Give biological reasons for the following statements:
Cutting of trees should be discouraged.
Topic: Deforestation and global warming
Answer
Because trees ABSORB CARBON DIOXIDE during photosynthesis. Cutting them down leaves more carbon dioxide in the atmosphere, which intensifies the GREENHOUSE EFFECT and causes GLOBAL WARMING. Trees also release oxygen, trap dust, hold the soil against erosion, maintain the water table and provide habitats for wildlife.
The GLOBAL WARMING link is the strongest single reason and should come first, since it names a mechanism rather than a general good.
NOTE HOW DEFORESTATION WORKS FROM THE OTHER DIRECTION than burning fuel: burning fossil fuels ADDS carbon dioxide, while cutting trees REMOVES WHAT WOULD HAVE TAKEN IT AWAY. Both raise the atmospheric level, but by opposite routes — worth saying if you have room.
Other consequences worth a clause: soil erosion and landslides, falling water tables, more frequent floods, and loss of biodiversity.