C.1.1 Global Distribution of Extreme Environments Notes

Identifying Extreme Environments Based on Geography

1. Imagine standing in the blistering heat of the Sahara Desert or the icy winds of Antarctica.
2. These extreme environments are some of the most challenging places on Earth, yet they hold valuable insights into our planet's diversity.

What Makes an Environment "Extreme"?

1. Extreme environments are characterized by conditions that make survival difficult for most life forms.

These include:

1. Temperature Extremes: Intense heat or cold.
2. Limited Resources: Scarcity of water, nutrients, or arable land.
3. Isolation: Remoteness from human settlements or infrastructure.

Cold and High-Altitude Environments

1. Polar Regions: The Arctic and Antarctic

1. Location: Found at the Earth's poles.

Climate:

1. Freezing temperatures year-round.
2. Low precipitation, often classified as "cold deserts".

Key Features:

1. Ice Sheets and Glaciers: Cover vast areas, reflecting sunlight and regulating global climate.
2. Permafrost: Permanently frozen ground that supports unique ecosystems.

2. Glacial Areas: Mountainous Regions

1. Location: Found in high-altitude areas like the Himalayas, Alps, and Rockies.

Climate:

1. Cold temperatures with heavy snowfall.
2. Short summers with melting ice.

Key Features:

1. Glaciers: Rivers of ice that shape the landscape through erosion.
2. Thin Soils: Poor for agriculture due to erosion and freezing.

3. Periglacial Areas: Tundra and Beyond

1. Location: Found in regions with seasonal freezing and thawing, such as Siberia and Alaska.

Climate:

1. Cold winters and cool summers.
2. Low precipitation, often as snow.

Key Features:

1. Permafrost: Supports tundra vegetation like mosses and lichens.
2. Frost Action: Creates unique landforms like pingos (ice-cored hills).

4. High Mountains in Non-Polar Regions

1. Location: Andes, Rockies, and Tibetan Plateau.

Climate:

1. Cold temperatures due to altitude.
2. Variable precipitation, with some areas in rain shadows.

Key Features:

1. Steep Slopes: Difficult for construction and agriculture.
2. Thin Air: Low oxygen levels affect human and animal life.

Hot Arid Environments

1. Hot Deserts: The Sahara, Arabian Desert, Kalahari, and Parts of Australia

1. Location: Found near the Tropics of Cancer and Capricorn.

Climate:

1. High temperatures during the day, cold nights.
2. Less than 250 mm of rainfall annually.

Key Features:

1. Sand Dunes and Rocky Plateaus: Shaped by wind erosion.
2. Sparse Vegetation: Adapted to conserve water, like cacti and succulents.

Example

The Sahara Desert covers over 9 million square kilometers, making it the largest hot desert in the world.

2. Semi-Arid Areas: The Sahel, Southwest of the USA, Central Asia, and Parts of Australia

1. Location: Transitional zones between deserts and more humid regions.

Climate:

1. 250–500 mm of rainfall annually.
2. Seasonal variability, with wet and dry periods.

Key Features:

1. Grasslands and Shrubs: Support grazing but are vulnerable to overuse.
2. Flash Floods: Occur during rare but intense rainstorms.

Why Study Extreme Environments?

1. Climate Regulation: Polar ice sheets with high albedo reflect sunlight, helping to cool the planet.
2. Biodiversity: Unique species have adapted to survive in harsh conditions.
3. Human Adaptation: Indigenous communities offer insights into sustainable living.

Reflection and Broader Implications