How does human population growth affect the biosphere?
1 Answer
More people means higher demand for resources and agricultural land to feed more people and so the biosphere gets impacted.
Explanation:
The original biomes on Earth look much different than todays. See pic. 1
As populations soar, the first impact to the biosphere tends to be expansion of agriculture to feed a growing population. This changes the natural biomes to human biomes such as rangeland for cattle, agriculture for growing food crops. In fact, almost all of the original biomes have now been impacted by food production.See pic 2. This also happens in marine ecosystems as overfishing tends to happen along continental shelf regions to satisfy raising demand.
As populations become more affluent, there is a greater demand for natural renewable and non-renewable resources. Timber is in demand for housing, and so forest ecosystems decline. Demand for cars rises and so the demand for steel, metals, rubber and petroleum increase along with the impacts they have on the biosphere. This in turn, creates more demand for roads and other infrastructure, which means more cement quarries must be opened - further impacting ecosystems. Its also been shown that as people become more wealthy, they like to eat more beef and other meats. This in turn, means more land must be converted to grazing land for cows, sheep, and so on.
Then, as people become more affluent they demand more luxury items that further impact biomes. For example, growing wealth in China has now created a renewed demand of elephant ivory to make various "trinkets" leading to a further decline in elephants and more illegal poaching. Demand for fine wines leads to more grape vineyards being planted and further displacing native species of plants. And so it goes......
