Which of the following is NOT an anthropogenic source of greenhouse gases?
1) decomposition of carbon-based garbage in landfills.
2) agricultural processes that add nitrogen to soils.
3) the burning of fossil fuels.
4) weathering of rocks.
The Correct answer and Explanation is :
The correct answer is 4) weathering of rocks.
Explanation
Anthropogenic sources of greenhouse gases are those that result from human activities, while natural processes occur without human intervention. Understanding the difference between these two categories is crucial in the context of climate change and global warming.
- Decomposition of carbon-based garbage in landfills: This is an anthropogenic source because it arises from human waste management practices. When organic matter in landfills decomposes anaerobically (without oxygen), it produces methane, a potent greenhouse gas that contributes significantly to global warming.
- Agricultural processes that add nitrogen to soils: This process is also anthropogenic. The use of synthetic fertilizers and other agricultural practices to enhance crop yields involves the addition of nitrogen compounds to soils. When these fertilizers break down, they release nitrous oxide (N₂O), another greenhouse gas with a global warming potential significantly greater than that of carbon dioxide (CO₂).
- The burning of fossil fuels: This is one of the primary anthropogenic sources of greenhouse gases. Activities such as driving cars, generating electricity, and heating homes all involve the combustion of fossil fuels, which releases CO₂ and other greenhouse gases into the atmosphere, exacerbating climate change.
- Weathering of rocks: This process is a natural, geological phenomenon and does not result from human activity. Weathering occurs over geological time scales and involves the breakdown of rocks through chemical, physical, and biological processes. While weathering can play a role in the carbon cycle by influencing carbon dioxide levels in the atmosphere over long periods, it is not classified as an anthropogenic source.
In summary, among the options provided, weathering of rocks is the only process that does not stem from human activities, making it the correct answer.