1 Impact of Rapid Population Growth on the Environment
(1) Accelerates the consumption of natural resources
(2) Leads to serious environmental degradation
- Endangering human and other species' survival
2 What is Earth's Carrying Capacity?
The number of people that Earth's resources can sustain.
3 How to Reduce Human Impact on the Environment?
(1) Control population growth
(2) Change resource development patterns
(3) Control pollution
4 What Are Renewable Resources?
Resources that can be replenished through natural processes after being consumed.
Note: Whether a resource is renewable often depends on perspective.
For true renewability, the natural replenishment rate must exceed the consumption rate.
5 Examples of Renewable Resources
(1) Forests
(2) Fish
(3) Freshwater
(4) Certain minerals in soil
6 Why Is Freshwater a Renewable Resource?
After consumption, it is replenished through rainfall.
7 Which Minerals in Soil Are Renewable?
Nitrates are replenished through the nitrogen cycle after being absorbed by plants.
Note: Minerals like metals used by humans are all non-renewable.
8 Examples of Non-Renewable Resources
(1) Fossil fuels
(2) Metals
9 Examples of Fishing Methods That Severely Damage Marine Ecosystems
(1) Cyanide fishing
(2) Explosives (fish bombing)
(3) Bottom trawling
(4) Drift nets
10 Impacts of Unsustainable Fishing Practices
(1) Overfishing
(2) Destruction of marine habitats (e.g., coral reefs)
(3) Killing non-target species
(4) Disrupting ecological balance
11 Environmental Issues Caused by Unsustainable Agriculture
(1) Destruction of natural habitats (e.g., deforestation)
(2) Pollution (e.g., pesticides, chemical fertilizers, organic waste)
12 How Do Pesticides Affect the Ecosystem?
Some pesticides contain stable chemicals, often highly lipid-soluble.
These chemicals are difficult for organisms to degrade or excrete, leading to bioaccumulation.
When herbivores consume plants contaminated with pesticide residues, the stable chemicals accumulate in their bodies.
Higher trophic level consumers ingest these herbivores, transferring the chemicals up the food chain.
Since higher trophic organisms eat large quantities of lower trophic organisms, the chemicals accumulate further (biomagnification).
High concentrations of these chemicals can harm or even kill top-level consumers.
13 How Do Chemical Fertilizers Affect the Ecosystem?
Chemical fertilizers are inorganic salts and nutrients for algae.
When dissolved in water, fertilizers may leach into rivers, increasing nutrient levels (eutrophication).
This leads to excessive algal growth.
At night, algae consume oxygen during respiration, drastically reducing dissolved oxygen levels in water.
Some oxygen-dependent organisms may die due to oxygen depletion.
14 How Do Animal Wastes Affect the Ecosystem?
Animal wastes, such as feces and carcasses, contain large amounts of organic matter and bacteria.
They serve as a food source for aquatic bacteria, causing rapid bacterial growth.
When bacteria decompose organic matter, they consume oxygen in water.
This drastically reduces dissolved oxygen levels, potentially causing oxygen-dependent organisms to die.
15 Environmental Impacts of Urbanization and Industrialization
(1) Land reclamation
(2) Coastal reclamation
(3) Air pollution
(4) Water pollution
16 How Does Land Reclamation Affect the Environment?
(1) Habitat destruction
Threatens wildlife survival
Reduces biodiversity
(2) Habitat fragmentation
Caused by the construction of roads or railways
17 How Does Coastal Reclamation Affect the Environment?
(1) Destruction of coastal habitats
(2) Consequences of dredging:
- Destroys seabeds, disrupting marine habitats
- Kills organisms living on the seabed
- Suspended particles block sunlight, hindering photosynthesis in algae and plants
- Dredged sediment may contain toxic chemicals
18 Health Issues Caused by Air Pollution
(1) Respiratory diseases caused by inhalable suspended particles
(2) Photochemical smog causing respiratory diseases
(3) Carbon monoxide poisoning
(4) Lead particle poisoning
19 What Are Some Global Environmental Issues?
(1) Global warming
(2) Acid rain
(3) Excessive algal growth
20 What Is the Greenhouse Effect?
Certain gases in the atmosphere, such as water vapor, carbon dioxide, nitrogen oxides, and methane, absorb some infrared radiation released by Earth's surface, warming the atmosphere.
21 Causes of Global Warming (Human Factors)
(1) Burning forests, releasing large amounts of carbon dioxide
(2) Deforestation, reducing photosynthesis rates and slowing the removal of carbon dioxide from the atmosphere
(3) Burning fossil fuels
(4) Raising livestock like cows and sheep, which produce methane during digestion
(5) Human-induced wildfires
22 Impacts of Global Warming
(1) Melting polar ice caps, causing polar species to lose habitats or food
(2) Abnormal weather patterns
(3) Migration of species, potentially leading to extinction of some
(4) Death of temperature-sensitive species (e.g., coral)
(5) Spread of tropical diseases in warmer regions
23 What Is Acid Rain?
Rain with a pH below 5.6.
Note: Normal rain is also slightly acidic.
24 Causes of Acid Rain
Emissions from burning fossil fuels contain sulfur dioxide and nitrogen oxides.
25 Impacts of Acid Rain
(1) Kills acid-sensitive aquatic organisms
(2) Causes some fish to lose weight
(3) Damages leaves, leading to tree death
(4) Releases aluminum ions from soil, which are toxic to plant roots
(5) Dissolves nutrients in soil, leading to soil infertility
26 Causes of Excessive Algal Growth
Discharge of large amounts of inorganic salts into water.
27 Impacts of Excessive Algal Growth
(1) At night, algae consume oxygen during respiration, depleting oxygen in water.
(2) Algae covering the water surface block sunlight, preventing aquatic plants underneath from photosynthesizing and causing their death.
(3) Bacteria decompose dead algae, further depleting oxygen in water and possibly releasing toxic substances.
(4) Some algae release toxins (e.g., ciguatoxins), which can accumulate in organisms.