The US Geological Service estimates that Bolivia has 5.4 million cubic tonnes of lithium, which represent 50%–70% of world reserves. However, to mine for it would involve disturbing the country's salt flats (called Salar de Uyuni), an important natural feature which boosts tourism in the region. The government does not want to destroy this unique natural landscape to meet the rising world demand for lithium. On the other hand, sustainable extraction of lithium is attempted by the government. This project is carried out by the public company "Recursos Evaporíticos" subsidiary of COMIBOL.