Global warming, population growth, acid rain, eutrophication, CFCs/environmental toxins HUMAN IMPACTS

Global warming, population growth, acid rain, eutrophication, CFCs/environmental toxins HUMAN IMPACTS

GLOBAL WARMING

GLOBAL WARMING Trapping of warm air close to the Earth s surface due to emission of greenhouse gases such as H 2 O vapor, CO 2, and methane

WHAT CAN CAUSE GLOBAL WARMING? Increased burning of fossil fuels can cause greenhouse effect to be pronounced Fossil fuels non-renewable resources formed over millions of years under the Earth s surface from dead organisms rich in carbon and energy

WHAT CAN CAUSE GLOBAL WARMING? Results in the increase in global temperatures, melting of polar ice caps, and increased sea levels. Loss of habitat for polar species such as the polar bear

WHAT CAN CAUSE GLOBAL WARMING? Islands become submerged due to increase in water levels Human activities (increased burning of fossil fuels, cars, industrial revolution) all have led to increased carbon dioxide emission

WHAT CAN CAUSE GLOBAL WARMING? More people leads to more energy needed which leads to more CO2 emissions which leads to increased global warming.

WHAT CAN CAUSE GLOBAL WARMING? CFCs (chloroflorocarbons) cause ozone depletion

POPULATION GROWTH

POPULATION GROWTH Population has grown exponentially since the Industrial Revolution.

WHY HAS THE POPULATION INCREASED? Lower infant mortality Lower death rate Longer life span due to better health care and technology. Over 7 billion people

WHY HAS THE POPULATION INCREASED? Have not yet reached carrying capacity; unknown as to when we will reach the cc Loss of habitats Increased use of natural resources.

WHY HAS THE POPULATION INCREASED? Human population pyramids : Age structure diagram showing the distribution of various age groups in human populations in a certain area. Faster growth = larger proportion of the population is in the younger age groups. **Look at the pyramids on the next slide.

HUMAN IMPACTS Acid Rain: caused by pollution in the atmosphere (nitrogen & sulfer oxides) which is given off into the atmosphere and creates precipitation that is acidic (ph <6)

HUMAN IMPACTS Acid Rain Affects organisms that depend on water (especially amphibians) Habitat degradation (limestone erosion, aquatic ecosystems) destruction of habitat Examples: Adirondack Park located in upstate NY (ph is now 200 times more acidic than natural rain with a ph of 3.3 or less) remember what is the ph of your stomach? 2 = very acidic

HUMAN IMPACTS Eutrophication caused by too many nutrients in a small body of water Creates algal blooms that can lead to fish kills due to lack of dissolved oxygen Result of run-off of fertilizer from farmland, waste lagoons on hog farms, golf courses (high in nutrients)

HUMAN IMPACTS Environmental Toxins: can bioaccumulate (toxins accumulate in cells as organism moves up the food chain)

HUMAN IMPACTS Lead heavy metal found in batteries, old paint and pipes in buildings, industrial use in factories and garages. Can lead to tissue damage (heart, lung, nervous system, bones, etc.) Can cause learning and behavior problems in children

HUMAN IMPACTS Mercury major source is in fish from bioaccumulation from pollution washing mercury into water. Can cause damage to brain, kidneys and lungs. Can also cause neurological problems in children.

HUMAN IMPACTS DDT chemical used to kill mosquitoes (not used anymore). Bioaccumulation predatory birds eating insects sprayed with DDT. Resulted in thin egg shells. Example: Peregrine falcon (endangered species).

HUMAN IMPACTS Invasive Species exotic, non-native species live in areas where native species live. Compete with native species for resources. Usually will grow fast, decrease biodiversity.

HUMAN IMPACTS Note native species die out because of invasive species Example: Kudzu (Japenese vine), zebra mussel, snakehead fish, brown snake in Guam

HUMAN IMPACTS Habitat destruction destroy places where organisms live Loss of habitat due to human population growth in areas (inhabitation new houses built), mining, agriculture, etc. Deforestation/Clear cutting - Can result in a loss of biodiversity extinction of species, soil erosion.