chapter 2 global environment 2013

The Changing Global Environment

The Human-Environmental Relationship

Chapter/Module 2

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Learning Objectives

Learn the basics of Earth’s environmental systems to prepare for later chapters

Understand the following concepts, models, and terms:

Anthropogenic

Climograph

Köppen climate system

Climatic factors

Greenhouse effect

Climate Change

Green Revolution2

Global Climates and Humans

Human settlement and food production are closely linked to local patterns of weather and climate– People in different parts of the world adapt to

weather and climate in different ways– Climate links us together in our globalized

economyOpportunitiesHardshipsChallenges in growing food3

Plate Tectonics

Move in 2 directions– Convergent– Divergent

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Global Tectonic Plates

5It is on the margins of these plates that the most interactions happen, thus they are most geologically active as well.

Convection powers plate tectonics

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African Rift Valley

Example of Divergent Plate Boundaries

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Global Hazards

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Hazards

Many of the world’s hazards are located near boundaries of tectonic plates: – Earthquakes and tsunamis– Eruptions– Flooding

Others are not:– Hurricanes– Tornadoes

Either way, Humans are always vulnerable to their environments.

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TAKE QUIZ 2.1

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Weather v. Climate

Weather– Daily– Particular time– Particular place

Climate– Long term average conditions of a place, based

on at least 30 years worth of data.

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Climate—Factors

1. Insolation

2. Latitude

3. Land/water contrast—continentality

4. Altitude

5. Pressure systemsa. Ocean currents

b. Wind systems

6. Local topography

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Climograph:

provides information on average high and low temperatures and precipitation for every month in a year– Graph includes these components:

Average high temperature (upper line) Average low temperature (lower line) Average precipitation (bars)

– Provides “Average Annual Precipitation”

Climate Factor 1: Insolation

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Stands for incoming solar radiation: Energy from the sun heats the earth’s surface unevenly.

Climate Factor 2: Latitude

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Distance from the earth’s equator. Poles have less insolation and equator has more insolation.

Climate Factor 3: Contientality

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Rule of contientality: The interiors of the continents have more climatic extremes and the coasts have milder climates.Land v water deals with insolation differently.

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Here, two cities at the same latitude have different climates because San Diego is on the coast, and Dallas is on the interior of the continent it has warmer summers and cooler winters.

Climate Factor 4: Pressure systems

18 a. Ocean currents: redistribute energy and isolation

Climate Factor 4: Pressure systems

19b. Global wind patterns. Wind moves from areas of high pressure to low pressure.

Topography

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Topo=surface variations

Graphic delineation in detail usually on maps or charts of natural and man-made features of a place or region especially in a way to show their relative positions and elevations.

Local variations on the earth surface can impact the weather and climate at a smaller scale.

Climate

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Classifying climates is not a new idea. This is how the ancient Greeks understood the world.

Köppen Climate Classification

A Tropical, wet climates B Dry climates, desert and steppe C Mild midlatitude—Mediterranean D Continental Midlatitude climates E Polar H Highland

There are also many subclassificationsthat further delineate climate types, ex. Cfa 22

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25 B climate. Sahara Desert in Morocco.

26A C climate. Gibraltar, a British outpost on the tip of Spain, and entrance to the Mediterranean.

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Examples of a D climate in Alaska, USA.

TAKE QUIZ 2.2

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Global Climate change

More that the Greenhouse effect– Human activities connected with economic

development and industrialization affect the world’s climate

Anthropogenic (human-caused) pollution increases the natural greenhouse effect

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The debate on Climate change

Watch the three following videos on this topic:

James Hansen 2012– How long have scientists been studying climate change?

Rachael Pike 2009– Is there consensus among the scientific community?

Vicki Arroyo 2012– What is the relationship between humans, hazards and

daily life? Is there hope? – What is stationarity?

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– Computer models and scientists are coming to agreement on effects

Average global temperatures will increase 2 °F to 4 °F by 2030

– The same amount of cooling caused the Ice Age Major shift in agricultural areas

– Wheat belt could become warmer and drier; lower grain yield– Canada and Russia could become warmer– Southern regions of the U.S. and Europe could become warmer and

drier, requiring irrigation Rising sea levels as polar ice-caps melt, endangering low-

lying islands around the world, and coastal areas elsewhere

Effects of Global Warming

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Rio de Janiero Earth Summit (1992)

First international agreement on global warming

167 countries agreed to reduce their greenhouse gas emissions by a specific target date

– U.S., Japan, India, China failed to meet emissions reductions

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Kyoto Protocol (Dec 1997)

38 industrialized countries agreed to reduce their emissions of greenhouse gases to below 1990 levels

To take effect, countries emitting 55% of the world’s greenhouse gases must ratify it

Ratification of Kyoto Protocol will be difficult– Large developing countries (India, China) are not yet

bound to reduce greenhouse gases, and would have an advantage

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Trends in Global Temperatures

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Historic record of climate change

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Human Impacts on Plants and Animals: The Globalization of Nature

Earth is unique because of the rich diversity of plants and animals

Vegetation is the “green glue” that binds together Earth’s life and atmosphere– Vegetation is both a product of and an influence on

climate, geology, and hydrology Humans play a big part in this interaction

– Domestication of plants, animals– Changed natural pattern of vegetation on the land

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Land degradation

Human (anthropogenic) – Keep track of these in each chapter

Natural disasters +

human influence

and choice

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GREEN REVOLUTION

THE SUCCESSFUL DEVELOPMENT OF HIGHER YIELD, FAST-GROWING VARIETIES OF RICE AND OTHER CEREALS IN DEVELOPING COUNTRIES– International research program-1960s– Focused on the food crisis.– Increased production per unit area via:

Miracle cropsNew irrigation systemsIntensive use of fertilizersSalinization of irrigated areas

– Second stage has evolved since 1970s New types of fast-growing wheat and rice specifically bred

for tropical and subtropical climates With irrigation, fertilizers and pesticides, farmers can grow

two or three crops each year instead of just one India doubled its food production between 1970 and 1992

– Problems associated with Green Revolution 400% increase in use of fossil fuels makes Green

Revolution agriculture more vulnerable to oil price fluctuations

Environmental damage Social costs, especially associated with the higher cost of

this approach

The Green Revolutions

– Local and regional problems are usually responsible for food unavailability

Poverty and civil unrest at local levels impede food distribution

– Political problems are usually more responsible for food shortages than are natural events

Food distribution is highly politicized– Globalization is causing a worldwide change in food

preferences Shifting from vegetarian to meat-based diet could have

profound implications– Africa and South Asia are most threatened by food

shortages

Problems and Projections

TAKE QUIZ 2.3

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