The question asks to identify the primary source of methane emissions within the agricultural sector. Methane is a potent greenhouse gas, and understanding its sources is crucial for climate change mitigation strategies. We need to evaluate each option based on its contribution to agricultural methane emissions.
Correct Option: C) Digestive processes in livestock
Ruminant animals such as cattle, sheep, and goats possess a specialized digestive system that includes a rumen. In the rumen, microbes break down complex carbohydrates through a process called enteric fermentation. This anaerobic process produces methane as a byproduct, which is then released into the atmosphere primarily through belching. This is a major global source of anthropogenic methane emissions, making it the main source within agriculture.
The question asks to identify the gas with the highest Global Warming Potential (GWP). GWP is a measure of how much energy the emissions of 1 ton of a gas will absorb over a given period of time, relative to the emissions of 1 ton of carbon dioxide (\(\text{CO}_2\)). A higher GWP indicates a greater warming impact.
D) Sulfur hexafluoride — Sulfur hexafluoride (\(\text{SF}_6\)) has the highest Global Warming Potential among the options provided, with a GWP of approximately 23,500 over a 100-year period. This means that 1 ton of \(\text{SF}_6\) traps 23,500 times more heat than 1 ton of \(\text{CO}_2\) over the same period.
The question asks to identify which of the given gases is removed from the atmosphere by UV radiation or bacteria. This requires knowledge of atmospheric chemistry and biogeochemical cycles.
C) Nitrous oxide is removed from the atmosphere by UV radiation through photolysis in the stratosphere, and to a lesser extent, by bacterial processes that convert it back to nitrogen gas.
The question asks how black carbon primarily contributes to atmospheric warming. We need to understand the physical properties of black carbon and its interaction with solar radiation and the Earth's climate system.
Correct Option: B) Absorbing sunlight and reducing albedo. This option accurately describes the two main mechanisms through which black carbon causes atmospheric warming: directly absorbing solar radiation in the atmosphere and, upon deposition, reducing the reflectivity (albedo) of surfaces like snow and ice, leading to more absorption of solar energy.
The question asks to identify the meaning of 'IndARC', a term sometimes seen in the news. This requires knowledge of India's scientific and research initiatives, particularly those related to polar regions.
D) India's underwater observatory to scientifically study the Arctic region
IndARC is indeed India's first multi-sensor moored observatory deployed in the Arctic, specifically in the Kongsfjorden fjord, Svalbard, Norway. It was launched in July 2014. Its primary objective is to collect data on the Arctic environment to understand climate change, oceanographic processes, and their impact on the Indian monsoon.
The question asks us to identify the correct statements regarding the Indian Ocean Dipole (IOD) in the context of Indian monsoon forecasting. We need to evaluate each statement based on the scientific understanding of IOD and its interaction with other climate phenomena like El Niño.
B) 2 only. Statement 1 is incorrect because IOD involves the Indian Ocean, not the Pacific Ocean. Statement 2 is correct as IOD can modify the influence of El Niño on the Indian monsoon.