Environmental Issues Brainstorm WITHOUT TALKING, brainstorm individually and write down as many environmental issues as you can think of. 6) 7) 8) 9) 10) 1) 2) 3)4) 5)
Environmental Problems Pollution
POLLUTION What is it? • Harmful substances discharged into the air, soil, or water • EX: garbage, chemicals, radioactive waste, noise, thermal, light, sewage, pesticides, fertilizers Why do we care? • Pollution destroys environments, kills species, spreads disease, causes cancer; reproductive and respiratory problems in humans and animals • Air pollution is the main cause of global warming Solutions • Properly dispose of polluting substances • Monitor emission levels to be within acceptable limits • THREE R’s
Environmental Problems Ozone Depletion
OZONE DEPLETION • 78% nitrogen gas • 21% oxygen gas • 1% other gases Ozone Layer • Ozone layer absorbs 97% to 99% of ultraviolet (UV) radiation from the sun
OZONE DEPLETION What is ozone? Ozone a 3-atom molecule of oxygen (O3) This is a completely different compound than the oxygen we breathe (O2). Ozone is actually a toxic gas when given off at ground level.
OZONE DEPLETION Chlorofluorocarbons (CFCs) Chemicals once used in aerosol cans, plastics, and refrigerators that are now mostly banned. CFCs break up the ozone layer. The major problem: After a chlorine (Cl) atom removes an oxygen molecule from O3 it is able to separate from the lone oxygen atom and combine with another O3 molecule, so the process continues over and over and over again (up to 100 years).
OZONE DEPLETION Chemical Break-down of Ozone After breaking down an ozone molecule, the chlorine atom frees itself from the oxygen atom to restart the reaction.
OZONE DEPLETION Effects of Ozone Depletion Without the ozone layer larger amounts of UV rays can reach the earth and potentially cause cancer in humans, cause cataracts (damage eye-sight), and affect crop growth. • UV induces skin cancer by causing mutations in DNA. • The United Nations Environment Program estimates that a sustained 1 percent depletion of ozone will ultimately lead to a 2-3 percent increase in the incidence of non-melanoma skin cancer.
Other Effects of Ozone Depletion UV radiation also impairs the process of photosynthesis in plants. Marine organisms living in shallow water experience damaging levels of ultraviolet (UV) radiation. A healthy green sea urchin embryo appears above left. A UV-irradiated green sea urchin embryo (above right) displays an abnormal, extruded gut. Overexposure to ultraviolet radiation can change the flowering times of some kinds of plants and therefore will affect the animals that depend on them.
OZONE DEPLETION • The good news is that CFCs have been banned and can no longer damage the ozone layer • Montreal Protocol treaty including over 200 countries has banned the use of CFCs. Since the Montreal Protocol, is the ozone layer completely back to normal? The ozone layer is predicted to make a recovery to what it was in 1980 by 2050
OZONE DEPLETION • http://www.epa.gov/ozone/science/movies/forecastearth_3_300.wmv
Environmental Problems Deforestation / Habitat Loss
DEFORESTATION What is it? • Natural environments destroyed due to agriculture, excessive logging, forest fires, industrial and residential development Why do we care? • Loss of biodiversity • Greatest cause of extinction • Trees act as filters for excess CO2 in the air; less trees more CO2 • Not sustainable in the long term • New medicines, foods, and products Solutions • Conserve natural areas • Designate more lands for national/state parks • Sustainable agriculture
These NASA photographs, showing the destruction of the Amazon Rain Forest, provide a visual indication of the rate of deforestation that is taking place in Brazil. In many areas, the amount of clear-cut area now exceeds the area of remaining rain forest timber stands. The solid dark green areas show the remaining tropical rain forest canopy. Scientists predict that half of the Amazon Rain Forest will be gone by 2030. 1985 1992
GoogleMaps: Amazon See these light patches all over? Click the map above to see Amazon deforestation through GoogleMaps.
DEFORESTATION A Solution you can Take Part in!!
Environmental Problems Acid Rain
ACID RAIN What is it? • Precipitation becomes acidic due to air pollution • Burning fossil fuels (emissions from high sulfur coal) • Sulfur dissolves and mixes with oxygen to become acidic
ACID RAIN Why do we care? • Damage caused by Acid Rain: • Forests and soil • Aquatic ecosystems • Materials (building, statues, etc.) • Air Visibility (smog) • Human Health (heart and lung disorders)
ACID RAIN Solutions • Burn less high sulfur coal • Develop alternative energies
Environmental Problems Human Population Growth World population didn’t hit 1 Billion until around 1850.
HUMAN OVERPOPULATION ? Which parts of the world have the highest rate of population growth? How many people can the Earth support before it reaches its carrying capacity?
HUMAN OVERPOPULATION Population density per square kilometer
HUMAN OVERPOPULATION What is it? • Skyrocketing world population in the last 150 years • Due to industrial revolution, advances in medicine, food, and technology Why do we care? • Population cannot grow indefinitely (carrying capacity) • Larger population more pollution, scarcity of resources Solutions • Education • Fight poverty • ZPG = Zero Population Growth (Birth Rate = Death Rate) • Family Planning Activity with China, India & Kenya
HUMAN OVERPOPULATION Links to Check Out www.census.gov/main/www/popclock.html www.BreathingEarth.net www.pbs.org/wgbh/nova/worldbalance/