CCST9013 Lecture Notes: Introduction to Our Living Environment

**Lecture 1 - Introduction to Our Living Environment** **Introduction** - **Key Topics**: - How the environment affects us. - How we affect the environment. - How to address environmental problems. **How the Environment Affects Us** **Example 1: Global Temperature Changes*...

**Lecture 1 - Introduction to Our Living Environment** **Introduction** - **Key Topics**: - How the environment affects us. - How we affect the environment. - How to address environmental problems. **How the Environment Affects Us** **Example 1: Global Temperature Changes** - Over the past 500 million years, Earth\'s average surface temperature has fluctuated significantly: - Most of Earth\'s history has been too warm for persistent polar ice caps. - The past 50 million years are an exception. - **The Younger Dryas**: - A near-glacial period known for abrupt temperature changes. - Named after a cold-climate flower: *Dryas octopetala*. - Likely influenced the development of agriculture. - **Natufian Culture**: - Existed in the Levant \~12,000 years ago. - Transitioned from hunting-gathering to early farming in the Fertile Crescent. - Domesticated crops (peas, lentils, barley) and animals (goats, oxen). - Evidence of dog domestication (e.g., burial site in Israel). **Example 2: Earthquakes** - **Historical Earthquakes**: - Earthquakes (magnitude 6.0+) from 1900--2017. - Magnitude 8.0+ quakes from 1900--2018. - **Haiti Earthquakes**: - 2010: Magnitude 7.0 caused severe destruction, exacerbated by Haiti\'s geology (sits on fault lines between the North American and Caribbean plates). - 2021: Magnitude 7.2 affected \~1.2 million people, including 540,000 children. - **Impact**: - Haiti\'s unique geology increases seismic vulnerability. - Children suffer most due to limited access to shelter, water, and healthcare. **Example 3: Radon** - **Radon**: - A radioactive, odorless, colorless gas. - Second leading cause of lung cancer in the U.S., causing 15,000--22,000 deaths annually. **How We Affect the Environment** **Example 1: BP Oil Spill (Deepwater Horizon)** - **Details**: - Largest U.S. oil spill (87 days, 200 million gallons of crude oil). - Affected 26,000 km of coastline (Texas, Louisiana, Mississippi, Alabama, Florida). - **Environmental Impacts**: - Immediate: Dead or injured animals (birds, turtles, coral). - Long-term: Dolphins still exhibit health issues 10 years later. - **Offshore Drilling**: - Involves high environmental risks. - Debate over environmental damage vs. economic benefits. - **Deepwater Drilling**: - High-risk activity in depths \>1,000 meters. **Example 2: Human Population Growth** - **Global Issues**: - Rapid growth exacerbates environmental problems. - Leads to urbanization, resource depletion, and pollution. **Example 3: Climate Change** - **IPCC (Intergovernmental Panel on Climate Change)**: - Key Findings: - Global surface temperature has increased by 1.09°C (2011--2020 vs. 1850--1900). - Sea level rise has nearly tripled since 1901--1971. - Human activity is the main driver of glacier retreat and Arctic sea-ice loss. - Extreme weather events (heatwaves, floods) have intensified since the 1950s. - Consequences: - Current warming is \~1°C above pre-industrial levels. - Likely to surpass 1.5°C between 2030--2052. - **Why 1.5°C Matters**: - Vulnerable countries (e.g., island nations) face existential threats. - Paris Agreement aims to limit warming below 2°C, with efforts to stay below 1.5°C. **Solutions:** - **Example**: - Philippine schools made from recycled bottles. **Lecture 2 - Earth Facts** **Fact 1: The Earth is the 3rd Planet from the Sun** - **What Makes a Planet**: 1. Orbits a star (Sun). 2. Big enough for gravity to form a spherical shape. 3. Cleared other objects in its orbital path. - **Habitable Zone**: 4. Range where liquid water can exist on a planet's surface. **Fact 2: Earth\'s Layers** - **Three Layers**: - Crust, mantle, core. - **Studying Earth\'s Interior**: - **Seismic Waves**: Vibrations caused by earthquakes or explosions. - Travel speed depends on material type. - **Peridotite**: Dominant rock in the mantle. **Fact 3: Tectonic Plates Move** - **Theory of Plate Tectonics**: - Earth\'s lithosphere (crust + upper mantle) moves due to mantle heat. - **Movement Types**: 1. **Convergent**: Plates collide (e.g., Himalayas). 2. **Divergent**: Plates move apart, creating new landmasses (e.g., East Africa Rift). 3. **Transform**: Plates slide past each other, causing earthquakes. **Fact 4: Extinctions Happen** - **Species Extinction**: - 99.9% of all species are extinct. - Average lifespan: 10 million years. - **Dodo Example**: - Extinct due to habitat destruction and invasive species. - **Dinosaur Extinction**: - Likely caused by the Chicxulub asteroid impact (\~65 million years ago). **Lecture 3 - Natural Resources** **Water** - 71% of Earth\'s surface is covered by water. - **Water Stress**: - Population growth, urbanization, and climate change exacerbate water scarcity. - **Groundwater Depletion**: - Over-pumping causes land subsidence, contamination, and reduced food production. **Non-Renewable Resources** - **Gold Mining**: - Environmental Impacts: - Pollution (air, water, soil). - Acid mine drainage harms ecosystems. **Renewable Energy** - **Examples**: - Solar, wind, geothermal, hydro. - **Pros/Cons**: - Clean but weather-dependent (e.g., no sun/wind = no energy). - **Geothermal Energy**: - Found near volcanoes, hot springs, geysers. **Lecture 4 - Our Ocean** **Ocean Basics** - 71% of Earth\'s surface is covered by oceans. - **Key Functions**: - Stabilizes climate. - Supports ecosystems and livelihoods. - Source of food, energy, and water. **Ocean Sediments** - **Types**: 1. **Terrestrial**: From land (e.g., rivers, glaciers). 2. **Biogenic**: From organisms (e.g., shells, skeletons). 3. **Volcanic**: From eruptions. 4. **Wind-Blown Dust**: From deserts. **Marine Life Zones** - Divided by depth and light availability. **Human Impact** - **Plastic Pollution**: - Major issue affecting marine ecosystems. **Lecture 5: Stephen Hui Geological Museum** **1. Museum Overview** - Hong Kong\'s sole geological museum, established on **January 16, 2009**. - Provides Earth Science education and promotes stewardship of the Earth. - Features fossils, minerals, and rocks, offering educational opportunities for students and the general public. **2. Key Exhibits** **Dynamic Earth** - Highlights the geological forces that shape and transform Earth\'s landscapes. **Earth Evolution** - Fossils showcase **4.5 billion years** of Earth\'s history and evolution. **Earth Materials** - Displays the formation of minerals and rocks and their significance in daily life. **Hong Kong Geo-history** - Rocks and fossils reveal Hong Kong\'s transition from sedimentary basins to its modern landscape. **3. Early Life in the Ocean** - **Life in the Ocean**: - Emerged **4 billion years ago** with single-celled organisms like cyanobacteria (**3.5 billion years ago**). - Early life forms include arthropods, molluscs, corals, and jellyfish. - **Cambrian Explosion**: - First appearance of hard shells and skeletons. - Famous fossil locations: - **Burgess Shale (Canada)**. - **Chengjiang Biota (China)**. **Key Cambrian Organisms** 1. **Anomalocaris**: - First predator, up to **2m** long. - Equipped with flexible stalked eyes and sharp teeth. 2. **Trilobite**: - Developed hard shells and spines for protection and digging. 3. **Maotianshania**: - Mud-dwelling deposit feeder. **4. Minerals in Daily Life** - **Sustainable Use of Minerals**: - Humans extract **60 billion tons** of raw materials yearly. - Recycling is necessary for sustainability. **Uses of Metallic Minerals** 1. **Aluminum**: - Used in windows, cans. 2. **Copper**: - Found in wiring, cookware, coins. 3. **Magnetite**: - Used in water filters, concrete. **Uses of Non-metallic Minerals** 1. **Silicon**: - Found in glass, solar cells, computer chips. 2. **Graphite**: - Found in batteries, pencils, lubricants. **5. Rocks and the Rock Cycle** - **Rock Types**: Igneous, sedimentary, metamorphic. - **Rock Cycle**: - Rocks are continuously formed, broken down, and reformed through processes like melting, cooling, and weathering. **Lecture 6: Natural Hazards** **1. Earthquake** - Caused by the sudden release of stress in Earth\'s crust. - **Epicenter**: Point on the surface directly above the hypocenter. - **Richter Scale**: Measures the energy released by earthquakes. - Around **1,500 earthquakes** of magnitude 5 or higher occur yearly. **Types of Plate Movements:** 1. **Convergent**: Plates move towards each other, forming mountains or volcanoes. 2. **Transform**: Plates slide past each other, releasing energy (e.g., San Andreas Fault). **Mitigation:** - Earthquakes cannot be prevented but damages can be reduced through: - Building regulations. - Public awareness campaigns. **2. Tsunami** - Series of ocean waves caused by underwater disturbances. - Waves can travel at **805 km/h**. - **Examples**: - **2004 Indian Ocean Tsunami**: Energy equivalent to **23,000 atomic bombs**. - **2011 Tohoku Tsunami**: Waves up to **40m**, caused Fukushima nuclear disaster. **3. Volcanic Eruption** - A volcano is an opening on Earth's surface for magma, gases, and ash to escape. - **Volcanic Explosivity Index (VEI)**: Measures eruption explosiveness. - **Example**: - **2022 Tonga Eruption**: Largest atmospheric explosion in over 100 years. **4. Typhoon** - Formed over warm ocean waters near the equator. - **Storm Surge**: High winds push seawater onto land, causing flooding. - **Example**: - **Typhoon Haiyan**: Winds reached **300 km/h**, one of the strongest typhoons recorded. **Lecture 7: Human Population and Impacts** **1. Human Evolution** - Common ancestor of humans and chimpanzees lived around **7 million years ago**. - **Early Human Traits**: - Opposable thumbs, large cerebrum, omnivorous diet. **2. Key Milestones in Human Evolution** - **Tools and Fire**: Enabled environmental control and brain development. - **Benefits of Meat**: - High-calorie, protein-rich diet enabled brain growth and energy efficiency. **3. Major Human Species** 1. **Australopithecus**: - Lived **2-4 million years ago**, walked upright. 2. **Homo habilis**: - Appeared **1.5 million years ago**, used stone tools. 3. **Homo erectus**: - Developed complex tools, controlled fire. 4. **Homo neanderthalensis**: - Skilled hunters and toolmakers. 5. **Homo sapiens**: - Modern humans appeared **200,000 years ago**. **4. Evolution of the Brain** - **Advantages**: - Stores information, solves problems. - **Costs**: - Brain consumes **20%** of the body's energy. **Lecture 8: Global Warming** **1. Impacts of Global Warming** - Rising temperatures lead to sea level rise and frequent extreme weather events. - Greenhouse gases (e.g., CO2) are the primary cause. **2. Mitigation Measures** - Reduce fossil fuel use. - Develop renewable energy (e.g., solar, wind). - Promote public education and policy support.