Overtourism, Carrying Capacity, and Sustainable Travel

Overtourism is the excessive growth of visitor numbers in a destination that harms the quality of life of residents, the environment and the experience of visitors; carrying capacity is the maximum number of visitors a place can accommodate without unacceptable damage; and sustainable travel aims to keep tourism within those limits. In brief: well-known cases include Venice, Barcelona, Amsterdam, Dubrovnik and Machu Picchu. Capacity can be physical (space), ecological (what nature can take), social (what residents and visitors will tolerate) and economic. Tools include visitor caps, entry fees, timed tickets, spreading visitors in time and space and better planning.

As travel has grown, some of the most popular places have become crowded and fragile. This guide explains the causes and signs of overtourism, how carrying capacity is defined and estimated, the Butler tourism life cycle, ways to manage visitors and travel more sustainably, compares the types of capacity in a table, works through calculations, outlines recent developments and corrects common mistakes.

What is overtourism?

The term became widely used around 2016–2017 to describe situations in which the number of visitors has a negative effect on residents and the environment. Signs include crowded streets and sites, long queues, rising rents and prices, loss of local shops replaced by souvenir stores, noise, litter, damaged monuments and protests by residents. The historic center of Venice, with about 50,000 residents, has received tens of millions of visitors a year, many of them day-trippers from cruise ships and hotels on the mainland, and in 2024 the city started trialing an entry fee for day visitors on selected days. Barcelona, Amsterdam, Dubrovnik, Santorini and Kyoto have also introduced restrictions, and in Thailand, Maya Bay was closed from 2018 until 2022 to recover from damage. Overtourism is related to the speed of growth, the concentration of visitors in a few places and times, cheap flights, cruise ships, social media popularity and short-term rentals. It affects not only cities but also national parks, mountains and islands.

What is carrying capacity?

The concept of carrying capacity comes from ecology. For tourism, it is the largest number of people who can use a place at the same time (or in a period) without damaging the environment, harming the local society or economy, or reducing visitor satisfaction. There are several types.

• Physical capacity: the number of people that can fit in a given space, such as the beds in hotels or people on a trail or in a museum.
• Ecological (environmental) capacity: the limit beyond which wildlife, plants, soils or water are damaged.
• Social (perceptual) capacity: the limit at which crowding reduces the quality of the visit or the tolerance of residents.
• Economic capacity: the point at which tourism begins to push out other economic activities or when costs of services outweigh the benefits.

In practice, capacity is not a single fixed figure. It depends on management, the behavior of visitors, the season and the values chosen, so planners often use “limits of acceptable change” and indicators that are monitored over time.

What is the tourism area life cycle?

Richard Butler proposed in 1980 that destinations develop through stages: exploration (few adventurous visitors), involvement (local services appear), development (rapid growth, outside investors), consolidation (growth slows, tourism dominates the economy), stagnation (capacity is reached, and the destination is less fashionable) and then either decline or rejuvenation if new attractions are created or growth is managed. The model explains why some resorts rise and fall, and suggests that action is needed before the capacity is exceeded.

How can destinations and travelers respond?

Destinations use visitor caps and permits (such as limits on daily numbers at Machu Picchu and the Galápagos), entry and tourist taxes (as in Venice and Amsterdam), timed tickets, limits on short-term rentals and cruise ship arrivals, spreading demand by promoting off-peak seasons and lesser-known places, and quality-over-quantity strategies, such as the daily Sustainable Development Fee in Bhutan, a country that follows a “high value, low volume” policy. Local residents should take part in decisions. Travelers can choose off-season or less crowded destinations, stay longer, travel by train, use local and certified businesses, respect local rules and avoid wildlife attractions that harm animals. Sustainable travel considers both the places visited and the emissions of getting there.

Types of capacity compared

Worked example: capacity and intensity

The values are hypothetical and illustrate common calculations.

1. Tourism intensity: a town of 40,000 residents receives 2,000,000 visitors a year. The ratio is 2,000,000 ÷ 40,000 = 50 visitors per resident per year.
2. Peak pressure: on a peak day in summer, there are 30,000 visitors in the old town. The ratio to residents is 30,000 ÷ 40,000 = 0.75 visitors per resident on that day.
3. Physical capacity of a site: a historic square covers 6,000 m². If each visitor needs 2 m² for comfortable movement, the physical capacity at one time is 6,000 ÷ 2 = 3,000 people. With an average visit of 1 hour and an opening time of 10 hours, the daily capacity is 3,000 × 10 = 30,000 visits.
4. Setting a cap: a footpath is 3 km long and 1.5 m wide (4,500 m²). If walkers should have at least 10 m² each for a pleasant experience, the capacity at one time is 450 people. If the walk takes 2 hours and the trail is open for 8 hours, then four turnovers allow 450 × 4 = 1,800 walkers a day.
5. Revenue from a fee: an entry fee of 5 paid by 1,200,000 day visitors raises 6,000,000. If 20% of day visitors are exempt, the revenue is 1,200,000 × 0.8 × 5 = 4,800,000.
6. Effect of off-peak shifting: if 15% of the 30,000 peak-day visitors can be shifted to quieter days, the peak is reduced by 4,500 to 25,500.

How has the issue developed?

Concern about crowding and capacity appeared in the 1960s and 1970s, when visitor numbers in national parks in the United States and in Mediterranean resorts rose sharply. The carrying capacity concept was introduced to tourism planning in this period, and Butler’s life-cycle model followed in 1980. Venice was a symbol of the problem from the 1980s. In 2017 and 2018, the term “overtourism” became widespread through media and protests in Barcelona, Venice and Amsterdam. The pandemic of 2020–2021 stopped tourism almost completely and offered a chance to rethink, and after the recovery of travel, many cities and countries introduced limits, taxes and new regulations. UN Tourism and other organizations promote “sustainable and resilient” tourism in line with the Sustainable Development Goals.

Which mistakes are common?

Mistake 1: Thinking that overtourism depends only on the number of visitors

It also depends on where and when they come, how they behave and how resilient the place and its community are. A site can be overcrowded at the busiest times while the same region has spare capacity.

Mistake 2: Expecting a single fixed carrying capacity

The capacity depends on management and on what limits are accepted, so it is better seen as a range that can change.

Mistake 3: Believing that fees alone solve crowding

Fees can reduce numbers and raise funds, but they work best together with other tools such as caps, timed entry and better planning, and they must be fair to residents.

Mistake 4: Seeing sustainable travel as only the destination’s responsibility

Travel choices, such as how far to travel, how long to stay and when to go, also affect the impacts at both ends of the journey.