Unit 5: Human-Environment Interactions

In this unit, we will explore how humans interact with their environment and the

consequences of those interactions. In particular, we will focus on the following

questions:

1. How do humans create and address global environmental problems?

2. How can environmental changes in one location become a global issue?

3. How does energy production and distribution affect the environment?

4. How does the distribution and utilization of natural resources influence the ways

societies interact?

Earth provides enough to satisfy every man’s needs, but not every man’s greed.

--- Mahatma Ghandi

Mahatma Ghandi (1869-1948) was the leader of the Indian independence movement

and it credited for inspiring movements for civil rights and freedom across the world.

What do you think he meant by the statement above?

Unit 5: Human-Environment Interactions

(Lesson 1)

How Do Humans Interact with the Environment?

In the previous unit, we explored the idea of

culture and how culture is often influenced by the

resources people have available. We also looked

at how cultures adapt to their surroundings, or

their environment. Cultural landscapes are the

result of humans interacting with their

environment. Buildings, bridges, cell towers, and

other human features in the environment make up

cultural landscapes.

Human-environment interaction is one of the five

themes of geography. Humans interact with their

environments in one of three ways. They can:

• use the resources of the environment, such as cutting down trees for homes;

• modify the environment, such as building cities and towns; or

• adapt to the environment, such as wearing heavy coats in the winter and heating

homes.

Human-environment interactions take place at all spatial scales from the local to the

global. Locally, we change the cultural landscape when we build homes, cultivate

farmland, or remove oil and gas from the earth. Sometimes, these human-

environment interactions at the local level lead to global problems. Global problems

such as climate change, deforestation, pollution, and resource depletion can be

investigated through the geographic theme of human-

environment interaction.

Take a look at the picture on the right. What is out of

place? What used to be a thriving, active waterway

has become a boat “graveyard” of sorts. How do you

think this happened? The answer is simple –humans

interacted with their environment!

The Shrinking of the Aral Sea

Below is a map of Central Asia. It shows the location of the Aral Sea on the border of

Kazakhstan and Uzbekistan.

The photographs below were taken of the Aral Sea at two different times. The one on

the left was taken in 2000, while the other was taken in 2012. Human-environment

interaction explains what caused the Aral Sea to shrink.

The Aral Sea

2000

The approximate

shoreline in 1960

2012

In the 1960s, the Soviet Union controlled the region that is currently Kazakhstan and

Uzbekistan. The Soviets undertook a major water diversion project on the arid (dry)

plains of Kazakhstan, Uzbekistan, and Turkmenistan. The region’s two major rivers

were used to transform the desert into farms for cotton and other crops. Before the

water diversion project, the rivers flowed down from the mountains and finally pooled

together in the lowest part of the basin. The lake they made, the Aral Sea, was once

the fourth largest in the world.

The water that was diverted for irrigation made the desert bloom. However, it

devastated the Aral Sea. By 2000, the lake was already a fraction of what it was in

1960. As the lake dried up, fisheries and the communities that depended on them

collapsed. The increasingly salty water became polluted with fertilizer and pesticides.

The blowing dust from the exposed lakebed, contaminated with agricultural chemicals,

became a public health hazard. The salty dust blew off the lakebed and settled onto

fields, degrading the soil. Croplands had to be flushed with larger and larger volumes

of river water. The loss of the moderating influence of such a large body of water made

winters colder and summers hotter and drier.

Global Issues Tied to Human-Environmental Interactions

Several environmental global problems can be seen in the Aral Sea issue:

• Diversion of rivers

• Soil damage

• Climate change

• Pollution

• Water shortages

Beginning in 1973, the United Nations Environmental Program (UNEP) has promoted

World Environment Day each year to draw attention to global environmental problems.

A different theme based on a global environmental issue is chosen each year. Below is

a chart showing different global problems that have been selected over the years.

What global problem was the focus of the

year? What is one reason it is a global problem?

2004 Ocean pollution More than 70 percent of the world´s marine fisheries are fished up to or beyond their sustainable limit.

2005 Loss of green space in cities When roads and buildings replace natural land cover, urban air temperatures can exceed those of the surrounding countryside by as much as 41

ºF (5

ºC).

2006 Desertification and other dry land issues The consequences of desertification and drought include food insecurity, famine and poverty.

2007 Effects that climate change was having on polar ecosystems and communities

Climate change can cause rising sea levels that can affect low lying coasts and islands.

2008 Greenhouse gas emissions Greenhouse gas emissions have led to climate change.

2009 Climate change Globally, there will be more extreme weather including drought, flooding, disruption and destruction of plant and animal species.

2010 Biodiversity A total of 17,291 species are known to be threatened with extinction.

2011 Destruction of forests We need trees because they play a key role in our battle against climate change.

2012 How a Green Economy can help lower environmental risks

We have a lot of environmental problems that could be reduced with a Green Economy.

2013 Food waste and food loss Every year 1.3 billion tons of food is wasted.