F2 What is greenhouse effect?

The process of greenhouse effect

1. a greenhouse allows all _______________ incoming sunlight to pass through but
2. blocks【阻止】 the passage【通道】 of _______________ outgoing heating energy
3. the trapped heat leads to【導致】 the _______________ rise of temperature inside the greenhouse

The atmosphere【大氣層】 is a natural greenhouse. Greenhouse gases in the atmosphere such as _______________ water vapour, _______________ carbon dioxide, methane【甲烷】 and nitrous oxide【氧化亞氮】 absorb【吸收】 _______________ heat from the Earth.

The level of greenhouse gases【溫室氣體水平】 has increased markedly【明顯地】 since 20th century, resulting in _______________ global warming, which causes【導致】 _______________ climate change.