11. Environment and sustainability

Humanity is causing a multitude of changes in the Earth's ecosystem, particularly as a result of economic activity over the last few centuries. In addition to the generally known increase in the concentration of CO₂ in the atmosphere and the resulting anthropogenic climate change, humans are influencing many other natural resources, such as the oceans and other bodies of water, biodiversity and soils. The following section deals with the use of soils and the change in this use from a natural area to an area used by humans. This change is referred to as land use change.

Land use change is a process that describes the conversion of land from one use to another. Initially, the original, natural landscape is converted into an area used by humans. This change can have a variety of causes, such as global population growth, the social changes that often accompany it (e.g. increasing urbanization and the expansion of transport networks) or the increasing demand for agricultural land. On the one hand, the latter is used for food production, which requires a constantly growing area of land to feed the world's population; reasons for this include population growth, eating habits (e.g. increased meat consumption and thus an increased need for arable land for growing animal feed) or other mismanagement of food resources (e.g. caused by wars or wasteful consumer behavior). On the other hand, these areas are also needed in the context of a bioeconomy for the cultivation of biomass for material use, such as cotton for the textile market, energy crops for the fuel market (e.g. oil palms or rapeseed) or lignocellulosic plants for the construction sector. The decisions we make in relation to land use have far-reaching consequences for the environment, society and the economy.

Two examples of these consequences are discussed below:

Currently, the most prominent example of land use change is probably the increasing deforestation of tropical rainforests. This is being cleared in order to be able to sell the valuable tropical timber at a profit on the one hand and to make the land usable for the cultivation of raw materials or as arable or grazing land on the other. This change in land use has a number of negative consequences for the environment. First of all, the nutrient-poor soils of the former rainforest are not suitable for permanent and sustainable agriculture, which is why the yield of the fields usually drops rapidly after around two to three annual harvests. This results in less vegetation on the land, which in turn causes increasing soil erosion. In addition, the deforestation of the tropical rainforest leads to a reduction in the habitat of a large number of animals, plants and insects, which ultimately leads to a loss of biodiversity with often unknown consequences. Furthermore, the rainforest is often referred to as the green lung of the earth because large amounts of CO2 are stored there and oxygen is produced. Any reduction in this area therefore leads to a reduction in the CO2 uptake potential and also to a partial release of the stored carbon. The following video provides a good summary of the history of deforestation in the Brazilian rainforest:

 

The destruction of the Amazon, explained

 

However, land use changes are also causing major environmental problems in Europe. Over the centuries, many moors and wetlands in Europe have been drained; the resulting fertile soils were then used as arable land. In their natural form, peatlands are a greenhouse gas sink; however, this effect is reversed when they are drained, as the peat substance is now decomposed by microorganisms. Furthermore, important biotopes are also destroyed in this case, thus reducing biodiversity.