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Explore the impact of human behavior on environmental health, the balance of Earth's ecosystem, population growth issues, disparities between high and low-income countries, resource consumption and overpopulation concerns.
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Rats brought the plague. • Rats increased. • Cats died. • Caterpillar numbers went up. • WHO sent DDT to Borneo. • Mosquitoes were wiped out. • Caterpillars ate grass roofs. • Cats were parachuted in. • Cats caught lizards containing DDT. • Roaches stored DDT in their bodies. • Lizards disappeared. • Lizards slowed down. • Lizards ate roaches and got DDT. • Bad Mosquitoes
Bad Mosquitoes • WHO sent DDT • Mosquitoes Died • Cockroaches stored DDT • Lizards at cockroaches • Lizards slowed down • Cats ate lizards • Lizards Disappear • Cats die • Caterpillar #’s increase • Caterpillars ate grass roofs • Rats increase • Rats spread plague • Cats are Parachuted into Borneo
Purpose of Environmental Science – assess the state of the abiotic and biotic interactions and how they affect the overall environmental health of a region, state, nation and the planet giving special consideration to the impact of human behavior
Maintaining Balance Earth – well suited for life • positionfrom the sun– not too hot, not too cold • plenty of water • enough sunlight to drive photosynthesis • atmospheric gases support life • minerals and nutrientsfor growth and development
Changes disrupt life’s balance • human activity - largest agent of environmental change Ex: Use and depletion of natural resources • Pollution • Extinction of other species • Introduction of foreign species– Zebra muscle, kudzu, gypsy moth, Japanese Beetle • Alteration of Ecosystems
Humanity Major Impact – Population Basic Example: 10 gallon aquarium = 10 inches of fish - why? Availability of nutrients and the accumulation of waste - more fish = necessity for more nutrients and the production of more waste
Human Population: • Population Growth – page 4 • Estimated Size > Population Clock • rapid growth means impact on human quality of life and environmental health
Result of a large population = fewer resources per person Poverty • Poverty: WHO (World Health Organization) definition = making less than one dollar a day • Associations of Poverty: low life expectancy, illiteracy, inadequate access to health services, safe water and balanced nutrition • Solutions: Population control • May not be culturally or religiously accepted
Rich Countries Vs. Poor Countries Highly Developed Countries(HDC): 20% of world’s population Ex: US, Canada, Japan, most of Europe Moderately Developed and Less Developed (Poor) Countries(LDC): 80% of world’s population Ex: Bangladesh, Mali, Ethiopia LDC have many people for laborbutlittle economic resources for development - mostly agricultural – lots of poverty and disease - during development, rapid growth of population often causes a depletion in the natural resources
HDC and LDC disparity HDC use more natural resources per capita than LDC HDC (20% of world population) use over 50% of the resources • Draw two pie charts • 1 - Showing relative population sizes of HDC and LDC countries • 2 – Showing relative resource consumption of HDC and LDS countries
Unequal Distribution of Resources • The world is not homogenous. • Resources are clustered in different areas of the world. RESOURCES = $$$$$$
Types of Resources Non-renewable – in limited supply and are depleted with use and cannot be replenished by natural processes within a reasonable human time scale Ex: metallic minerals, non-metallic minerals, fossil fuels Renewable – can be replaced by natural processes Ex: fresh water, fertile soil, solar energy, wind energy, clean air, animal populations (barring extinction)
Renewable vs. Sustainable - overuse of a renewable resource may cause its depletion - need to be used in a sustainable way – gives time for replenishment
Resource Consumption - use of materials and energy • HDC individuals use a far greater amount of resources than LDC individuals Ex: amount of electricity and water used and waste generated, products consumed and the energy needed to produce it - Overconsumption due to overpopulation Overpopulation: when the level of demand on the resource base results in damage to the environment
Types of Overpopulation 1. People Overpopulation: too many people for the resources available – even if each person uses a small amount of the resources 2. Consumption Overpopulation: too many resources are used by each person (more than necessary) – consumption oriented lifestyle
Ecological Footprint - the average amount of productive land, fresh water and ocean required to supply a person with food, wood, energy, water, housing transportation and waste disposal on a continuous basis
- Earth contains 11.4 billion hectares (or 28.2 billion acres or 1.2 x 1014 ft2) of productive land and water • 1 hectare = 1.87 football fields - divided by the population results in a 1.9 hectares (4.7 acres) per person which is less than the current 2.3 hectare (5.7 acre) ecological footprint - RESULT: ECOLOGICAL DEFICIT which causes forest destruction, degredation of crop land, loss of biological diversity, declines in ocean fishing, and water shortages
HDC disparity: developing countries such as India have ecological footprints approximating 1 hectare (1.87 football fields) per person. US footprint is about 9.6 hectares. - If all the people in the world lived as US citizens lived, we would need 4 more planets for the necessary supplies - Ecological footprint is not only affected by the population but also by the level of development. As a nation getsmore and more developed it consumes more and more resources per person.
Impact Determination (IPAT MODEL) - the level of impact any activity causes can be estimated by the factors that cause it - the number of people involved (P) • the consumption or amount of resources used per person in that activity (A) • – known as the affluences • the environmental effects (T) of the technologies used to obtain and consume the resources • – this is a measure of the resources needed and wastes produced - thus the impact (I) is the product of these three factors (P x A x T) I = P x A x T
Ex: Impact of CO2 emissions by automobile is based on • P = amount of people with cars • A = number of cars per person • T = amount of CO2 per car - the level of impact varies based on these three factors and continuous fluctuate based on usage and trends Ex: SUV’s and Hybrid cars
ENVIRONMENTAL SUSTAINABILITY - one of the goals of environmental science is to develop and educated people in the ways of environmental sustainability • Sustainability: indefinite use of the environment in a manner that it’s quality does not decline – needs of the human population are met without endangering the welfare of future generations • Sustainability avoids the Tragedy of the Commons
Tragedy of the Commons - Its not my land, why should I clean it up? - I didn’t make the mess, why should I bother? - Its not going to hurt me, why should I care? • lack of communal responsibility, lack of foresight, lack of a sense of stewardship
- when there is no sense of ownership or responsibility, the effort to care for a resource is diminished – thus when a large number of people use the resource (a common resource) without the sense of stewardship (care and sustaining), the common resource will degrade and be unavailable for future use Ex: Generate lots of air pollution now – affect future generations Don’t recycle – impacts availability of resources
Need Stewardship – shared responsibility for the use and care of the resources of the planet – not for exploitation but a protective and sustainable approach to using the resources and developing new and better ways of meeting our needs Role of Government: Regulate and Control the use of Resources Ex: Fish and Game Commission