The trilemma of land use 2.2
2.1.3 Land Degradation Neutrality as a goal of international sustainability policy The fight against land degradation and the issue of sustainable land stewardship are an integral part of the UNCCD in particular. With the inclusion of the goal of Land Degradation Neutrality (LDN) in the list of SDGs, the target of achieving a “land degradation-neutral world” by 2030 was agreed in 2015 (SDG 15 and 15.3). This goal is about offsetting land degradation caused by economic development in a different location (e.g. by ecosystem restoration), so that overall no further degradation takes place and the net effect in terms of land degradation is zero (Wunder et al., 2018b). Land degradation neutrality “is a state whereby the amount and quality of land resources necessary to support ecosystem functions and services and enhance food security remain stable or increase within specified temporal and spatial scales and ecosystems” (UNCCD, 2015). The goals of land degradation neutrality are (Cherlet et al., 2018:237) > to maintain or improve ecosystem services; > to maintain or improve land productivity in order to enhance food security; > to increase the resilience of terrestrial ecosystems, for example against natural disasters; > to search for synergies with other environmental objectives; > to strengthen good governance of land tenure. These goals are also set out in the UNCCD Strategic Framework 2018-2030 (UNCCD, 2017a). In summary, the protection, sustainable use and restoration of terrestrial ecosystems are a prerequisite for protecting biodiversity and the climate and for establishing a sustainable food system. The pressure to act is greater in the Anthropocene than ever before in the history of humankind.
2.2 The trilemma of land use In its analyses on land stewardship, the WBGU focuses on three global crises: the climate crisis (Section 2.2.1), the food-system crisis (Section 2.2.2) and the biodiversity crisis (Section 2.2.3). The current destruction, degradation and fragmentation of terrestrial ecosystems is accelerating anthropogenic climate change, driving biodiversity loss and impairing food security. All three crises, each in its own way, are related to the use of land or terrestrial biomass and, in turn, have an impact on global land use and terrestrial ecosystems. Attempts to mitigate these crises can further increase the pressure
on the land and increase competition: ‘negative emissions’, i.e. measures for the removal of CO2 from the atmosphere, which are increasingly being discussed in the context of climate-change mitigation, add another new and potent ‘customer’ for the services of terrestrial ecosystems and land. The conservation of biodiversity is not possible without an expanded and upgraded system of protected areas, comprehensive ecosystem restoration and the sustainable use of cultivated areas. Right up to today, the task of feeding a growing world population has been accompanied by a continuous increase in land-intensive dietary habits. As a result, there are warnings against growing global competition for land use (Smith, 2018). In the present report, the WBGU refers to the potential competition between these three dimensions as the ‘trilemma of land use’ (Figure 2.2‑1). Further demand – e.g. for space for housing and roads or from the bioeconomy – intensifies this competition. The WBGU has chosen the term ‘trilemma’ because it initially looks as if each of these crises can only be overcome at the expense of the other two. For example, in many cases it seems we have to make a choice: expand agricultural land or expand protected areas; produce animal feed or create carbon reservoirs; protect near-natural areas or increase the use of biomass. Finding solutions here will be a determining factor for sustainable land stewardship. The global land surface is limited, as is the amount of biomass that can be produced by the ecosystems. Humans currently use about a quarter of potential terrestrial net primary production for their needs such as food, feeds, fibre, wood and energy (IPCC, 2019b:5; Krausmann et al., 2013). An unlimited expansion of use is obviously not possible, so it must be a matter of reconciling and, where necessary, prioritizing the different increasing claims. This also means that the drivers of these claims on use must be taken into account to reveal ways of reducing uses. The following sections initially examine the three crises and their systemic linkages, before a positive vision for land stewardship is developed in Section 2.3.
2.2.1 The climate crisis Anthropogenic climate change continues unabated despite the political agreement reached in Paris in 2015. The last decade was the warmest decade on record and 2015 to 2019 were the five warmest years since records began. The global average increase in temperature since the beginning of industrialization is currently 1.1°C (WMO, 2019). The Intergovernmental
21