Rainforest degradation and its Impact
14th Mar, 2022
More than 75 per cent of the Amazon rainforest has been likely heading towards a tipping point since the early 2000s.
- It may be losing its ability to bounce back from extreme events such as drought or fire, threatening to become a dry savanna-like ecosystem. The researchers used satellite data and statistical tools to arrive at these findings.
What are Rainforests?
- A rainforest is an area of tall, mostly evergreen trees and a high amount of rainfall.
- Rainforests are Earth’s oldest living ecosystems, with some surviving in their present form for at least 70 million years.
- They are incredibly diverse and complex, home to more than half of the world’s plant and animal species—even though they cover just 6% of Earth’s surface.
- These are large tropical rainforest occupying the drainage basin of the Amazon River and its tributaries in northern South America and covering an area of 6,000,000 square km.
- Tropical forests are closed-canopy forests growing within 28 degrees north or south of the equator.
- They are very wet places, receiving more than 200 cm rainfall per year, either seasonally or throughout the year.
- Temperatures are uniformly high - between 20°C and 35°C.
- The Amazon’s rainforest is home to 30 per cent of the world’s species, comprising 40,000 plant species, 16,000 tree species, 1,300 birds and more than 430 species of mammals.
Rainforest as Climate stabilizer:
- Rainforests help stabilize the world’s climate by absorbing carbon dioxide from the atmosphere.
- Therefore, living rainforests have an important role in mitigating climate change.
- But when rainforests are chopped down and burned, the carbon stored in their wood and leaves is released into the atmosphere, contributing to climate change.
- Hence, a degraded forest transforms from Carbon Sink to Carbon Source.
Rainforests and rainfall:
- Rainforests contribute to rainfall through transpiration, which is the process of water movement through a plant and its release into the air via leaves, stems, and flowers.
- Plants release water as a byproduct of photosynthesis.
- Water released by plants contribute to local humidity or moisture in the air.
- Because a forest consists of a large number of trees, the volume of water released via transpiration can contribute to the formation of rain clouds, resulting in rainfall.
- Very large rainforests, like the Amazon, can drive rainfall over very large areas. By one estimate, the Amazon is responsible for 70% of rainfall in southern Brazil.
Rainforests and local temperature
- Tropical forests can have a localized cooling effect by increasing humidity through transpiration and contributing to wind currents.
- Additionally, shade from the forest canopy can result in dramatically cooler temperatures relative to areas exposed to direct sunlight.
Effect of Climate change on Rainforests
Climate Changeà Forest degradation à Food Shortages à Changing habitat àThreatened species
Changing climate leads to forest degradation:
- Scientists say that deforestation in the Amazon is pushing this ecosystem to a tipping point at which the forest will gradually turn into dry savanna.
- Once sufficiently degraded, the forest will lose its ability to generate its own rainfall.
- And after a series of devastating fires burned through the Amazon in 2019, this rainforest is inching ever closer to its dreaded tipping point.
Deforestation Leads to food shortages:
- About 2 billion people in the world rely on tropical rainforests for survival.
- Unfortunately, agriculture, both large- and small-scale farming, is responsible for the majority of tropical deforestation— which is accelerating climate breakdown.
- Studies show that since 1980 a decrease in annual rainfall due to the changing climate has created a steady decline of corn, wheat, soybeans and rice.
- This jeopardizes the livelihoods of local farmers, who depend on the crops commonly grown in the rainforest.
Degraded forests and food shortages result in an increased number of threatened species:
- Tropical rainforests are home to nearly 30 million species of plants and animals, which heavily rely on another for survival.
- As plant growth dwindles, these animals become vulnerable.
- In 2019, a landmark UN report revealed that nearly 1 million species face extinction due to human activities and climate change.
- When human activities accelerate climate change, species are going to try to follow those climates that are suitable for them rather than adapting to new ones.
- For many species, this requires moving upslope — but at a certain point, there will be nowhere left to go, which is what we call the escalator to extinction.
In order for the forest to be preserved, the underlying social, economic, and political reasons for deforestation must be recognized and addressed.
Once the issues are brought into the light, the decision can be made about what should be done. If it is decided that rainforests must be saved, then the creation of multi-use reserves that promote sustainable development and education of local people would be a good place to start.