Correct Option
The correct option is (a).
Explanation
Carbon dioxide (CO2) is a meteorologically and biologically significant gas, constituting approximately 0.036% of the Earth's atmosphere. It plays a crucial role in the heat budget of the Earth (Greenhouse Effect) and the biological carbon cycle involving photosynthesis and respiration.
Statement-wise Analysis
- Statement 1 is Correct: Carbon dioxide is essential for green plants. Through the process of photosynthesis, plants absorb carbon dioxide from the atmosphere to synthesize food (carbohydrates) and release oxygen.
- Statement 2 is Incorrect: In a natural cycle, the amount of carbon dioxide released by humans and animals through respiration is roughly equal to the amount consumed by plants, creating a natural balance. Describing the human contribution as "negligible" is factually inaccurate in the context of the carbon cycle's equilibrium. Furthermore, anthropogenic emissions (industrial) are significant enough to accumulate in the atmosphere.
- Statement 3 is Incorrect: The burning of fossil fuels, such as coal and oil, adds billions of tons of carbon dioxide into the atmosphere annually. Rather than maintaining the balance, this activity upsets the natural atmospheric balance, leading to an increase in global temperatures and climate change.
Key Takeaway
Carbon Dioxide is vital for photosynthesis and maintaining the Earth's temperature. However, the combustion of fossil fuels disrupts the natural balance between oxygen and carbon dioxide, leading to global warming.