Solution

According to the Intergovernmental Panel on Climate Change (IPCC) report titled ‘Climate Change 2021: The Physical Science Basis’, glacial retreat in the Hindu Kush Himalayas; compounding effects of sea-level rise and intense tropical cyclones leading to flooding; an erratic monsoon; and intense heat stress are likely to impact India in recent years.  Option 1 is correct. The Indian Ocean, which includes the Arabian Sea and Bay of Bengal, has warmed faster than the global average. The oceans factsheet released by IPCC indicates that sea surface temperature over Indian ocean is likely to increase by 1 to 2 degrees C (°C) when there is 1.5°C to 2°C global warming. The rapid warming of Indian Ocean would lead to powerful and intense cyclones in the region. Option 2 is incorrect. As per the IPCC report, heat extremes have increased while cold extremes have decreased, and these trends will continue over the coming decades over Asia. There are likely to be 90 to 120 days in a year with maximum temperatures above 35°C in case of 1.5 to 2°C global warming and over 180 days in case of 4°C warming. Option 3 is correct. Rainfall variability related to the El Niño–Southern Oscillation is projected to be amplified by the second half of the 21st century by the IPCC report. 2°C global warming has serious implications due to possible increases in extreme weather events like heat waves, heavy precipitation, intensification of tropical cyclones etc. Many regions are projected to experience an increase in the probability of compound events (i.e., different types of extreme events happening at the same time or one after the other). For example, drought followed by heat waves. Dry becomes drier and wet becomes wetter. This can be particularly alarming for India.