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Land-management options for greenhouse gas removal (GGR) include afforestation or reforestation (AR), wetland restoration, soil carbon sequestration (SCS), biochar, terrestrial enhanced weathering (TEW), and bioenergy with carbon capture and storage (BECCS). We assess the opportunities and risks associated with these options through the lens of their potential impacts on ecosystem services (Nature's Contributions to People; NCPs) and the United Nations Sustainable Development Goals (SDGs). We find that all land-based GGR options contribute positively to at least some NCPs and SDGs. Wetland restoration and SCS almost exclusively deliver positive impacts. A few GGR options, such as afforestation, BECCS, and biochar potentially impact negatively some NCPs and SDGs, particularly when implemented at scale, largely through competition for land. For those that present risks or are least understood, more research is required, and demonstration projects need to proceed with caution. For options that present low risks and provide cobenefits, implementation can proceed more rapidly following no-regrets principles.

Revision Notes "Eq. 4. I recommend to replace k with j. K could result in misunderstanding (it could be mixed up with a rate constant)" We totally agree with this comment of the reviewer. Therefore, it has been changed. L. 371-372 of the new version. Please present in a new table the mean temperature and rainfall for each sub-climate regions used in the study. We acknowledge the comment of the reviewer. We decided to not to include a table with values of temperature and precipitations due to the high complexity of the Köppen-Geiger climate classification. As it is shown in the figures below (Kottek et al., 2006), each climate is defined by three letters. Second letter corresponds to precipitations and the third one to the air temperature conditions. We considered that include all this information in a table would not be so much helpful to the paper and, for that reason we decided to include only the full name of each climate (e.g. Csa (Warm temperate, dry summer, hot summer)) and referring the table to this paper of Kottek et al., 2006. Highlights  Effects of RMPs on SOC in woody crops were assessed using literature data  Average SOC sequestration rate for all RMPs was 3.8 t C ha-1 yr-1.  C sequestration rates in olive orchard ranged 1.1 (CC) to 5.3 (OA) t C ha-1 yr-1.  C sequestration rate in vineyards was 0.78 t C ha-1 yr-1 in CC management.  C sequestration rates were highest during the first years of the RMPs *Highlights (for review)

This study evaluates the dynamics of soil organic carbon (SOC) under perennial crops across the globe. It quantifies the effect of change from annual to perennial crops and the subsequent temporal changes in SOC stocks during the perennial crop cycle. It also presents an empirical model to estimate changes in the SOC content under crops as a function of time, land use, and site characteristics. We used a harmonized global dataset containing paired‐comparison empirical values of SOC and different types of perennial crops (perennial grasses, palms, and woody plants) with different end uses: bioenergy, food, other bio‐products, and short rotation coppice. Salient outcomes include: a 20‐year period encompassing a change from annual to perennial crops led to an average 20% increase in SOC at 0–30 cm (6.0 ± 4.6 Mg/ha gain) and a total 10% increase over the 0–100 cm soil profile (5.7 ± 10.9 Mg/ha). A change from natural pasture to perennial crop decreased SOC stocks by 1% over 0–30 cm (−2.5 ± 4.2 Mg/ha) and 10% over 0–100 cm (−13.6 ± 8.9 Mg/ha). The effect of a land use change from forest to perennial crops did not show significant impacts, probably due to the limited number of plots; but the data indicated that while a 2% increase in SOC was observed at 0–30 cm (16.81 ± 55.1 Mg/ha), a decrease in 24% was observed at 30–100 cm (−40.1 ± 16.8 Mg/ha). Perennial crops generally accumulate SOC through time, especially woody crops; and temperature was the main driver explaining differences in SOC dynamics, followed by crop age, soil bulk density, clay content, and depth. We present empirical evidence showing that the FAO perennialization strategy is reasonable, underscoring the role of perennial crops as a useful component of climate change mitigation strategies.