linked to period of extreme cold, like the ice age

The Greenhouse Effect Normally, the Sun emits visible and invisible light Some of these rays are absorbed the Earth’s atmosphere, while others pass through the atmosphere to the Earth’s surface The ground absorbs some of energy and reradiates it as heat, bouncing it up and down from ground to atmosphere, keeping the Earth’s temperature high enough to sustain life

The Greenhouse Effect The atmosphere contains gases that play an important role in acting as insulators, slowing the loss of heat into space Water vapor, carbon dioxide, and methane are the most common Greenhouse Effect: when carbon dioxide, water, and methane molecules absorb energy reradiated by Earth’s surface and slow the release of this energy from Earth’s atmosphere

Global Warming The trend of increasing global temperatures Changes in temperature are due to the increase of greenhouse gases in the atmosphere These gases are also produced by industrial processes and the burning of fossil fuels Human impact IS influencing global warming Must take steps to slow the warming process

Global Warming Atmospheric changes will affect the global biosphere Increase in ecological disasters: flooding, strong tropical storms, and other weather related issues Also, see an decrease in biodiversity Also, the increase in temperature is melting the polar ice caps Increased temperatures from 1. 4 to 5. 8 degrees Celsius by the year 2100

Output Explain in a drawing or paragraph how the build-up of carbon dioxide in the atmosphere could increase Earth’s global temperature.