Q5B · Explain how global climate change is linked to the increasing frequency and intensity…

Answer

1. Anthropogenic greenhouse warming. A warmer climate increases many heat extremes and changes the moisture available for heavy rain. For example, a higher temperature baseline makes an unusually hot period more likely to exceed a harmful heat threshold. This is a mechanism example, not attribution of a particular heat wave to one cause.
2. Ocean and atmospheric variability. Patterns such as El Niño redistribute heat and influence atmospheric circulation. For example, El Niño can contribute to deficient rainfall in some regions and heavy rainfall in others; it does not produce the same weather everywhere or guarantee an Indian drought.
3. Land-use change. Deforestation and sealed urban surfaces can alter local heat and runoff. For example, replacing vegetation with dark paving reduces shade and evaporative cooling, worsening local heat exposure. This local influence should not be confused with the global greenhouse driver.
4. Persistent weather and local feedbacks. Long-lived circulation patterns and feedbacks can sustain extremes. For example, a persistent high-pressure pattern can suppress rain and maintain heat; drying soil then reduces evaporative cooling and amplifies the hot conditions.

A warmer atmosphere can hold more moisture and contribute to heavier rainfall when weather conditions support it. Intense rain over saturated or sealed catchments can produce flooding. In other regions or seasons, rainfall deficits and greater evaporative demand can intensify drought. These are compatible outcomes: more variable water availability can produce wet extremes and dry extremes in different places or times. Urban expansion and water use also shape the disaster impacts.