The Major Environmental Crises Today
Climate Change: The overarching boundary tracking greenhouse gas concentrations and global temperature rise.
Biosphere Integrity: Relates to the loss of biodiversity and the extinction of species, affecting overall ecosystem health.
Stratospheric Ozone Depletion: The thinning of the ozone layer, which protects the Earth from harmful UV radiation.
Ocean Acidification: The lowering of ocean pH levels caused by the absorption of excess carbon dioxide, threatening marine life.
Biogeochemical Flows: The disruption of natural cycles, particularly the overloading of nitrogen and phosphorus (often from agricultural fertilizers).
Land-System Change: The alteration of the Earth’s land surface, primarily through deforestation and the conversion of natural habitats for agriculture or urban use.
Freshwater Use: The global consumption and extraction of water from lakes, rivers, and groundwater.
Introduction of Novel Entities: The release of synthetic chemicals, heavy metals, microplastics, and genetically modified materials into the environment.
Atmospheric Aerosol Loading: The emission of microscopic particles and air pollutants that affect cloud formation, precipitation, and the climate
Several of these boundaries have already been crossed, including:
- Climate change
- Biodiversity loss
- Land-system change
- Biogeochemical flows
- Novel entities (chemical pollution)