ENVIRONMENTAL SCIENCECH.1

“our changing environment”

THE BIG PICTURE

Human population Earth’s natural resources pollution in air, water, or soil and harms humans or other living organisms.

How can humans impact the environment less?

Env. Sci. is the study of the relationship between humans and the environment (both biotic and abiotic factors)

It is interdisciplinary - science (ecology, chemistry, agriculture) and social sciences (geography, populations, politics, economics, ethics)

Are there solutions to all environmental problems? All solutions have consequences for

someone/something/organism

TYPES OF ENVIRONMENTAL ISSUES

List any 5 environmental issues that you can think of and identify if you think it is a global, regional, or local issue.

ENVIRONMENTAL SOLUTIONS

No perfect – there’s a cost (may/maybe not financial) for everything

All about BALANCE and TRADE-OFFS: cost v. benefit

Examples – setting aside park reserves for animals by uprooting people, switching to wind/solar energy hurts the economic gain of oil companies, eggs of free-range chickens cost more money

THE ENVIRONMENT (EARTH) Life has existed on earth for 3.8 billion years Earth well suited for life

Water covers ¾ of planet Habitable temperature Moderate sunlight Atmosphere provides oxygen and carbon dioxide Soil provides essential minerals for plants

But humans are altering the planet; not always in positive ways

WHAT IS THE SIGNIFICANCE?

1999 – 6 billion 1987 – 5 billion 1975 – 4 billion 1960 – 3 billion 1930 – 2 billion 1800 – 1 billion

HUMAN IMPACTS ON ENVIRONMENT- POPULATION

Earth’s Human Population is 7 billion Growing exponentially

Increase will adversely affect living conditions in many areas of the world

POPULATION

Globally, 1 in 4 people lives in extreme poverty Cannot meet basic need for

food, clothing, shelter, health Difficult to meet population

needs without exploiting earth’s resources

GAP BETWEEN RICH AND POOR

Highly Developed Countries (HDC) Complex industrialized bases, low population

growth, high per capita incomes Ex: US, Canada, Japan

Less Developed Countries (LDC) Low level of industrialization, very high fertility

rate, high infant mortality rate, low per capita income

Ex: Bangladesh, Mali, Ethiopia

TYPES OF NATURAL RESOURCES

OVERPOPULATION

People overpopulation Too many people in a given geographic area Problem in many developing nations (like Nigeria

and India) Consumption overpopulation

Each individual in a population consumes too large a share of the resources

Problem in many highly developed nations (like US)

WHAT IS THE SIGNIFICANCE?

1999 – 6 billion 1987 – 5 billion 1975 – 4 billion 1960 – 3 billion 1930 – 2 billion 1800 – 1 billion

WORTH REVISITING…

¼ have no access to clean water/live in extreme poverty

Why does this matter? And what’s the solution? Reduces life expectancy, increased illiteracy,

insufficient access to health services, safe water and balanced nutrition.

Ecological problem - how to feed all these people without destroying ecosystems

Current birth rate – 3 per family Solution = family planning

ECOLOGICAL FOOTPRINT The average amount of land, water and ocean

required to provide that person with all the resources they consume

Earth’s Productive Land and WaterEarth’s Productive Land and Water 11.4 billion 11.4 billion hectareshectares

Amount Each Person is Allotted Amount Each Person is Allotted (divide Productive Land and Water (divide Productive Land and Water by Human Population)by Human Population)

1.9 hectares1.9 hectares

Current Global Ecological Footprint Current Global Ecological Footprint of each personof each person

2.3 hectares2.3 hectares

ECOLOGICAL FOOTPRINT COMPARISON

IPAT MODEL Measures 3 factors that affect environmental

impact (I)

I = P A TI = P A T

Environmental Environmental ImpactImpact

Number Number of peopleof people

Affluence per person Affluence per person (consumption of (consumption of

resources)resources)

Environmental effect of Environmental effect of technologies used to technologies used to

get/consume resourcesget/consume resources

ENVIRONMENTAL SUSTAINABILITY The ability to meet current human need for natural

resources without compromising the needs of future generations

Requires understanding: The effects of our actions on the earth That earth’s resources are not infinite

SUSTAINABLE DEVELOPMENT Economic development that meets the needs of the

present generation without compromising future generations

EXAMPLES OF HUMAN IMPACT ON THE ENVIRONMENT

Endocrine disrupters Ex: many chlorine containing compounds (PCBs and

dioxins), lead, mercury, DDT, phthalates Overfishing

Closed Georges Bank fishery due to low fish #s Results: lost jobs, more regulation (Magnuson-

Stevens Fishery conservation and Management Act) Declining Bird populations

Losing habitat, forest fragmentation (increases forest edge), nest parasitism (ex. Cowbirds)

Reintroducing Wolves to Yellowstone To restore ecosystem and remove wolf from

endangered species list, opposed by farmers/ranchers

Introduction of Invasive species Ex: ballast water, zebra mussels Common traits: good food supply, no predators, high

reproductive rates Stratospheric Ozone depletion

CFCs (stable!) from cooling agent Freon in refrigerators, air conditioners, aerosol propellants

Global Climate Warming/Increasing Carbon dioxide Levels CO2 from burning fossil fuels and burning forests Kyoto Protocol

Destroying Tropical Rain Forests For agriculture and pasture Ex: Amazon in Brazil Destroys habitat for organisms (ex songbirds),

erosion into local water, loss of filtration and water flow regulation, CO2