Geodiversity, as noted before, is a collective term for the planet’s abiotic diversity [1]. Early attention to the term as a benchmark for the protection of abiotic natural elements (i.e., mainly landforms and areas that feature them) can be traced back to the late 1980s and early 1990s, with notable examples from Australia and the UK ^[1][2][1,31]. Since its early days, the term has been seen as a partial response to the overemphasis on biodiversity in nature conservation research and practice and as an important concept that alludes to the totality of nature including its biotic and abiotic components [1]. Geodiversity sometimes has also been aligned with the concepts of ‘natural capital’ and ‘ecosystem services’ ^[3][4][32,33]. Global natural capital databases enlist abiotic elements such as geology, air, and water as fundamental assets for humanity ^[5][34], and there is widespread recognition of the fact that our planet’s abiotic diversity supports a number of materials and flows, i.e., ‘services’ that are vital for the human society—akin to the benefits or ‘services’ derived from healthy ecosystems. In a recent paper, Gray (2018) pointed out that most notable ecosystem services literature to date either excludes geodiversity and the benefits we derive from it or only refers to the term in a limited and partial manner ^[3][32]. It was proposed therein that the positioning of geodiversity and biodiversity should be equal when their contribution to the total stock of natural capital is taken into account, and that geosystem services should be seen as equally important as ecosystem services (with some instances of overlap between the two).

Three other facets regarding geodiversity are worth looking at for understanding its important role for informing conservation science, sustainability studies, and sustainable tourism research. These are: (i) geodiversity is not merely about impressive landforms that count as ‘heritage’, but also involves a multitude of earth processes, and is therefore dynamic in nature [1]; (ii) geodiversity underpins biodiversity—though not a rule of thumb, it is more often the case that diversity in landforms and processes results in diverse ecosystems and species richness ^[6][7][35,36]; (iii) geodiversity has an element of ‘geological time’ which is much older in scale than that which humans experience ^[8][37]. Thus, geodiversity can be seen as an emerging concept in nature conservation research that speaks for the equal importance of nonliving nature. A particularly important facet of geodiversity regarding nature conservation is the fact that the term is planetary in scope and speaks for the intrinsic value of planetary processes and heterogeneity ^[1][2][1,31].

In practice, geodiversity has mainly gained traction in protected area (henceforth PA) management, particularly at UNESCO World Natural Heritage (henceforth UNESCO WNHS) and UNESCO Global Geoparks programs. There are many locations where geodiversity is referred to or incorporated within the management of sites as part of these programs, and an academic journal (Geoheritage) regularly features such examples. Some instructive examples include the Gea Norvegica Geopark (Norway), which is based on a geological continuity of 1.5 billion years and the meeting point between older Scandinavian and newer European geological landmasses ^[9][38]; Beigua Geopark (Italy), where impressive examples of oceanic crust affected by alpine orogeny can be seen and there are various research, conservation, and communication programs to communicate the value of geological heritage ^[10][39]; Azores Geopark (Portugal), where geodiversity formed by several types and stages of volcanism can be observed ^[11][40]. However, while geoparks as an international initiative makes the most obvious reference to geodiversity, particularly in regard to tourism ^[12][13][41,42], it was pointed out that geopark designations are not adequate for conserving geodiversity on larger scales ^[14][43]. World Natural Heritage Sites (WNHS) also refer to geodiversity—a total of 93 WNHS are inscribed due to their representativeness of major stages of the planet’s history, land formation, and natural and physiographic processes ^[15][44]. Some notable examples include the Joggins Fossil Cliffs ^[16][45] and Mistaken Point ^[17][46] in Canada and the Giant’s Causeway and Causeway Coast in the UK ^[18][47]. Due to their enhanced level of protection, it can be argued that the UNESCO WNHS provide the most robust legal and societal engagement to protect geodiversity features. However, so far, their most prominent role has been to celebrate the diversity features they contain, and many WNHS are popular tourism destinations. It is argued here, with reference to the aforementioned works and what follows in subsequent sections, that internationally protected geodiversity-rich locations such as the WNHS have the additional and vital role of speaking for the integrity and diversity of nonliving nature. Needless to say, all internationally recognized protected areas can serve towards the safeguarding of geodiversity and should be augmented by national or sub-national level-protected landscapes wherever appropriate.

Of late, “geotourism” has emerged as an important concept in contemporary tourism discourse and praxis ^{[19][20][21][22]}[48,49,50,51]. Geotourism was initially defined by Dowling and Newsome (2006) as a niche type of tourism that is practiced in natural areas and is oriented towards geology, geomorphology, and landscapes ^[19][48]. This strand of definition subsequently became more inclusive in terms of target areas (i.e., not only limited to natural areas) and activities (i.e., either guided tours with explanations of geological features or personal visits out of interest) ^[20][49]. A notable early attempt by Hose (1995) posited geotourism as a form of tourism that enabled tourists to understand the geology and geomorphology of the destination and thus enabled an earth-science-based understanding of the place beyond immediate aesthetic appreciation ^[23][52]. Later, Hose (2012) expanded on the mandate of geotourism by proposing a ‘3G’ model where the three Gs stand for “Geoconservation”, “Geohistory”, and “Geo-interpretation” ^[24][53], showing that geotourism has a fundamental task of at least conserving those expressions of geodiversity that qualify as heritage attractions. However, while the definition of geotourism has continued to expand, perhaps unintentionally, its core focus has become somewhat diluted. Early indications of this dilution came from the attempts by the National Geographic Society that sought to include ecological and cultural elements and broadened the scope of geotourism even further to encompass various geographical characteristics of place ^[22][25][51,54]. Currently, the National Geographic Society espouses 13 principles for geotourism, which, geared towards sustainable destination stewardship as they are, primarily speak for the instrumental values of recreation and local socioeconomic benefit ^[26][55]. With regard to the overall evolution of the concept, the recent compilation by Dowling and Newsome (2018) succinctly describes that, over the years, geotourism has expanded from being a ‘type’ of tourism (i.e., referring to its core of geological/geomorphological features as attractions) to an ‘approach’ of tourism (i.e., one that incorporates different geographical areas of interest as well as a spectrum of activities) ^[22][51].

Thus, as the preceding discussion shows, geotourism started off as a geologically focused form of tourism but moved towards a more generic spectrum of activities. While initial key works mentioned the centrality of geology, geomorphology, and the natural aspects of the landscape and the processes that were creating those features (or, in other words, geodiversity) ^[19][48], over the years, geotourism has somewhat outgrown its core focus and mandate, and it now incorporates many facets other than geodiversity ^[22][51]. While a full analysis of geotourism, its characteristics, competing definitions, and practice examples is beyond the scope of this position paper and can be found elsewhere ^{[19][20][21][22][27]}[48,49,50,51,56], it remains to be noted that, while geotourism has emerged as a new and promising paradigm in tourism related to the earth, its core focus today has been somewhat diluted, and a range of activities occurring in both natural and human-modified areas currently qualify as geotourism ^[22][51]. While this development may have expanded the scope of geotourism and the diversity of its contents, it also implies that the mandate of conserving geological/geomorphological features and processes with the full range of their diversity and natural extent ^[1][28][1,57] has been diffused to an extent.

As briefly touched on in the preceding section, the UNESCO Global Geoparks program is one of the more prominent international schemes that celebrate earth heritage. The Global Geoparks concept formally took shape in 2004 with 17 geoparks from Europe and 8 from China and eventually became a formal UNESCO initiative in 2015. Currently, there are 177 Global Geoparks in 46 countries and regions ^[29][58]. Nearly all geoparks connect to geodiversity through the visitation of attractions that may include important outcrops, landforms, fossil beds, and entire landscapes that showcase earth processes, and that, in many cases, also include examples of in situ conservation in the form of geosite designation and ex situ conservation in the form of museums and visitor centers ^[30][59]. UNESCO defines its Global Geoparks as “…single, unified geographical areas where sites and landscapes of international geological significance are managed with a holistic concept of protection, education and sustainable development” ^[29][58]. On the UNESCO website, the main foci of geopark activities are listed as ‘Natural Resources’, ‘Geological Hazards’, ‘Climate Change’, ‘Education’, ‘Science’, ‘Culture’, ‘Women’, ‘Sustainable Development’, ‘Local and Indigenous Knowledge’, and ‘Geoconservation’ ^[31][60]. While this inclusive list upholds many good practices, it conspicuously does not feature geodiversity itself as a standalone focus. A further look into the ‘Geoconservation’ aspect reveals that the main concern here is protection of specific geological/geomorphological sites within geoparks and not the protection/conservation of geodiversity as a whole and at the planetary level. Nonetheless, there are examples of ongoing activities within UNESCO’s Global Geoparks that prioritize geodiversity, as some examples cited in the previous section show ^[9][10][11][38,39,40].

Apart from the UNESCO, the International Union for Conservation of Nature (IUCN) is a key international body that has started to focus on geodiversity and the benefits it extends to biodiversity in protected areas ^[28][57]. Several IUCN resolutions currently recognize the value of geodiversity in underpinning biological, cultural, and landscape diversity and, since 2014, the IUCN has organized a Geoheritage Specialist Group (GSG) as a part of its World Commission on Protected Areas (WCPA), which is expected to promote geodiversity management and advice on geodiversity/geoheritage-related aspects in WNHS nominations ^[28][57]. In addition, there are several emerging examples of how geodiversity is being seen as key for geotourism and local resource management in protected areas in different parts of the world ^[30][32][59,61].

While these developments are commendable, as pointed out by Gordon et al. (2018), geodiversity and geoheritage are still poorly recognized and insufficiently integrated in protected area management in general ^[28][57]. The foregoing discussion in this papentryr also reflects this reality. Despite the emergence of geotourism as a powerful new paradigm that helps to connect with the earth and register many areas under the UNESCO Global Geoparks scheme, there is much room for improvement and exploration regarding the integration of geodiversity as a focal point in protected area management, and on how tourism could be fruitfully engaged with geodiversity.