Environmental degradation

Environmental degradation is the deterioration of the Earth's natural systems. It occurs when resources like air, water, and soil are depleted. This process also includes the destruction of ecosystems and habitats. It can lead to the extinction of wildlife and widespread pollution. Scientists define it as any change that is considered harmful or undesirable. This degradation is a major global concern. The United Nations identifies it as one of ten official threats. It reduces the capacity of the environment to meet social and ecological needs.

Degradation happens through both direct and indirect processes. Direct degradation is often easy to see. An example is deforestation, where large areas of forest are cleared. Indirect processes are harder to notice immediately. Plastic pollution can build up in the environment over long periods. The buildup of greenhouse gases can also cause damage. These gases can push the climate system toward tipping points. Once these points are reached, the environmental impact is amplified. This creates lasting changes that are difficult to reverse.

One of the most serious forms of degradation is biodiversity loss. Biodiversity refers to the variety of life in a particular habitat. Human activity has significantly altered the planet's biological makeup. Since the start of agriculture 11,000 years ago, humans have changed 70% of Earth's land. This has reduced global vegetation biomass by half. Terrestrial animal communities have also seen a 20% decline in biodiversity. A 2020 report found that human activity destroyed 68% of vertebrate wildlife since 1970. Scientists suggest human activity has pushed Earth into a sixth mass extinction event.

The loss of species impacts essential ecosystem services. These are the natural processes that support life. For example, pollinators like bees help plants grow. Soil organisms keep the ground healthy for farming. When habitats are destroyed, these services decline. This affects food security and the supply of freshwater. Many species that control pests or provide food are also in decline. In 2019, the IPBES reported that roughly one million species face extinction. This is largely due to industrial agriculture, livestock rearing, and overfishing.

Water degradation is another critical component of environmental decline. Fresh water is a vital resource for all life on Earth. However, only 2.5% of all water on Earth is fresh water. Most of that is frozen in ice caps in Antarctica and Greenland. This leaves only a tiny fraction available for human use. Currently, 85% of fresh water is used for irrigation. Another 6% is used for domestic purposes like bathing. Industrial uses account for about 4% of consumption. One in three people globally already faces water shortages.

Climate change significantly alters the global water cycle. As mean global temperatures rise, evaporation rates change. This affects how much water reaches groundwater supplies. Warmer winter temperatures can reduce the winter snowpack. This leads to less water being available during the summer months. In mountain regions, rising temperatures cause glaciers to melt rapidly at first. Eventually, the glaciers retreat and the total water supply decreases. This creates a cycle of flooding followed by severe droughts.

Rising temperatures also affect the quality of water. Warmer water can lead to increased bacterial growth. It can also decrease the amount of dissolved oxygen in the water. This change can harm aquatic ecosystems and the species within them. Additionally, rising sea levels can cause saltwater intrusion. This happens when salt water pushes into freshwater reservoirs and aquifers. This process makes coastal freshwater supplies much harder to use. These changes create a complex web of environmental challenges for the entire planet.