Climate Change Mitigation and Adaptation

Conservation biology used to be a relatively isolated political field motivated mainly by ethical or even religious obligations to protect nature. In the past 10 years, a more anthropocentric perspective has advanced where biodiversity is not only appreciated for its inherent value but also for the services that are provided to human society. From this perspective, biodiversity conservation is indispensable for the provision of ecosystem services that humanity is depending on, such as the production of food or the filtration of water.¹⁴⁷¹ Another development has been the consideration of the interconnections between climate change and biodiversity. It has been realized by both, the biodiversity conservation as well as the climate change community, that synergies as well as conflicts between both policy fields exist that need to be dealt with.^148-511 There are two categories, mitigation and adaptation, that conceptualize how nature conservation can contribute to the management of climate change impacts. While mitigation corresponds to actions undertaken to alleviate future climate change, adaptation measures are aiming at enabling biodiversity to persist under climate change. Mitigation approaches mainly refer to strategies targeting the reduction of greenhouse gases in the atmosphere through either the minimization of emissions, e.g., the protection of carbon sources, or the maximization of greenhouse gas uptake, e.g., the protection or restoration of carbon sinks. On the other hand, adaptation measurements assume that at least some intensity of climate change will take place and that biodiversity can only be protected effectively if adaptive strategies are employed. Despite the straightforward definition of mitigation and adaptation, both are often not isolated but interconnected. In many cases, adaptation measures are only applicable if climate change is not exceeding critical thresholds and, vice versa, ecosystems are more likely to contribute effectively to climate change mitigation if they are in a healthy condition.

During the last few years, a new concept has become increasingly important, namely, ecosystem- based adaptation and mitigation.^152,531 Ecosystem-based adaptation refers to the utilization and strengthening of natural functions of ecosystems to make societies less vulnerable to the negative impacts of climate change. One example for ecosystem-based adaptation would be the abandonment of alluvial areas for construction in order to maintain space for flood protection, but other examples also exist where natural solutions can provide more effective and efficient options than technological advances for adaptation to climate change. Ecosystem-based mitigation follows the same approach but with the aim of increasing the capacity of ecosystems to store and capture carbon, e.g., through the conservation of natural carbon sinks and sources. Ecological engineering, on the other hand, focuses on actions coupling both technological and ecological solutions to benefit society.¹⁵⁴¹ These often relate to the restoration or enhancement of natural ecosystem functions or the use of these functions within technological solutions. One of the reasons that these two concepts, ecosystem-based actions and ecological engineering, have gained in relevance is their potential to explicitly combine aspects of climate change policy with biodiversity conservation. Table 3.3 gives examples for mitigation and adaptation strategies for all three options. While nature conservation and climate change policy have often

Biodiversity: Climate Change

TABLE 3.3 Examples for Strategies Aiming at the Mitigation of Climate Change and Adaptation toward Its Impacts

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acted independently from each other, it has been realized that collaborative approaches often provide synergies and beneficial effects for both policy areas. Furthermore, it turned out that pure technological solutions aiming at the mitigation and adaptation to climate change often entail substantial costs and efforts. Ecosystem-based actions and ecological engineering have the potential to provide cost-effective strategies to cope with future climate change.