How does deforestation contribute to climate change?

DSSSB October 2024

English

Easy

Appeared in: DSSSB October 2024

Explanation

Forests act as massive 'carbon sinks,' absorbing carbon dioxide (CO₂) from the atmosphere during photosynthesis.
This absorbed carbon is stored for long periods in the trees' biomass (wood, leaves, roots) and in the forest soil.
Deforestation, through burning or the decay of cleared vegetation, releases this vast amount of stored carbon back into the atmosphere as CO₂.
CO₂ is a primary greenhouse gas; its increased concentration traps heat in the atmosphere, directly causing global warming and climate change.

Option B: This is factually opposite. Photosynthesis, the process carried out by trees, produces oxygen. Therefore, reducing the number of trees through deforestation leads to a decrease, not an increase, in atmospheric oxygen levels.
Option C: While deforestation does reduce transpiration (the release of water vapor from plants), which can alter local and regional rainfall patterns, this is not its primary mechanism for driving global climate change. The warming effect from the massive release of CO₂ is far more significant on a global scale.
Option D: Deforestation does not reduce the amount of sunlight reaching the planet. It removes the tree canopy, which actually increases the amount of direct sunlight hitting the ground. While this can change the surface's reflectivity (albedo), this effect is minor compared to the warming caused by CO₂ release.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Deforestation's role in the carbon cycle and climate change as background academic context rather than a clinical decision trigger.
Deforestation and climate change have significant indirect impacts on human health, including altered patterns of infectious diseases, respiratory issues from wildfire smoke, and food insecurity from changing agricultural conditions.
Nurses, particularly in community and public health roles, must be aware of the environmental determinants of health. Climate-related events like heatwaves, floods, and poor air quality can lead to increased hospital admissions and specific health emergencies.
What if? - If the question asked about the biggest health risk from the process of deforestation in Southeast Asia, the answer would likely shift from climate change to respiratory illness. The widespread use of 'slash-and-burn' techniques creates massive smoke haze, leading to acute and chronic respiratory problems in populations across the region.

How to Approach the Question

First, identify the core concepts in the question: 'deforestation' (the action) and 'climate change' (the outcome).
Recall the basic function of trees and forests in the global ecosystem. Remember that plants 'breathe in' carbon dioxide and 'breathe out' oxygen through photosynthesis.
Deduce that if trees absorb and store carbon, then removing them on a massive scale must cause that stored carbon to be released.
Connect this deduction to the concept of climate change. Recall that carbon dioxide (CO₂) is the most well-known greenhouse gas, responsible for trapping heat in the atmosphere.
Evaluate the options based on this logical flow. 'Releasing stored carbon dioxide' is a direct consequence of deforestation and a direct cause of climate change, making it the strongest answer.
Quickly dismiss the other options: deforestation reduces oxygen (making B incorrect), its effect on water vapor is secondary to CO₂ (making C less significant), and it doesn't reduce sunlight (making D incorrect).

Concept Tested & Keywords

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E6 Medicine Harrison 22e Part 2 p. 1650-1652