Advanced Placement (AP) Biology Practice Exam

What effect does water's high specific heat have on the Earth's climate?

1. It increases seasonal temperature variations.

2. It moderates the temperature of coastal areas.

3. It causes extreme weather conditions.

4. It decreases the rate of evaporation.

The correct answer is: It moderates the temperature of coastal areas.

Water's high specific heat means it can absorb a significant amount of heat before its temperature begins to rise. This property plays a crucial role in moderating the Earth's climate, particularly in coastal areas. When the temperature of the surrounding air rises, bodies of water can absorb excess heat without experiencing drastic temperature changes. This leads to more stable temperatures for nearby land areas, resulting in milder climates. During the day, for example, water warms up slowly compared to the land, preventing extreme heat conditions, while at night, the water releases stored heat slowly, keeping the coastal areas warmer than they would be otherwise. This moderation of temperature helps maintain a more consistent climate pattern near bodies of water, contrasting with the more variable climate found in inland areas where land heats and cools more rapidly.