Narrator: Listen to part of a lecture in an environmental science class. Professor: Today we're going to discuss a surprising factor in climate change: the role of forests. Most people think trees simply absorb carbon dioxide, which is true. But recent research shows that forests also release compounds called biogenic volatile organic compounds, or BVOCs. These compounds can react with other pollutants in the atmosphere to form aerosols, tiny particles that reflect sunlight back into space. This reflection, in turn, can cool the planet. However, the effect is complex. In some regions, BVOCs can also contribute to the formation of ozone, a greenhouse gas. So, forests act as both a carbon sink and a source of cooling particles, but the balance depends on local pollution levels. For instance, in pristine areas, the cooling effect dominates. But in polluted areas, the interaction can actually warm the atmosphere. This means that reforestation projects must consider local air quality to maximize benefits.
❓ Вопрос What is the main point the professor makes about forests and climate?
A. Forests only help cool the climate by absorbing carbon dioxide.
B. Forests have both cooling and warming effects on climate, depending on local conditions.
C. Reforestation projects always reduce global warming regardless of location.
D. BVOCs from forests are harmless and have no impact on the atmosphere.
✅ Правильный ответ
Forests have both cooling and warming effects on climate, depending on local conditions.
TOEFL Listening Tips
Skim the questions first to predict the content
Watch for signal words in lectures and conversations (however, actually, in fact)
For main idea questions, focus on the beginning; for detail questions, focus on examples and data
For attitude questions, pay attention to the speaker's tone and word choice
Take notes on keywords; don't try to write down every word
