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THEMATIC FOCUS
THEMATIC FOCUS
Humans and the Environments
Humans and the Environments
The environment shapes human societies, and as populations grow and change, these populations in turn shape their environments.
LEARNING OBJECTIVE
Explain the causes and effects of environmental changes in the period from 1900 to present.
HISTORICAL DEVELOPMENTS
KC-6.1.II.A As human activity contributed to deforestation, desertification, a decline in air quality, and increased consumption of the world’s supply of fresh water, humans competed over these and other resources more intensely than ever before.
KC-6.1.II.B The release of greenhouse gases and pollutants into the atmosphere contributed to debates about the nature and causes of climate change.
ILLUSTRATIVE EXAMPLES
Impacts of human activity
§ deforestation
§ desertification
§ decline in air quality
§ increased consumption of the world’s supply of fresh water
Debate over climate change
§ release of greenhouse gases and pollutants into the atmosphere
Impacts of human activity
Impacts of human activity
§ deforestation
§ deforestation
Human-driven and natural loss of trees—deforestation—affects wildlife, ecosystems, weather patterns, and even the climate.
Forests cover about 30 percent of the planet's land mass, but humans are cutting them down, clearing these essential habitats on a massive scale.
Between 1990 and 2016, the world lost 502,000 square miles (1.3 million square kilometers) of forest, according to the World Bank
Approximately 17% of the Amazonian rainforest has been cut down between 1965-2015
Causes of deforestation
Farming, grazing of livestock, mining, and drilling combined account for more than half of all deforestation
In Malaysia and Indonesia, forests are cut down to make way for producing palm oil plantations (used to make shampoos, potato chips, saltines, etc.)
In the Amazon, cattle ranching and farms—particularly soy plantations
Logging operations -- which provide the world’s wood and paper products and home building
urban sprawl -- as a result of increased population growth.
Implications:
climate change -- cutting trees both adds carbon dioxide to the air and removes the ability to absorb existing carbon dioxide
global water cycles -- loss of clean water and biodiversity from all forests could have many other effects we can’t foresee
Removing tree canopy -- blocks the sun’s rays during the day and retains heat at night. That disruption leads to more extreme temperature swings that can be harmful to plants and animals
loss of habitat -- 80% of earths land animals and plants live in forests
subsistence and income -- 250 million people depend on forests for survival. Many of whom are the world's rural poor.
§ desertification
§ desertification
human-caused land degradation in areas with low or variable rainfall known as drylands: arid, semi-arid, and sub-humid lands
These drylands account for more than 40 percent of the world's terrestrial surface area.
Causes:
According to the United Nations, land degradation has occurred throughout history, but the pace has accelerated, reaching 30 to 35 times the historical rate
urbanization, mining, farming, and ranching
Climate change also plays a significant role, increasing the risk of drought, as a result of changing weather patterns
Implications:
About 2 billion people live on the drylands that are vulnerable to desertification
threatens to displace an estimated 50 million people by 2030
locations of most concern:
Uzbekistan and Kazakhstan surrounding the Aral Sea
Africa's Sahel region, bordered by the Sahara Desert to the north and savannas to the south
northern China
§ decline in air quality
§ decline in air quality
heavy dependence on fossil fuels has increased air pollution in many major cities.
1970s -- traffic police in Tokyo frequently wore face masks
Mexico City, officials estimated in 2002 that air pollution killed 35,000 people every year
§ increased consumption of the world’s supply of fresh water
§ increased consumption of the world’s supply of fresh water
Industrial pollution in the Soviet Union rendered about half of the country’s rivers severely polluted by the late 1980s
20 percent of Russias population lived in regions defined as “ecological disasters.”
Debate over climate change
Debate over climate change
§ release of greenhouse gases and pollutants into the atmosphere
§ release of greenhouse gases and pollutants into the atmosphere
Although considerable disagreement existed about the rate and likely consequences of this process, concern about melting glaciers and polar ice caps,rising sea levels,thawing permafrost,extreme hurricanes, further species extinctions, and other ecological threats punctuated global discussion of this issue.
It is clearly a global phenomenon (very few argue that change is not occurring) and, many people have been demanded global action
Environmentalism began in the nineteenth century as Romantic poets such as William Blake and William Wordsworth denounced the industrial era’s “dark satanic mills,” which threatened the “green and pleasant land” of an earlier England.
The Annual Greenhouse Gas Index (AGGI) in 2019 was 1.45, which means that we’ve turned up the warming influence by 45% since 1990
It took ~240 years for the AGGI to go from 0 to 1, i.e., to reach 100%, and 29 years for it to increase by another 45%
In terms of CO2 equivalents, the atmosphere in 2019 contained 500 ppm, of which 410 is CO2 alone. The rest comes from other gases.
CO2 is by far the largest contributor to the AGGI in terms of both amount and rate of increase
Note: The IPCC suggests that a constant concentration of CO2 alone at 550 ppm would lead to an average increase in Earth’s temperature of ~3°C (5.4°F).
second-wave environmentalism
began in the West with the publication in 1962 of Rachel Carson’s Silent Spring
an exposure of the chemical contamination (DDT) of the environment that threatened both human health and the survival of many other species
She wrote of a “strange stillness” in a world where the songs of birds might no longer be heard.
The book touched a nerve, generating an enormous response and effectively launching the environmental movement in the United States
early 1990s -- some 14 million Americans, one in seven adults, had joined one of the many environmental organizations—national or local—that aimed much of their effort at lobbying political parties and businesses
Green Party
originated with the German environmental movement
activists directly entered the political arena
One of the Greens’ main concerns was opposition to nuclear energy
Chikpo (“tree-hugging”) movement in India
sought to protect the livelihood of farmers, artisans, and herders living in areas subject to extensive deforestation
fought to prevent or limit the damming of India’s Narmada River derived from the displacement of local people
similar anti-dam protests in the American Northwest were more concerned with protecting salmon runs
Philippines -- environmental activists confronting the operation of foreign mining companies have sought fundamental changes in the political and social structure of their country
Changing Points of View on DDT
“The stance of the panel, led by a University of California epidemiologist, is likely to be controversial with public health officials. Use of DDT to fight malaria has been increasing since it was endorsed in 2006 by the World Health Organization...Malaria is one of the world's most deadly diseases, each year killing about 880,000 people, mostly children in sub-Saharan Africa, according to the World Health Organization.”
Source: Should DDT Be Used to Combat Malaria? Scientific American. May 4, 2009
John Stossel and Richard Tren detail how the DDT ban, a great victory for environmentalism, has led to a multitude of deaths throughout the world
CLASS ACTIVITY -- SAQ (Impacts of human activity)
CLASS ACTIVITY -- SAQ (Impacts of human activity)
Activity: read the following passage and fully answer all the questions.
Source: John R. McNeill, historian, Something New Under the Sun: An Environmental History of the Twentieth-Century World, 2000.
“The health consequences of air pollution in the twentieth century were gargantuan, although hard to measure precisely. By 1992, according to one World Bank estimate, air pollution in the world’s cities killed 300,000 to 700,000 people a year (car crashes killed about 880,000 a year). In 1996, the Harvard School of Public Health put the figure at 568,000 a year. In 1997, the World Health Organization estimated that all air pollution killed 400,000 people worldwide annually. Taking the lower figure, and assuming a) that at-risk urban populations quadrupled since 1950 and b) that the increasing lethality of air pollution in China, the Third World, and the Soviet bloc offset the air quality improvements in Japan, Western Europe, and the United States, I reckon that air pollution killed about 20 million to 30 million people from 1950 to 1997. For the twentieth century as a whole the figure would be only a bit larger because urban populations were smaller in the first half of the century, although in the Western world air pollution was worse. All told, a ‘guesstimate’ for air pollution’s twentieth-century toll would be 25 million to 40 million, roughly the same as the combined casualties of World Wars I and II, and similar to the global death toll from the 1918–1919 influenza pandemic, the twentieth century’s worst encounter with infectious disease.”
a) Identify ONE major claim that John McNeill advances in the passage regarding the historical significance of air pollution in the late twentieth century.
b) Explain ONE way in which economic developments in the late twentieth century led to the environmental effects outlined in the passage.
c) Based on the passage, explain ONE significant limitation of John McNeill’s efforts to assess the overall toll of air pollution on human societies in the late twentieth century.
DEBRIEF AND SUMMARY
DEBRIEF AND SUMMARY
Key Takeaways
A.) Ability to exploit the world's resources and our levels of consumption has increased dramatically in the past century
amazing new ability of humankind to tap the energy potential of fossil fuels—coal in the nineteenth century and oil in the twentieth
Hydroelectricity, natural gas,and nuclear power added to the energy resources available to our species
B.) Global Population as a Contributing Factor
quadrupling of the world’s population in a single century
growing numbers of the poor and the growing consumption of the rich led to the doubling of cropland and a corresponding contraction of the world’s forests and grasslands
human remaking of the environment also greatly increased the population of cattle, pigs, chickens, rats, etc.
C.) Environmental Movements in the Global South has a vastly different perspective than in the Industrialized world.
An average North American in the 1990s, used 50 to 100 times more energy than an average Bangladeshi
A Malaysian official put the dispute succinctly:“The developed countries don’t want to give up their extravagant lifestyles, but plan to curtail our development.”
Indian environmentalist Vandana Shiva said, “The threat to the atmospheric commons has been building over centuries, mainly because of industrial activity in the North.Yet...the North refuses to assume extra responsibility for cleaning up the atmosphere. No wonder the Third World cries foul when it is asked to share the costs.”
D.) Timeline of Earth’s Average Temperature (20,000BCE-Present)
The Anthropocene--A new epoch, not formally accepted by geologists, during which our species has become the dominant force for change in the biosphere. The Anthropocene marks the end of the Holocene epoch, about the time of the Industrial Revolution, 200 years ago.
(the state of human domination over the planet, which has drastically altered the Earth from its pre-industrial condition, warranted the name change. Anthropo is the Greek root for “human.”)
Unit 9.3 - Technological Advances: Debates About the Environment After 1900
Unit 9.3 - Technological Advances: Debates About the Environment After 1900
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