chapter 2 global environment 2013
TRANSCRIPT
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.
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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