Geography | Fragile environments and climate change

Welcome to Topic 7: Fragile Environments and Climate Change!

Hi Geographers! This chapter is one of the most important and relevant topics you will study. It sits in the "Global Issues" section because it deals with threats that affect every single person on Earth.
We will look at parts of the world that are easily damaged (fragile environments), why they are being destroyed, and how we can manage these global problems like desertification, deforestation, and climate change.
Don't worry if these sound like huge problems—we'll break down the causes and solutions into simple, manageable steps. Let's get started!

Section 1: What Makes an Environment Fragile? (7.1a)

Defining and Locating Fragile Environments

A fragile environment is an ecosystem that is easily disturbed or damaged and struggles to recover when human activities or natural changes occur.
These places often have slow-growing vegetation or poor soils, making them highly vulnerable.

The syllabus requires you to understand the distribution and characteristics of these environments. Think about where the climate is extreme or the nutrients are scarce:

• Rainforests: While they look strong, their environment is fragile because almost all the nutrients are held in the vegetation itself, not the shallow soil. If you cut the trees, the soil quickly becomes useless.
• Tundra and Arctic regions: The permafrost (permanently frozen ground) is easily damaged by building or drilling. The food webs here are very simple, so disrupting one species can destroy the whole ecosystem.
• Drylands (Deserts and Semi-Arid Areas): The small amount of vegetation struggles to grow back once it's removed by grazing animals or drought.

Section 2: The Major Threats Facing Fragile Environments (7.1b & 7.1c)

2.1 Threat 1: Desertification (7.1b)

Desertification is the process where fertile land turns into desert, typically on the edges of existing deserts (semi-arid areas). This is not caused by the desert physically moving, but by the land degrading.

Causes of Desertification

These causes are often a combination of natural factors and human pressure:

• Drought: This is a natural factor. Long periods of below-average rainfall kill off vegetation, leaving the soil exposed.
• Population Pressure: As populations grow, more land is needed for farming, leading to over-cultivation (using the same land too often). This depletes soil nutrients.
• Overgrazing: Too many animals (cows, goats) eat the vegetation faster than it can regrow, removing the protective layer of grass and exposing the soil to wind erosion.
• Fuel Supply: People in poverty rely on wood for fuel. Cutting down trees (deforestation) removes the tree roots that bind the soil together.
• Migration: People forced out of degraded areas move into other semi-arid regions, putting increased strain on those new lands.

2.2 Threat 2: Deforestation (7.1b)

Deforestation is the large-scale removal of forests. This is often focused on tropical rainforests, which are huge stores of carbon and biodiversity.

Key Human Causes of Deforestation

• Commercial Timber Extraction: Logging companies cut down trees for valuable wood (e.g., mahogany) to sell globally.
• Agriculture (Farming): This is usually the biggest driver. Forests are cleared for:
  • Cattle ranching (huge areas needed for grazing).
  • Plantations (growing single crops like palm oil or soya beans).
• Mining: Clearing large areas to extract resources like gold, iron ore, or bauxite. This requires roads and infrastructure, causing further damage.
• Transport: Building roads (like the Trans-Amazonian Highway) opens up previously inaccessible areas to loggers and settlers.
• Settlement and HEP: Forests are cleared for new towns, farms, and to build large dams for Hydroelectric Power (HEP), which floods vast tracts of forest.

2.3 Threat 3: Global Climate Change (7.1c)

Climate change refers to long-term shifts in temperatures and weather patterns. These changes can be natural, but currently, they are massively accelerated by human actions.

Causes of Natural Climate Change

It is important to know that Earth's climate has always changed naturally due to physical processes:

• Milankovitch Cycles: These are long-term changes in the Earth’s orbit, axial tilt, and wobble. They change how much solar energy the Earth receives. (Think of the Earth as a spinning top that sometimes tilts differently or follows an oval path around the sun.)
• Solar Variation: Changes in the sun’s energy output, often linked to sunspots (dark areas on the sun's surface).
• Volcanism (Volcanic Activity): Large eruptions release ash and dust into the atmosphere, which can block sunlight and cause short-term global cooling.

Causes of the Enhanced Greenhouse Effect (Human Activities)

The Greenhouse Effect is natural and keeps the Earth warm enough for life. However, human activity has increased the concentration of greenhouse gases (like CO2, Methane) in the atmosphere, making it enhanced.

• Industry and Energy Production: Burning fossil fuels (coal, oil, gas) in power stations and factories releases huge amounts of Carbon Dioxide (\(CO_2\)).
• Transport: Cars, planes, and ships mostly run on fossil fuels, releasing \(CO_2\).
• Farming (Agriculture):
  • Cattle produce methane when they digest food (a powerful greenhouse gas).
  • Rice paddies also release methane.
  • The use of artificial fertilisers releases nitrous oxide.

Section 3: The Serious Impacts of Environmental Change (7.2)

3.1 Impacts of Desertification and Deforestation (7.2a & 7.2b)

These two processes directly damage the land, leading to similar devastating consequences for people and the environment.

Social and Economic Impacts (7.2a & 7.2b)

• Reduced Agricultural Output: Soil erosion means less fertile land, leading to smaller crop yields and lower farm incomes.
• Malnutrition and Famine: When crops fail due to poor soil (desertification) or droughts (climate change), food supplies drop drastically, causing hunger and death.
• Migration: People become environmental refugees, forced to leave their homes in search of food and water, often moving to urban centres or different countries.
• Economic Development: Deforestation can initially boost a country’s GDP through timber or mining exports, but in the long term, it creates economic instability as natural resources are depleted.

Environmental Impacts (7.2b)

• Loss of Biodiversity: Rainforests contain half the world's species. When the forest is cut down, habitats are destroyed, leading to species extinction.
• Increased Soil Erosion: Tree roots hold the soil together. Without them, rain washes away the topsoil rapidly, making the land unusable and increasing the risk of landslides.
• Contribution to Climate Change: Deforestation releases stored carbon into the atmosphere when trees are burned or decompose, accelerating the enhanced greenhouse effect.

3.2 Negative Effects of Global Climate Change (7.2c)

Climate change has widespread negative effects globally, particularly on fragile environments and the people who live near them.

Key Climate Change Impacts

• Rising Sea Levels: Caused by melting glaciers and ice sheets, and the thermal expansion of seawater (warmer water takes up more space). This threatens low-lying coastal areas and islands, forcing settlement patterns to change.
• More Hazards: Climate change increases the frequency and intensity of extreme weather events, such as heatwaves, severe droughts, and powerful tropical storms.
• Ecosystem Changes: Rising ocean temperatures cause coral bleaching (killing coral reefs). Changes in rainfall and temperature force species to migrate or die out.
• Health and Wellbeing Challenges: Warmer temperatures can expand the range of diseases (like malaria) carried by insects. Heatwaves cause severe illness and death.
• Food Supply: Changing climate patterns disrupt predictable growing seasons, leading to crop failure and reduced food security, especially in tropical regions.
• Reduced Employment Opportunities: Industries dependent on stable environments, such as agriculture, fisheries, and winter tourism, suffer losses, leading to unemployment.

Section 4: Managing the Challenges – Responses (7.3)

4.1 Responses to Desertification (7.3a)

Managing desertification requires tackling the lack of water and restoring soil health.

The Role of Technology

Technology can help resolve water-resource shortages, making fragile drylands more productive and resilient:

• Drip Irrigation: This technology delivers small amounts of water directly to the plant roots, minimizing water waste through evaporation (which is a huge problem in hot, dry areas).
• Water Harvesting: Building small bunds (earthen walls) or trenches to capture rainfall and slow runoff, allowing the water to soak into the ground.
• Drought-resistant crops: Using genetically modified or naturally resilient crops that require less water (e.g., millet or sorghum instead of maize).
• Solar Pumps: Using solar energy to power pumps to extract deep groundwater sustainably.

4.2 Approaches to Sustainable Deforestation Management (7.3b)

The goal is to use the rainforest's resources without destroying them permanently. This is called sustainable use and management.

The syllabus requires you to refer to a named rainforest region. (Make sure you have a detailed case study for this, e.g., the Amazon or Malaysia.)

Different Approaches to Limit Deforestation

• Selective Logging: Only cutting down mature, desired trees, and leaving the rest of the ecosystem intact. This allows the forest to regenerate naturally.
• Ecotourism: Developing small-scale, environmentally friendly tourism that generates income for local people, providing an economic alternative to logging or ranching.
• Education and Monitoring: Using satellite technology (remote sensing) to track illegal logging and educating local communities on the value of the forest.
• Creation of National Parks/Reserves: Protecting vast areas legally so development is banned or severely restricted.

4.3 Responses to Global Warming and Climate Change (7.3c)

Responses to climate change can be split into three groups: Governments, Organisations, and Individuals. We must also consider how these responses differ between developed (HICs) and emerging/developing countries (LICs/NEEs).

Responses from Governments and International Organisations

• International Agreements: Global agreements like the Paris Agreement aim to limit global temperature rise to below 2°C (and ideally 1.5°C). Governments agree to set national emission reduction targets.
• Carbon Taxes and Permits: Governments impose taxes on companies that produce large amounts of carbon, or issue permits (allowing a set amount of pollution), encouraging them to switch to cleaner energy.
• Investment in Renewable Energy: Providing funding and subsidies for solar, wind, and geothermal power to reduce reliance on fossil fuels.

How Responses Vary by Development Level

The ability and willingness to respond to climate change differ greatly:

Developed Countries (HICs) - Example: UK or USA

• Focus: Primarily on mitigation (reducing the causes) and adaptation (adjusting to impacts).
• Strategy: Heavy investment in expensive renewable infrastructure (offshore wind farms), strict emission laws, and funding research into Carbon Capture and Storage (CCS).
• Challenge: High historical emissions; public may resist lifestyle changes (e.g., high fuel taxes).

Emerging or Developing Countries (LICs/NEEs) - Example: China, India, Bangladesh

• Focus: Primarily on adaptation, as they are often more physically vulnerable to the impacts (sea-level rise, drought). They also focus on economic development.
• Strategy: Building coastal defences (like sea walls in Bangladesh), developing drought-resistant crops, and seeking financial aid from richer nations to transition to green energy (e.g., China's massive solar panel production).
• Challenge: Lack of funds and technology; massive population growth means energy demand is high, often requiring cheap, carbon-intensive energy (like coal) for rapid economic growth.