Nature-based solutions for climate change adaptation are not located where they are most needed across the Alps

Abstract

Climate change impacts mountains socio-ecosystems by increasing certain natural disasters and changing Nature's Contributions to People (NCP). Nature-based Solutions (NbS) are increasingly implemented to help local communities adapt to climatic hazards. However, the relevance of their location in relation to those hazards and local NCP has hardly been addressed. In the PORTAL project (Pathways of Transformation in the Alps), we identified and mapped a portfolio of 97 NbS for climate change adaptation in the European Alps. Most NbS addressed drought or soil instability, and aimed to provide multiple NCP simultaneously such as wood production and protective function against landslides. We analysed whether NbS are located where they are the most needed, according to both current and future intensity of the hazards they aim to address and to supply-flow-demand indicators of the NCP they aim to provide. We found that the location of NbS is overall not related to current supply-flow-demand indicators of most NCP, nor to intensity of hazards. Nevertheless, NbS addressing droughts and floods are located in areas where these hazards are more intense, but do not match higher values for NCP indicators. Conversely, NbS aiming to produce wood and to provide protective function against landslides are located in areas with greater levels of these NCP, regardless of the intensity of hazards. These results suggest that hazards and NCP indicators are not the main drivers of NbS implementation. We argue that integrating local climate conditions and current NCP flows is needed to underpin a macro-regional strategy for planning NbS implementation.

Levers for transformative nature-based adaptation initiatives in the Alps

“…The three NbS types are new findings that complement previous classifications of NbS. While some scholars discriminated NbS according to climatic hazards, NCP co-benefits (25,26) or types of intervention (18,69), we found that different interventions, or NbS addressing different climatic hazards, can be implemented by similar decision-making contexts. In other words, different local contexts can achieve transformative adaptation to one climatic hazard.…”

“…Study limitations Our study focused on a small number of NbS implemented in the Alps. However, our sample captures the diversity of activities that have been identified to address drought, floods and soil erosion in this region (26,113). Our insights can support NbS amplification in other regions, as we identified common levers and barriers with studies from other socio-ecological systems worldwide (70,114).…”

“…We explored NbS implemented in the Alps through the PORTAL database of initiatives (https://portal.osug.fr/-EXPLORE-THE-INITIATIVES-). This database collects around one hundred initiatives that aim to adapt to climate change or to mitigate natural hazards (likely enhanced by climate change) by safeguarding or increasing benefits in terms of NCP and/or biodiversity (26). In order to obtain a comparable subset of NbS, we identified the three climatic hazards the most addressed through all the NbS of the PORTAL database, namely droughts, floods and soil erosion (26), and we selected the NbS that aim to adapt to them.…”

“…This database collects around one hundred initiatives that aim to adapt to climate change or to mitigate natural hazards (likely enhanced by climate change) by safeguarding or increasing benefits in terms of NCP and/or biodiversity (26). In order to obtain a comparable subset of NbS, we identified the three climatic hazards the most addressed through all the NbS of the PORTAL database, namely droughts, floods and soil erosion (26), and we selected the NbS that aim to adapt to them. They included reforestation of plots by planting local or exotic adapted species trees to reduced drought impact, to safeguard the protective function of forests against natural hazards, or to protect crops from heatwaves; natural regeneration of degraded forests to increase their resilience to natural disturbances; river restoration to reduce flood impacts; restoration of grasslands to reduce landslides; transdisciplinary network to co-produce and share knowledge on adaptation to climate change in forestry, agricultural or natural disaster management sectors; enabling-NbS programme for local stakeholders.…”

“…Transformative NbS are also understood as incentive measures to enhance farmers to safeguard Nature's Contribution to People (NCP) (23), co-producing knowledge networks to adapt management practices (24), and creating biosphere reserve to reduce deforestation trends (13). Despite the growing evidence of the abilities of NbS to address a wide range of issues and to simultaneously provide various NCP co-benefits (25)(26)(27), they are not widely implemented (8,22,28), and particularly not where they are most needed (26,29). Indeed, technical or biophysical parameters are often not the main barriers; rather, NbS implementation is shaped by the social-ecological decision-This manuscript is a preprint and has not been peer reviewed.…”