Water

Karst aquifers supply drinking water to nearly 20% of the world's population and contain about 25% of global groundwater reserves, but are highly vulnerable to pollution.

IAH Commission on Karst Hydrogeology

UN Water Conference 2023 paper

World Karst Aquifer Map

Biodiversity

Caves represent critical ecosystems that house specialized and fragile species. Animals use caves periodically, e.g., for hibernation, or stay in caves for their whole life cycles. Subterranean fauna is often blind, lacking pigment, and highly specialized. It depends on the stability of these environments and is highly vulnerable to disturbance.

IUCN SSC Cave Invertebrates Specialist Group

International Society for Subterranean Biology (ISSB)

International Cave Animal of the Years

Geoheritage

Some of the Earth’s most dramatic landscapes are in karst areas where landforms commonly include sinking streams, blind and dry valleys, closed depressions, underground drainage and caves. Cave contents include speleothems like stalactites, stalagmites, helictites, gypsum flowers, flowstones, crystals, draperies or rimstones, or any other natural mineral formation or deposits, and sediments.

IUCN / WCPA Geoheritage Specialist Group 

IUCN Guidelines for geoconservation in protected and
conserved areas

Archives

Caves preserve natural archives, paleontology, and archaeology. They contain animal remains such as fossils, bones, teeth, pollen, insect remains, or traces produced by the use of caves as shelters and feeding places.
Human artifacts include paintings, sculptures, tools, food remains, excrement, charcoal, and deliberate placements of rocks and bones.

Cultural Heritage

Caves contain some of humanity’s oldest archaeological sites, sacred places, and artistic expressions. Throughout human evolution, caves have functioned as refuges, burial sites, and sacred places. They preserve cave paintings, rock carvings, and ritual spaces of immense anthropological significance. 

Climate 

Karst plays a vital role in climate regulation through longterm carbon sequestration—via carbonate rock dissolution, speleothem formation, and organic carbon storage in soils and aquifers. These systems also preserve organic carbon in soils and aquifers. Sediments and mineral formations in caves preserve archives of past climate change, informing adaptation strategies. 

Environmental Risks

Karst aquifers offer minimal natural filtration, which makes them highly susceptible to rapid contamination. Pollutants from agriculture, industry, or urban runoff can travel long distances and impact drinking water. Excesssive groundwater withdrawal from karst can lead to subsidence or catastrophic collapse on the surface. Those sinkholes, both natural and anthropogenic, occur frequently in karst regions, creating land instability and posing threats to infrastructure and lives.

Endangered Caves and Karst 

Caves and karst are vulnerable and sensitive features, and human activities like construction, such as infrastructure and raw material extraction in quarries and mines, destroy them. Landfills and other forms of pollution endanger caves, groundwater, and their ecosystems. 

IUCN/WCPA GSG Caves and Karst Working Group

IUCN Guidelines for Cave and Karst Protection

IUCN Listing of 76 Recommendations for Cave and Karst Protection

Tourism

In addition to show caves, there has been an increase in tourism activities on bare surface karst, including areas of limestone pavement, pinnacle karst, cliffs, and canyons. Iconic sites like World Heritage Sites (WHS) attract millions annually and require careful management. Connectivity between the underground and surface makes karst systems especially vulnerable to human activities.

 CaveMAB Network

Economic value 

Local livelihoods, such as agriculture, tourism, and construction, depend on healthy karst systems.Karst supplies around 10 % of the world's population with water. The natural beauty of landscapes and wildlife attracts visitors and generates income for local people. Research shows that cave microorganisms can be helpful in the development of medicines.

Space Exploration Analogues

Karst caves mirror some conditions on the Moon and Mars, where lava tubes and subsurface voids have been observed. Earth caves are used for astronaut training, robotic exploration trials, and studies in astrobiology, helping prepare for future missions. Such analogues support not only astronaut training, but also the development of autonomous technologies for planetary exploration.