Q.Explain any three characteristics of ‘Phase II’ of growth of population in India.

Climate Impact on Population: From Intuition to Precision

Think about where people live. The vast majority of humanity clusters in regions that are neither too hot nor too cold, neither too dry nor too wet. The world's great cities — Mumbai, Shanghai, New York, London — all lie in climate zones that support agriculture, provide reliable fresh water, and avoid extremes that make daily life dangerous.

Now imagine the opposite. The Sahara Desert, the Siberian tundra, the high Himalayas. These places have tiny populations despite covering enormous land areas. The reason isn't that people dislike beautiful landscapes — it's that the climate makes survival difficult, expensive, or impossible without modern technology.

That's the core intuition: climate sets the stage for where human populations can thrive, and changes in climate can force populations to shrink, move, or adapt.

The Precise Statement

This is not a single effect but a bundle of mechanisms:

1. Carrying capacity of the land. A region's climate determines how much food can be grown, how much water is available, and what diseases are prevalent. A monsoon climate supports dense rice-farming populations; a desert climate supports only sparse pastoralist communities. The relationship is direct: more favourable climate → higher carrying capacity → larger possible population density.

2. Extreme events and mortality. Cyclones, floods, heatwaves, and droughts kill people directly. But they also destroy infrastructure, contaminate water supplies, and ruin harvests — leading to indirect deaths from disease and starvation. A single extreme event can reverse years of population growth in a region.

3. Long-term shifts and migration. When a region's climate changes — becoming drier, hotter, or more unpredictable — people move. This is not a new phenomenon. The Dust Bowl of the 1930s in the American Great Plains drove 2.5 million people out of the region. Today, sea-level rise and desertification are creating climate refugees across South Asia and Sub-Saharan Africa.

4. Health and fertility. Climate affects disease vectors (mosquitoes carrying malaria and dengue thrive in warmer, wetter conditions). It also affects agricultural labour productivity and child mortality — both of which influence fertility rates. In harsh climates, families often have more children to compensate for higher child death rates, creating a complex feedback loop.

A Concrete Example: The Sahel Region

The Sahel — the semi-arid belt south of the Sahara — illustrates all these mechanisms at once.

Over the past 50 years, rainfall has become more erratic and droughts more frequent. The carrying capacity of the land has fallen. Crop failures have become common. This has led to:

• Higher child mortality (from malnutrition and disease) …