Learning Objectives 1 Explain the advantages and disadvantages
Learning Objectives: 1. Explain the advantages and disadvantages of non-renewable energy sources as well as how the increasing human population and industrialization have lead to a greater consumption of them by reading a science text and completing a tree map. 2. SWBAT: Explain how air pollutants contribute to environmental problems such as smog, acid rain, global warming and ozone depletion by reading a science text and completing a chart on the causes and effects of these problems.
-Energy is the power we use for transportation, for heat and light in our homes and for the manufacture of all kinds of products. As the human population increases, there is a greater demand for Earth’s resources. -At present, the human population is roughly 8 billion…and it is increasing! Humans have a carrying capacity and the resources we use are finite. -As our population continues to increase, we are using more and more resources, particularly non-renewable ones (fossil fuels and nuclear energy) -As a result of Industrialization or the large scale introduction of machines and factories that produce goods, vast quantities of fossil fuels have been used. (factories, automobiles and powerplants burn fossil fuels to create energy). The Human Population
Types of Energy Sources • Renewable/Alternative resources can regenerate and are replaceable (but not unlimited) – Fresh water, wind, solar, biomass, and geothermal-does not pollute air!! • Nonrenewable resources cannot be replenished by natural processes (finite or limited) – Fossil fuels (oil, natural gas, coal)-pollutes the air when burned which causes smog, acid rain and contributes to global warming. – Nuclear power (uranium)-produces radioactive wastes and contributes to thermal pollution. • Sustainable use is a way to use resources at a rate that does not deplete them or cause long-term harm to ecosystems by creating a loss of biodiversity.
Air Pollution
Causes of Air Pollution • One of the main causes of air pollution is the release of carbon dioxide into the atmosphere from activities that burn fossil fuels (deforestation contributes to this issue). • Other pollutants are released from burning fossil fuels which leads to acid rain (nitrogen oxide and sulfur dioxide gases) and (ground level ozone gas) smog. • CFC’s released from our homes and specific products lead to the depletion of the ozone layer.
Ozone Depletion • Chlorofluorocarbons (CFCs) reduce the amount of ozone gas (a layer of protective gas in the stratosphere. CFCs come from a variety of places such as aerosols sprays, refrigerators and AC’s, as well as foam and packaging materials. • CFC’s deplete ozone gas which then allows more UV rays to reach earth. As a result, there is a greater incidence of skin cancer and cataracts for humans. • Phytoplankton (producer in marine food web) are dying from exposure to UV rays.
Ozone Depletion
Global Warming • Burning fossil fuels release greenhouse gases such as carbon dioxide into the atmosphere. • Increasing the amount of CO 2 in the atmosphere reinforces the greenhouse effect and is expected to result in an increased warming of the Earth's surface. This is known as Global Warming. • As a result, polar ice caps are melting, sea levels are rising, many organisms are changing their migration patterns, polar bears are losing their homes, increase in tropical storms.
The Greenhouse Effect
Acid Rain • When emissions of sulfur dioxide and nitric oxide from burning fossil fuels are transported long distances by winds, they mix with water vapor and produce acidic rain. • These chemicals descend to the earth's surface in wet form as rain or snow and in dry form as a gases fog, dew, or solid particles, it is known as acid rain or acid deposition. • As a result, fish and plants are being harmed by the increasing acidity of rain water.
Acid Rain
Acid Rain
Smog • When the pollutants react with the summertime sunlight, they form ground-level ozone, the main component in smog, a yellowish (“smoky fog”). • With the introduction of petroleum to replace coal economies in countries, photochemical smog has become predominant in many cities like NYC and Beijing , China, which are located in sunny, warm, and dry climates with many motor vehicles. • Worst episodes of photochemical smog tends to occur in summer.
NYC Smog
Natural Air Pollutants • Natural air pollutants can include: – Smoke from wild fires – Methane released from live stock – Volcanic eruptions
Summary & Reflection How can we reduce these problems? Reflection- Explain the causes and effects of air pollution.
How can we reduce these problems? Global Warming, Acid Rain & Smog-plant more trees (reduces CO 2) -reduce, reuse, recycle (uses less energy) -use alternative energy sources -carpool, mass transportation (uses less gas) Ozone Depletion- -products containing CFC’s are banned in the US
- Slides: 17