3.2.2 Climate Change and the Nexus Notes

Climate Change as a Destabilizer of Resource Systems

1. Climate change - long-term shifts in temperatures and weather patterns, primarily driven by human activities such as burning fossil fuels which disrupts the balance of critical resource systems:
   1. Hydrosphere: water systems
   2. Biosphere: ecosystems and agriculture
   3. Energy systems: production and consumption

Hydrosphere: Melting Glaciers and Altered Rainfall Patterns

Melting Glaciers

1. Glaciers act as natural reservoirs, storing water in winter and releasing it in summer.
2. As glaciers melt faster than they can replenish, regions dependent on glacial meltwater face:
   1. Short-term flooding: Rapid melting increases river flow.
   2. Long-term water scarcity: Once glaciers shrink, less water is available.

Example

The Hindu Kush Himalayan (HKH) region, often called the "Third Pole" supplies water to nearly 2 billion people in Asia through major rivers like Indus, Ganges, Brahmaputra, Mekong, Yangtze, and Yellow River. As HKH glaciers melt, countries like India, Pakistan, Vietnam and China face increased water stress.

Altered Rainfall Patterns

1. Climate change disrupts traditional rainfall cycles, leading to:
   1. Droughts: Prolonged dry periods reduce water availability.
   2. Floods: Intense rainfall overwhelms infrastructure and contaminates water supplies.

Biosphere: Crop Failures and Habitat Loss

Crop Failures

1. Rising temperatures and extreme weather events directly impact agriculture:
   1. Heatwaves: Reduce crop yields by stressing plants.
   2. Droughts: Limit water for irrigation, leading to lower productivity.
   3. Pests and Diseases: Warmer climates expand the range of harmful organisms.

Habitat Loss

1. Climate change alters ecosystems, threatening biodiversity:
   1. Species Migration: Animals and plants move to cooler areas, disrupting ecosystems.
   2. Coral Bleaching: Warmer oceans cause coral reefs to die, affecting marine life and coastal communities.