Global intervention scenarios reveal the need for integrated cross-sectoral transformations to address biodiversity and climate challenges

The interconnected nature of global challenges such as biodiversity loss and climate change requires moving from single-focus, siloed strategies to integrated approaches involving multiple actors, interventions and sectors to achieve sustainable outcomes. However, assessing the effectiveness, trade-offs and synergies of such integrated approaches is often difficult and requires significant time and resources. Global models can help to explore long-term, cross-sectoral impacts of various interventions that cannot be captured through isolated or short-term analyses. Consequently, they can be valuable tools to assess interventions related to different elements of the Nexus.

We compiled a database of model-based intervention scenarios (policy-screening and target-seeking) providing an overview of the interventions applied within the scenarios, targeted sectors and resulting impacts. Using this database, we identified current research gaps in the analysis of global-scale intervention scenarios. Furthermore, we performed a meta-analysis to identify interventions with the potential for a synergistic impact on climate and biodiversity.

Next to well-known single-focus interventions such as greenhouse gas emission markets or nature protection, addressing climate change or biodiversity loss respectively, we identified circular economy approaches, such as dietary changes or reduced food waste, as promising interventions with synergistic effects. However, global integrated scenarios envisioning multi-sectoral change towards a more sustainable world deliver the highest biodiversity outcomes and also benefit the climate. By contrast, scenarios that focus on fewer sectors, often climate-first approaches, improve climate outcomes, but can lead to trade-offs for biodiversity. A key instrument of the latter is carbon pricing, which could cause problems with public acceptance as prices increase. However, we found that implementing additional interventions could limit carbon prices, thereby reducing total carbon costs. This highlights the effectiveness of combining carbon pricing with other complementary measures to reduce potential trade-offs and maximize positive impacts.

Our meta-analytical approach enables us to emphasize the importance of integrated, cross-sectoral action. It also highlights additional interventions that can accompany well-known ones, helping us to achieve the most effective synergistic outcomes for a nature-positive world.