Science Task Force Paper Spotlight: Impact assessment frameworks for Nature-based Solutions for climate change

As the world embraces Nature-based Climate Solutions, such as reforestation, wetland restoration, and coastal defences, well-meaning projects sometimes cause unintended harm—such as displacing local biodiversity or negatively impacting ecosystems. In this paper, Orchard and colleagues review four leading assessment frameworks that guide environmental planning for carbon-based climate initiatives as well as tools used to analyse and approve projects like tree plantations and mangrove restoration, highlighting where they work and where they fall short.

The authors found that there exists a major inconsistency in protection levels, with some thoroughly assessing ecosystem services and identifying high-conservation areas, while others offer only minimal guidance. Similarly, many frameworks neglect the broader ecological effects of projects, like the impacts of sourcing materials or habitat displacement. In addition, frameworks vary in how they set comparison baselines. Some predict a “without-project” future, while others use a fixed-point baseline (e.g. comparing to current conditions).

The authors argue for assessment frameworks that emphasise measurable improvement over the current baseline, align with Nature-based Solutions and Nature-Positive goals, and allow for ongoing project adjustments. This is key to ensure better outcomes—robust assessments help ensure projects boost climate mitigation and biodiversity, mitigating potential downsides and integrating accountability from the start, since clear baselines and attention to indirect impacts strengthen reliability and support adaptive management.

The paper recommends the following: standardise ecological assessments to consistently include ecosystem services, indirect impacts, and high-priority conservation areas; embrace adaptive management, tracking outcomes against current baselines and adjusting actions over time; and integrate Nature-Positive principles into assessment tools to ensure projects deliver real ecological gains along with climate benefits.

To make climate projects that employ Nature-based Solutions truly sustainable, there is a need for assessment frameworks that are comprehensive, adaptive, and Nature-Positive—capturing the full ecological picture and guiding stronger, long-term benefits. This paper offers a valuable roadmap for improving project design and ensuring nature benefits as much as the climate.

Orchard, S., Fitzpatrick, B. M., Shah, M. A. R., & Andrade, A. (2025). Impact Assessment Frameworks for Nature-Based Climate Solutions: A Review of Contemporary Approaches. Sustainability, 17(2), 677. https://doi.org/10.3390/su17020677

This blog is part of a series developed by UN Decade on Ecosystem Restoration’s IUCN-led Science Task Force (STF). The blog series aims to highlight papers and resources relevant to the UN Decade and ecosystem restoration practitioners. Opinions expressed in these papers are those of the authors and do not necessarily reflect the opinions of IUCN or a consensus of its Member organisations.