Correct Option
The correct option is 2 only
Explanation
Global warming refers to the long-term rise in Earth's average temperature, which disrupts weather patterns, hydrological cycles, and ecological balances.
Statement 1 is Incorrect: Global warming intensifies the hydrological cycle, leading to higher rates of evaporation and more intense precipitation events. Furthermore, the melting of glaciers and the thermal expansion of ocean waters contribute to rising sea levels. These factors collectively increase the frequency and severity of both coastal and riverine flooding.
Statement 2 is Correct: Global warming does not eradicate insect-borne diseases; rather, it facilitates their spread. Warmer temperatures and altered rainfall patterns expand the geographical range and breeding season of vectors like mosquitoes into higher latitudes and altitudes, thereby increasing the incidence of diseases such as malaria and dengue.
Statement 3 is Incorrect: Climatic boundaries are not static. As global temperatures rise, isotherms shift poleward and upward in elevation. This forces climatic zones and their associated biomes (vegetation and wildlife habitats) to shift in order to remain within their optimal temperature and precipitation ranges.
Key Takeaway: Climate change exacerbates extreme weather events like flooding, expands the transmission range of vector-borne diseases, and causes dynamic shifts in climatic and ecological boundaries.