Planetary Boundaries and Ecosystem Services

Greetings, welcome and salutations to all the readers, travellers and curious minds!

Now, before delving into some of the global environmental issues associated with tourism, I thought I’d outline a couple of important concepts that will come in useful when thinking about tourism’s impact on the environment.

Planetary Boundaries

The first is the recently updated framework of planetary boundaries, which essentially lays out a “safe operating space” for societal development. The framework proposes boundaries for the anthropogenic influence on nine key biophysical processes regulating the Earth’s systems stability (Figure 1). Figure 1 illustrates the current state of affairs; past the “danger” end of the yellow zone of increasing risk, there is a vastly increased chance of change to the Earth system's functioning. Already the anthropogenic alteration of 4 of these Earth system processes exceeds the proposed planetary boundary. Evidence of this increasing transgression of boundaries comes, for example, from the rising intensity and occurrence of numerous extreme weather events under the influence of increasing atmospheric greenhouse gas concentrations. Accounting for 5% of all global greenhouse gas emissions (this being a conservative estimation!), the tourism industry is not guilt-free.

Figure 1. The current levels of the control variables for 7 planetary boundaries. The planetary boundary falls at the end of the green zone. Grey is used where boundaries cannot yet be calculated for a process. Source.

The authors argue that if anthropogenic activities continue to shift the Earth's system out of Holocene conditions, this will likely culminate in an Earth-state that is much less catering to human societies. These boundaries and have been criticised for their subjectivity (although this is controversial and highly debated!), but the authors argue that controlling our activities so we stay within them would greatly reduce the risk of driving the Earth system into this dreaded unhospitable state. Through this blog, I would argue that tourism and travel directly contribute to this path on a global scale through, for example, greenhouse gas emissions from air travel. As such, application of these planetary boundaries is very relevant to management of the sector.

Furthermore, five of these processes, including freshwater use and biosphere integrity, have strong regional and local operating scales and thresholds, but aggregate at the global scale and feedback to the system processes with planetary-scale thresholds, such as climate change.

Figure 2. Framework illustrating the feedbacks between the local/regional impacts and global feedbacks, under the planetary scale framework. Figure displays the 3 zones and likely position of the threshold. Source.

This is especially important when considering the environmental impacts of tourism, as many of the industry’s impacts are exhibited in highly localised settings (i.e. Process Y), yet aggregate together or feedback to global-scale processes (i.e. Process X) to create global environmental problems. For example, localised damage to coral reefs at tourism-intense sites adds to the damage from other anthropogenic activities at many sites worldwide, and reduces resilience to global-scale processes including coral bleaching and climate change.

Ecosystem Services

The nine biophysical processes in the planetary boundaries framework maintain the Earth system’s stability through regulating biochemical flows (e.g. the biological carbon sinks) and by enhancing ecosystem resilience. Ecosystem resilience is linked to the second, distinct yet related, concept I wish to outline in this post – ecosystem services. Definitions of ecosystem services focus on the value and uses that ecosystems provide to humans, for example: “the benefits provided by the ecosystems that contribute to making human life both possible and worth living”.

In light of these human uses, the importance of ecosystem services to the tourism industry is vast. In particular, the category of ‘cultural services’ (Table 1), defined as “nonmaterial benefits people obtain from ecosystems through…recreation, and aesthetic experiences” is important in attracting tourists to a site in the first place. For example, the majority of tourism to the Great Barrier Reef in Australia is brought in by the attraction of the coral reefs ecosystems.

Figure 3. Categorised ecosystem services, and their interactions with human well being, and indirect or direct causes of change in ecosystem services. Interactions can occur at multiple spatial scales and can cross spatial scales. For example, a national demand for firewood can cause a regional loss of woodland, thus affecting the dynamics of a local river system. Interactions can also occur at multiple time-scales. Source.

As such, ecosystems have brought economic prosperity to humans. For the tourism industry, ecosystems in the forms of coral reefs, rainforests, alpine slopes and woodlands (to name a few!) have been critical in attracting tourists and generating income for areas, thus contributing to human well-being. Yet economic prosperity has led to overuse of provisioning services, resulting in over ½ of the world’s ecosystems having been lost in the past century, and the depletion of biodiversity having increased to an unprecedented rate (UN General Assembly, 2010). The overall diversity of services provided by degraded ecosystems is less, reducing the resilience of the ecosystem, and threatening the provisioning of ES in the long run. This blog will touch upon some of the ways tourism has contributed to decline of ecosystem services, through for example, the introduction of non-native invasive species and damage to coral reefs.

Last words...

I hope that this introductory post has provided you with an idea of the tourism-related environmental issues I shall be discussing in this blog, and some of the frameworks through which we can view and analyse them. Tune in next week for an overview of where research into tourism’s impact on the environment all began. ‘Till next time folks!