D4.2.3 Deforestation of Amazon rainforest Notes

The Amazon Acts as Earth’s Natural Humidifier

1. The Amazon rainforest regulates the Earth’s climate by producing oxygen, storing carbon, and recycling rainfall through transpiration.

Transpiration Recycles Rainfall and Cools the Air

1. Transpiration allows plants to release water vapor, which cools the air, forms clouds, and recycles rainfall:
   1. Cooling Effect: Water evaporation cools the surrounding air.
   2. Cloud Formation: Rising water vapor condenses into clouds, leading to rain.
   3. Rainfall Recycling: Up to 50% of the Amazon’s rainfall is recycled through transpiration, sustaining biodiversity.

Deforestation Risks Pushing the Amazon Past a Tipping Point

1. The reduction in transpiration caused by deforestation creates a positive feedback loop:
   1. Less Transpiration: Fewer trees release less water vapor, reducing rainfall.
   2. Drier Conditions: Increased fire risk further reduces forest cover.
   3. Self-Reinforcing Cycle: Fewer trees lead to even less rainfall, accelerating forest loss.

Losing 20-25% of the Forest Could Trigger Irreversible Change

1. Scientists estimate that losing 20-25% of the Amazon could transform it into a savanna-like grassland, with dramatic consequences for biodiversity and the climate.

Deforestation Accelerates Climate Change and Biodiversity Loss

Amazon Deforestation Releases Massive Carbon Stores

1. The Amazon stores approximately 120 billion tonnes of carbon.
2. This is released as carbon dioxide when trees are cut or burned, contributing to global warming.

Biodiversity Collapses Without Amazon Ecosystems

1. The Amazon harbors 10% of all known species.
2. Deforestation destroys habitats and disrupts interactions between species, pushing ecosystems toward collapse.

Deforestation Threatens Indigenous Communities

1. Local and Indigenous communities rely on the Amazon for food, medicine, and cultural traditions.
2. Deforestation undermines their livelihoods and erodes centuries-old practices.

Percentage Changes Quantify Forest Loss Over Time

Deforestation can be measured using percentage change:

Formula:

$$
\text{Percentage Change} = \frac{\text{Final Amount} - \text{Initial Amount}}{\text{Initial Amount}} \times 100
$$

The Amazon’s Stability Requires Global Protection Efforts

1. The Amazon is essential for stabilizing the climate, preserving biodiversity, and supporting local communities.
2. Protecting it is a global priority to prevent tipping points that could lead to irreversible damage.