Human development, such as population growth, progress of social structure, and growth of individual needs, are the driving forces that induce the anthropogenic environmental pressures causing loss of biodiversity. Natural processes may also exert environmental pressures on components of biodiversity.
Major types of pressures affecting biodiversity are:
Important natural processes are climatic fluctuations and disturbances, such as fire, erosion, floods or avalanches, grazing, browsing, and tree felling (by storms as well as by beavers or elephants). They are regular components of many ecosystem processes. While they are detrimental for directly affected individuals, species, or habitats, they usually increase biodiversity by triggering successions leading to habitat and niche diversification. In contrast, anthropogenic environmental pressures often lead to a reduction or simplification of biological diversity, from genes to biomes.
- Habitat loss, fragmentation, or degradation due to land use;
- Climate change due to greenhouse gas and aerosol emissions, leading to change of habitats and species distribution ranges;
- Overexploitation of ecosystem resources, both biotic, such as fish stocks, game animals, grass (through overgrazing), and wood (by deforestation), and abiotic, such as inadequate water use for irrigation;
- Release of nutrients, accelerating eutrophication of water bodies;
- Release of synthetic chemicals and radioactive material into natural ecosystem, having direct or indirect effects on biodiversity;
- Introduction of alien species, some of which may become invasive and considerably change natural ecosystems.