6 - 森林面積減少
1Cause
Deforestation is due for 80% to agriculture. It can be considered as a human activity or as a consequence of agriculture of both.
1Consequence
It's written on card 7!
5Other possible causes
Deforestation can be considered either as a human activity, or as a consequence of agriculture, or both.
This link is possible for wood-consuming industries. However, wood used by a factory in a sustainably managed forest would not be considered as deforestation.
It can be said that heating buildings with wood is in part responsible for deforestation, but it is not significant. Neither is building a major cause of deforestation. Agriculture is the main cause of deforestation, way in front of buildings and their usage.
Road construction sometimes requires deforestation, but the one-dimensional aspect of the road makes it almost negligible compared to deforestation linked to agriculture.
Deforestation is partly done by burning the forest, which can then degenerate into uncontrolled fire. This is what happened in the summer of 2019 in the Amazon and Australia.
7Other possible consequences
Participants often think that deforestation reduces carbon sinks. In reality, the impact is minimal because deforested areas represent a very small part of the total forest area. Moreover, a mature forest has reached its equilibrium and no longer absorbs carbon. Therefore, as mainly mature forests are deforested, this does not impact carbon sinks. On the other hand, the amount CO2 released is very high.
Deforestation can perturb local precipitation.
Vegetation retains water. Cutting it down can lead to flooding.
Deforestation can be the direct cause of droughts because trees stock a lot of water. If they are cut down, they no longer play their part as humidity regulators.