AP Environmental Science

Intro: Toward a Sustainable Future

Easter Island

Easter Island

Barren Land

Beautiful land

Lessons of Easter Island

• Maybe we will never know the whole story of what happened to the Rapanui people

• We know we (humans) can impact the environment

• Sometimes our impact has unintended consequences

• Populations change, and can increase beyond our carrying capacity

Carrying Capacity

• Carrying capacity refers to the number of individuals who can be supported in a given area within natural resource limits, and without degrading the natural social, cultural and economic environment for present and future generations.

• The carrying capacity of a biological species in an environment is the population size of the species that the environment can sustain indefinitely, given the food, habitat, water and other necessities available in the environment.

Sustainability

• Sustainability is the capacity to endure.– In ecology the word describes how biological

systems remain diverse and productive over time.– Diverse populations are healthy and better able to

adapt to environmental stress

Changes in carrying capacity• The carrying capacity for any given area is not

fixed. • It can be altered by improved technology,

allowing more access to resources or better maintenance of supplies– Refrigeration– Water treatment

• but it is changed for the worse by pressures which accompany a population increase.

Changes in Carrying Capacity

• As the environment is degraded, carrying capacity actually shrinks, leaving the environment no longer able to support even the number of people who could formerly have lived in the area on a sustainable basis

Beyond the carrying capacity

• Population increases beyond carrying Capacity of the given land result in increased rate of death and disease – because of inadequate food or water supply– Improper sanitation– Inadequate shelter

The Global Environmental Picture

Population

• Human population is over 6.9 billion (2010)• Has grown by 2 billion in the last 25 years• Growing by over 74 million people/year• UN pop division estimates 9.1 billion by 2050!

– Remember these are estimates– Remember bias!

Ecosystems

• In decline around the world• Ground water supplies are depleted• Agricultural Soils degraded• Oceans overfished• Forests cut faster than they can regrow• 60% of global ecosystems are being degraded

or used unsustainably (Millennium Ecosystem Assessment)

EcosystemsThe diversity of organisms in an ecosystem provides

essential foods, medicines, and industrial materials.– As many as 40 percent of modern pharmaceutical

medicines in the developed world are derived from plants or animals

– biological resource ,especially forests ,provide wildlife habitat and recreational opportunities, prevent soil erosion and flooding, help provide clean air and water.

– Biological resources are also important biotic checks to pests and diseases and serve as defense line against global climate change.

Ecosystems

• Reduction in biodiversity– Less variety of species in ecosystems around the

globe• Why?

– Invasive species– Human population growth– Rainforest deforestation– Pollution

BiodiversityThese results point to reduced biodiversity through competition, nutrient enrichment and a milder climate. •Change in the percentage of 785 species native to Scotland, by habitat between the 1950s and 1987-1999 (Preston et al., 2002).

Ecosystems• In decline • As mountain forests disappear, less rain falls, less

snow is made, • land drains morequickly, • soil temperatures rise.

The increased fire threat and loss of nearly half of the sagebrush steppe in the Great Basin has resulted in:•millions of taxpayer dollars spent annually for fire fighting and restoration, •an increased threat to property and life, •increased soil erosion and sedimentation, •decreased water quality, •a decline in the forage base for domestic livestock, • decreased habitat for big game and threatened species of wildlife.•The continued expansions of exotic weeds, woodlands, and human populations throughout the Intermountain West will

•greatly increase economic losses due to costs of fighting wildland fire and restoration efforts.

International Initiatives• Montreal protocol (1987)

– because of concern about ozone depletion in the stratosphere

– Action aimed at reducing pollution from release of chlorofluorocarbon refrigerants into the atmosphere

• Kyoto Protocol (1997)– Because of concern about greenhouse gas emissions– 166 nations to reduce CO2and other greenhouse

gasses to pre 1990 levels by 2010– Ratified by 169 countries (not ratified by the US or

most developed countries)

1) Sustainability2) Stewardship3) Science

Three Strategic Themes

Strategic Theme 1-Sustainabilitya) Sustainable Systems: can continue indefinitely

without depleting any material or energy in the system in order to keep it running.

– ex. fish or trees; harvested at the rate of reproduction and growth

Sustainability cont.b) Sustainable Society: in balance with the

natural world through generations, not harvesting or polluting more that can be easily absorbed by the system

Sustainability cont.

C) Sustainable Development: a form of development that meets present needs without compromising the ability of future generations to meet their needs

– balance to maintain and improve the wellbeing of people and the environment.

• industrial countries- are more concerned about environmental sustainability

• developing countries- are more concerned about economic development

Transition to SustainabilitySteps1) Stabilize Human Population2) Develop economy that relies on natures income, and

protects ecosystem capital from depletion3) Technological transition from pollution-intensive

production to environmentally benign production4) Political and Social transition to those that embrace

stewardship approach to peoples needs (eliminate large scale poverty) !:P

5) Transition from car dominated urban sprawl to smart growth concepts

Smart Growth Concepts

• Smart growth is an urban planning and transportation theory that concentrates growth in the center of a city to avoid urban sprawl; and advocates compact, transit-oriented, walkable, bicycle-friendly land use, including neighborhood schools, complete streets, and mixed-use development with a range of housing choices.

Complete Streets

Mixed Use Development

Sustainable Development• Smart growth values long-range, regional

considerations of sustainability over a short-term focus. – Its goals are

• to achieve a unique sense of community and place;• expand the range of transportation, employment, and

housing choices; • equitably distribute the costs and benefits of development; • preserve and enhance natural and cultural resources; • promote public health.

Strategic Theme 2:Stewardship

• Stewardship Ethic: what is right and wrong as they apply to caring for the natural world and the people on it

Stewardship cont.Issues to grapple with:1) What is the "common good" where conflicting needs

exist? – ex. economic need vs. health of ecosystem

2) How do we balance the needs of the present with needs of the future?

3) Balancing species preservation and individual property rights

4) Gathering public support for aid of others5) Consumption limits vs freedom to choose lifestyle or

individual environmental rights and responsibilities vs those of the community

Science• Scientific method or process

ScienceChallenges of data collection while investigating

environmental science issues1) very complex systems in the environment2) new observations- take time to test claims,

allowing disagreement to continue3) Bias- promoting agendas4) Subjective values- deals with human

response to environmental issues- relative risk vs. benefit

Evaluating Science

1) Evaluate the data supporting theory, can it be confirmed?

2)Are the conclusions rational, do the explanations follow from the data?

3) Does the explanation account for all of the observations – objectivity?

4) Do the evaluators have any reason to favor an explanation? Who gains from it?

5) Is the conclusion supported by "community of scientists" with competence to judge the work?

Three Integrative Themes1. Ecosystem Capital: the sum of goods and

services provided by ecosystems, free of charge, both managed and natural.

2. Political Policy: Human management decisions as they apply to the natural world.

3. Globalization: the interconnectedness of all human activities, ideas, and cultures.

Ecosystem Capital• The world economy depends on natural resources

– Freshwater– Food– Fuel– Raw materials; wood, leather, cotton and fur

• Agriculture, forestry and fishing are responsible for:– 50% of all jobs worldwide– 70% of all jobs in Sub-Saharan Africa, eastern Asia and

the Pacific Islands

Ecosystem Capital• Provides flow of services such as:

– The breakdown of waste– Erosion control– Climate regulation– Pest management– Maintenance of crucial nutrient cycles

• It’s income generating capacity represents a major form of national wealth.

• Protection of this capacity is essential to ensure those goods and services are available year after year.

Protecting Ecosystem Capital

• Millennium Ecosystem Assessment– 15 out of the24 ecosystem services they examined

are being degraded or used unsustainably• Pollution of air and water• Invasive species• Wetlands drained

• Market forces can drive exploitation– Construction increases timber use– Over fishing to sustain a community

Overall Goal• The production of a sustainable future for the

global community.

The Environment in the 21st Century• World Summit on Sustainable Development (WSSD) 2002

South Africa– Sponsored by UN– Tried to address weak implementation of the agreements made

at the U.N. Conference on Environmental Development 1992• These included:

– Agenda 21- blueprint to guide sustainable dev.– Conventions on climate change and biodiversity– Forest principle statement– Commitment to double funding to help developing countries

– Minimal success – Successful in committing to provide basic sanitation to 50% of

those in need by 2015, restore ocean fisheries by 2015 and reduce the rate of loss of biodiversity by 2010

– Evidence that the world is very divided on key issues

Global Divide on Issues

• Corporate accountability• Globalization (economically)• Trade• Energy policies• Climate change• Development priorities• Financial aid

The Good News

• Food production has improved the nutrition of millions in the developing world

• Life expectancy is rising• Malnourishment % is declining• Pop growth is declining in dev. Countries• Pollution load in industrialized countries has

decreased significantly• More people are involved in protecting the

environment

More Good News!

• Evidence suggests that environmental degradation can be slowed down and even reversed

• People are being freed from hunger and poverty

• People can learn to conserve and are doing that.