OCR General Certificate of Secondary Education (GCSE) Biology Practice Exam

How do water evaporation from the forest canopy affect the climate?

1. It creates localized hurricanes

2. It generates clouds and rain, cooling the air

3. It increases ground temperatures

4. It disrupts normal weather patterns

The correct answer is: It generates clouds and rain, cooling the air

Water evaporation from the forest canopy plays a significant role in influencing climate conditions. When water evaporates from leaves and other surfaces in a forest, it enters the atmosphere as water vapor. This process not only provides moisture to the air but also contributes to a cooling effect. As the water vapor rises, it can condense to form clouds, which subsequently may lead to precipitation, such as rain. This cycle is vital for maintaining local humidity and temperature levels. The generation of clouds from evaporation helps reflect sunlight, which in turn contributes to cooling the air underneath. Therefore, the overall effect of evaporation from the forest canopy is the generation of clouds and rain, helping to regulate local temperatures and maintain a balanced climate. Other options do not accurately represent the primary impact of evaporation from forest canopies. For example, while localized hurricanes, increased ground temperatures, and disruption of normal weather patterns can occur due to various weather phenomena, they are not direct results of the evaporation process from forest canopies. Instead, the cooling effect and contribution to precipitation are key factors that highlight the importance of evaporation in climate regulation.