Lecture Notes: Homo Sapiens and Earth's Story

Introduction

• Humans, known as Homo sapiens, appeared 200,000 years ago.
• Life began around 4 billion years ago.
• Humans have disrupted the balance essential for life.

Origin of Earth

• Earth was initially a chaotic cloud of fire, similar to others in the universe.
• Life has been a link in the living chain for more than 4 billion years.
• New volcanoes provide insights into early Earth: molten rock and dense atmosphere.

Evolution of Life

• Primitive life forms like archaeobacteria existed in hot springs.
• Cyanobacteria could capture solar energy, ancestors of plants.
• Life altered Earth's atmosphere, removing carbon dioxide.

Earth's Water Cycle

• Water is continually renewed: oceans, glaciers, rivers, etc.
• Water takes various forms between liquid, gas, and solid.

Earth's Balance and Biodiversity

• Everything is interconnected: water, air, life.
• Green stretches (algae) produce 70% of Earth's oxygen.
• Coral reefs and trees play vital roles in ecological balance.

Human Development

• After 180,000 years, humans settled due to favorable climate.
• Agriculture revolutionized human history, leading to cities and civilizations.

Energy and Industrialization

• Discovery of coal, oil, and gas freed humans from agricultural labor.
• Industrialization led to rapid urbanization and environmental change.

Environmental Impact

• Industrial farming became oil-dependent, standardizing food production.
• Mining and resource extraction increased drastically.
• Globalization boosted trade and environmental pressure.

Climate Change and Pollution

• Carbon emissions disrupt Earth's climate balance.
• Global warming effects are most visible at the poles.
• Sea levels rise, threatening low-lying land.

Social and Economic Inequality

• The gap between rich and poor is widening.
• Many live in resource-rich yet impoverished areas.

Environmental Preservation Efforts

• Success stories in education, reforestation, and sustainable practices.
• Renewable energy sources like solar, wind, and geothermal are growing.

Conclusion

• Solutions for environmental issues exist today.
• Humans must act together to change and preserve Earth's resources.