Even though tourism science has been dealing intensively with the topic of climate change for about 25 years, there remains a pressing need for further research to support the necessary transformation of the tourism sector to a sustainable undertaking [1]. The number of scientific publications has shown a clear upward trend in the last one and a half decades, with a sharp increase in the last eight years, including key adaptation literature on climate change affecting tourism [2,3,4,5], adaptation and carbon mitigation [6,7], policy [8,9], and sustainability [10,11]. Substantial research gaps exist, there seems to be a geographical bias on the developed part of the world, methodological weaknesses in determining tourism-related greenhouse (GHG) emissions along the value chain, and issues regarding equity [12,13]. Counteracting the geographical bias by its focus on small island developing states (SIDS), this interdisciplinary paper aims to provide a review of tourism development and the implications of its global emissions on the global climate, and links it with possible and already seen influences of climate change in the Pacific region to explain the growing vulnerability of the overall sector, with a particular focus on SIDS tourism in the Pacific region. The effects of the SARS-COV2 pandemic on international tourism and its consequences for the national development of Pacific SIDS complement the analysis. Case studies of two Pacific Islands present some evidence of current climate impacts, grounding the multiple risks small island nations and their tourism sectors face in the literature.

Operationally, the well-known, risk-based conceptualization of vulnerability resembles the analytic lens for this paper [14]. Linking disaster risk management and climate change adaptation, this framing can support the identification and prioritization of adaptation options and helps to strengthen resilience to changing conditions [15]. For this reason, this paper documents some of the observed impacts of climate change in two less researched, low-lying Pacific Island countries (PICs), i.e., Tonga and the Solomon Islands. This is complemented with future climate projections and linked with the development and challenges of international tourism, a sector that is a key pillar of national development in these islands. These islands are seldom investigated, so a concrete contribution to the literature is provided here.

2. Climate Change Impacts and the Tourism Sector

Climate and climate-related factors play a crucial role in the selection of tourist destinations, and in determining the season, the time of travel, and the length of stay [42,43]. Depending on the geographical location of the tourist destination and the type of touristic activity, climate change may therefore influence, i.e., impact, the tourism sector as a whole, and tourism activities in particular, in many ways. These can be differentiated according to environmental, socio-cultural, and economic dimensions. Regarding environmental impacts, for instance, the Himalayan ranges and the Tibetan plateau (high altitude regions in Asia) are currently facing glacier melting, glacier floods, and lake outbursts [44]. Furthermore, increased temperatures in some Middle Eastern countries have led to water shortages and increases in the frequency of heat waves, resulting in a decrease in tourism [45]. Winter tourism that is dependent on snow cover at mountainous resorts has also been impacted by alterations in the snow cover [46]. Concerning coastal and island tourism, slow-onset phenomena such as sea-level rise (SLR) and the warming of oceans as well as short-onset events such as flooding, high waves, and extreme weather events affect coastal areas and related marine attractions. Due to anthropogenic forcing, the global mean sea level is rising, and this rise is accelerating [47]. In 2019, the global mean sea level rose to 8.76 cm above the 1993 average, which resembles the highest annual average in the satellite record [48]. As sea-level rise is not uniform, it shows substantial regional variability, which, for example, leads to an intensified higher rise in the Western tropical Pacific Ocean [47] (p. 340). Some low-lying PICs have already disappeared [49,50,51]. Low-lying SIDS with long coastlines are susceptible to many impacts of global climate change; the inundation of low-lying coastal land, erosion of beaches and shorelines, and saltwater intrusion into freshwater lenses endangers coastal infrastructure, which is particularly crucial for those SIDS with few economic alternatives to tourism [47,52]. Concerning PICs, about 57% of their built infrastructure is located in risk-prone coastal areas [53]. The oceans and their sea life are other prominent tourism assets that are being affected. The world’s oceans (especially the upper 2000 m) in 2019 were the warmest in recorded human history [54]. The value of coral reef tourism was estimated to be 11.5 billion USD in 2010 [44,55]. Coral reefs are home to different organisms and endangered fish species. In 2010, ocean acidification already threatened about 60% of the world’s coral reefs [56]. Even if the global average temperature keeps within the 1.5 °C limit, climate scientists believe that coral reefs will decline by a further 70–90%; with a global temperature rise of 2 °C, almost all coral reefs are expected to disappear [57] (p. 10). Eco- or biodiversity tourism has also been gaining more attention. Urban tourists with a keen interest towards nature usually select these destinations [58]. Here, dry spells increasingly lead to forest fires. The Mediterranean basin, for example, is being affected by increased temperatures, reduced rainfall and variations in seasonal patterns [59,60]; in California, climate change has been at least partially responsible for forest fires [61]. The consequences for tourism must also be considered in a socio-cultural and economic context, which may weigh even more in destinations where, for example, a large share of the population depends on tourism as a main source of income. As sea levels continue to rise at a high rate, especially affecting the Pacific region, decision-makers are beginning to discuss adaptive migration, i.e., the relocation of entire villages and island populations, as a response to sea-level rise and other natural hazards [47,62]. Other consequences are a shrinking productivity and harvest, changes in seasonal patterns, rise in prices for basic foodstuff and consumer goods, widespread poverty as a consequence of disastrous events, increasing spread of diseases due to higher temperatures, shortages of fresh water supply, wars over gaining access to limited resources, heat impacts on human health and well-being, and a high cost of adaptation and mitigation measures especially in coastal areas [63]. The Table 2 below provides some examples of the socio-economic impacts of climate change on tourism.