Venice is currently facing a "double-threat" of subsidence (sinking) and over-tourism. Geologically, the city sits on a tilting tectonic plate and soft marshy soil that is naturally compacting, causing the city to sink by about 1–2mm per year. This is compounded by rising sea levels due to climate change, which has increased the frequency of "Acqua Alta" (high water) floods. While the MOSE flood barrier system has been highly successful since 2020 in preventing major flooding, it is a temporary solution that faces maintenance challenges and ecological concerns for the lagoon. Socially, Venice is in "trouble" because its local population is shrinking (now under 50,000) as residents are priced out by short-term rentals. In response, 2026 has seen the expansion of the Venice Access Fee (entry tax) for day-trippers on peak days to help fund the city's maintenance. While the city isn't going to "disappear" tomorrow—projections suggest parts could be submerged by 2150—the struggle to balance a living, working city with its status as a global museum remains its greatest challenge in the mid-2020s.