APWH Unit 9.3

Unit 9.3 — Technology and the Environment（1900–Present）

Essential Question:
What were the causes and effects of environmental changes from 1900 to the present?

One-glance Review

• Population growth → Increased demand for land, food, and water

• Urbanization → Produced more waste and intensified pressure on soil and water

• Industrialization and globalization → Expanded pollution and resource extraction

• Deforestation / Desertification → Damaged ecosystems and reduced productive land

• Water Scarcity → Worsened inequality, especially for women and children

• Global Warming → Prompted international debate and environmental activism

• Renewable Energy → Developed as an alternative to Fossil Fuels

• Kyoto Protocol / Paris Agreement → Represented efforts at global climate cooperation

• Anthropocene → Reflected the idea that humans now shape Earth’s environment on a planetary scale

Core Ideas

Human Activity and Environmental Change

• Since 1900, agricultural, industrial, and commercial expansion has caused major environmental changes:

  • Deforestation

  • Desertification

  • declining Air Quality

  • growing use of fresh water

  • rising greenhouse gas emissions

• These changes intensified competition for scarce resources and pushed environmental issues into global politics.

The modern era brought both economic growth and severe environmental consequences.

KEY TERMS BY THEME

CULTURE: Movements and Organizations

• Green Party

• Green Belt Movement

• Club of Rome

• Greta Thunberg

• Extinction Rebellion

ENVIRONMENT: Scientific Studies and Concepts

• Deforestation

• Desertification

• Air Quality

• Greenhouse Gases

• Fossil Fuels

• Water Scarcity

• Renewable Energy

• Global Warming

• Carbon Footprint

• Anthropocene

GOVERNMENT: International Agreements

• Kyoto Protocol

• Paris Agreement

LEADERS / THINKERS

• Ban Ki-moon

• Greta Thunberg

1. Environmental Changes Since 1900

Major Problems

Since the 20th century, human activity contributed to several major environmental problems:

• Deforestation — cutting down forests so land could be used for agriculture
  森林砍伐

• Desertification — loss of natural vegetation through overuse of dry lands
  荒漠化

• declining Air Quality — worsening air conditions caused by pollutants
  空气质量下降

• increased use of fresh water — greater pressure on limited water supplies
  淡水消耗增加

Climate as a Global Problem

• Scientists observed that Earth was getting warmer

• Leaders such as Ban Ki-moon argued that climate change was a global challenge

• This meant environmental issues increasingly required international cooperation rather than just national action

2. Causes of Environmental Change

Population Growth

• World population increased dramatically:

  • 1900 → 1.6 billion

  • 1950 → 2.55 billion

  • 2000 → 6.12 billion

• More people meant:

  • more food demand

  • more cropland

  • more water use

• This led to:

  • Deforestation

  • soil erosion(土壤侵蚀)

  • shrinking habitats(栖息地缩小)

Urbanization

• The growth of cities intensified environmental stress

• By 2025, an estimated 5.1 billion people would live in cities

• Urbanization increased:

  • waste production

  • water pollution

  • pressure for intensive farming(集约农业)

  • forest clearing

Globalization and Industrialization

• As industrialization spread to developing countries:

  • demand for energy and raw materials increased

  • manufacturing expanded pollution

  • growing middle classes consumed more goods such as cars

• This deepened resource use and environmental damage

Population growth, urbanization, and industrialization worked together to transform the environment on a massive scale.

3. Resource Depletion and Scarcity

Resource Depletion

• Since the mid-1800s, humans have used about half of Earth’s petroleum resources

• Some experts predicted the remaining half could be consumed much faster

• Coal supplies might last longer, but dependence on coal would also risk future depletion

Water Scarcity

• The United Nations reported that 31 countries faced water scarcity

• More than 1 billion people lacked clean, accessible drinking water

• The World Health Organization predicted that by 2025, half of the world’s population would lack clean and safe drinking water

Inequality and Water Access

• Water scarcity affected people unequally

• In many developing countries, women and children bore the main burden of water collection

• This reduced time for:

  • paid work

  • schooling

• In Ghana, a 15-minute reduction in water collection time increased girls’ school attendance by 8% to 12%

4. Changes in the Atmosphere

Greenhouse Gases

• Factories, automobiles, airplanes, and industrial processes emitted large quantities of pollutants

• Important pollutants included carbon dioxide and other Greenhouse Gases

• These gases trap heat in Earth’s atmosphere, contributing to warming

Weakening Natural Carbon Sinks

• At the same time, forests and ground cover were shrinking

• This reduced Earth’s natural ability to absorb and store carbon

Global Warming

• Scientists linked fossil fuel use to rising average global temperatures

• Possible consequences included:

  • stronger hurricanes

  • more severe droughts

  • rising sea levels

  • flooding of islands and coastal areas

Carbon Footprint

• A Carbon Footprint is the amount of carbon dioxide a person produces

• Governments and activists argued that reducing carbon footprints was necessary to avoid catastrophe

5. Renewable Energy and Environmental Awareness

Renewable Energy

• Concern over fossil fuel dependence led governments and companies to invest in:

  • wind power

  • solar power

  • tidal power(潮汐能)

  • geothermal power(地热能)

• These sources were attractive because they are continuously replenished

• At first, development was slow because of high costs

• Later, improved technology made them more practical

• A 2018 study predicted that by 2050, half of the world’s electricity would come from wind and solar power

Early Environmental Awareness

Club of Rome

• Formed in 1968 in Europe

• Included scientists, diplomats, and industrialists

• Warned that resource depletion could limit economic growth

Green Party

• In many countries, people joined the Green Party

• The party focused on environmental issues in politics

Green Belt Movement

• Supported protection of wilderness from urban expansion

• By the 21st century, it had planted more than 51 million trees in Kenya

• Trees helped:

  • preserve ecosystems

  • reduce greenhouse gas effects

  • improve soil quality

  • create employment

6. Debates About Global Warming

Scientific Position

• Scientists, including those associated with the UN’s climate research efforts, argued that fossil fuel emissions were causing Global Warming

• Many activists began using stronger terms such as:

  • climate emergency(气候紧急状态)

  • climate crisis(气候危机)

Skeptics and Resistance

• Some climate-change skeptics questioned:

  • whether warming was happening

  • whether humans were responsible

• Some people in the energy industry resisted government intervention

• Others in the industry began preparing for a shift toward renewable fuels

Developed vs. Developing Countries

A major debate centered on who should reduce emissions first:

• Developed countries argued that developing countries needed to curb rapidly rising emissions

• Developing countries argued:

  • they were still trying to industrialize and reduce poverty

  • developed countries had already become rich through heavy fossil fuel use

• Another issue:

  • developing countries often produced less carbon dioxide per person

  • developed countries were expected by many to take the lead

Climate politics revealed a major tension between economic development and environmental responsibility.

7. International Agreements

Kyoto Protocol

• Signed in 1997

• First major international agreement to reduce carbon emissions

• Western European countries and the United States argued that countries such as China, India, Russia, and Brazil should reduce rising emissions

• However:

  • the United States refused to ratify it

  • China and India were not held to the strictest terms

Paris Agreement

• In 2015, 195 countries signed the Paris Agreement

• It created renewed hope for coordinated action against Global Warming

• Both the United States and China initially supported the deal

• In 2017, President Donald Trump announced that the United States would withdraw

8. Climate Activism

Greta Thunberg

• In 2018, teenage activist Greta Thunberg drew global attention to climate change

• Beginning with a solo protest in Sweden, she helped inspire a global climate strike

• More than 1.6 million people in over 125 countries participated

Extinction Rebellion

• Formed in 2018

• Used civil disobedience(公民抗命) in London

• Protesters:

  • blocked bridges and intersections

  • chained themselves to company headquarters

  • disrupted “business as usual”

• The movement pressured lawmakers to discuss responses to the climate crisis

Broader Impact

• Citizen groups across many countries pressured governments to prevent the worst consequences of continued warming

Environmental activism in the 21st century became increasingly global, youth-led, and confrontational.

9. A New Age? — Anthropocene

From Holocene to Anthropocene

• Traditionally, geologists called the current epoch the Holocene

• Some scientists argued that humans had changed the planet so deeply that a new term was needed: Anthropocene

Meaning of Anthropocene

• The term suggests that humans are now the dominant influence on Earth’s climate and environment

• In 2019, a panel of scientists voted to approve the name

Anthropocene reflects the idea that humanity has become a planetary force — for better and for worse.

10. Cause and Effect

Causes

• population growth

• urbanization

• globalization

• industrialization

• fossil fuel dependence

• rising consumer demand

Effects

• Deforestation and Desertification

• worse Air Quality

• Water Scarcity

• depletion of natural resources

• more greenhouse gas emissions

• Global Warming

• international agreements and activism

• development of Renewable Energy

Continuity

• Environmental harm continued despite scientific warnings

• Access to resources remained unequal

• Countries still disagreed over who should bear the cost of reform

Exam-ready Phrases and Sentences

• Increase pressure on natural resources

• Contribute to environmental degradation(导致环境恶化)

• Intensify competition for scarce resources

• Expand industrial pollution

• Reduce carbon emissions

• Shift toward renewable energy

• Debate responsibility for climate change

• Promote international environmental cooperation

• Respond to global warming through activism

• Highlight inequality in access to resources

• Population growth and industrialization contributed to deforestation, pollution, and water scarcity.

• Global Warming emerged as a major global issue because of greenhouse gas emissions from fossil fuels.

• International agreements such as the Kyoto Protocol and the Paris Agreement attempted to coordinate responses to climate change.

• Environmental activism grew as people demanded action to prevent further ecological damage.

• The concept of the Anthropocene reflected the growing human impact on Earth’s climate and environment.

LEQ / DBQ 使用思路

可用论点（Thesis Ideas）

• Since 1900, population growth, urbanization, and industrialization caused major environmental changes such as deforestation, water scarcity, and global warming, which in turn led to international debate and activism.

• While industrial and economic growth improved production and living standards in many regions, it also intensified resource depletion and environmental damage on a global scale.

• The modern era saw growing awareness of environmental crisis and greater international cooperation, but disagreements over responsibility and inequality limited effective action.

可写的分析方向

• Causation：人口增长、城市化、工业化如何共同推动环境变化

• Continuity and Change：环境破坏形式扩大了，但资源竞争和不平等依旧持续

• Comparison：发达国家与发展中国家在减排责任上的不同立场

• Global Context：环保问题为什么从国内议题变成国际议题

相关笔记

APWH Unit 9.4