INTERNATIONAL INSTITUTE OF TROPICAL AGRICULTURE (IITA)
Call for Expression of Interest (EOI): Recruitment of an Individual Consultant:
Research Analyst – Soil Carbon Meta-Analysis
CGIAR Climate Action Science Programme (CSAP)| Carbon Corridors (AOW4)
1. Background
The Carbon Corridors Initiative is undertaking a meta-analysis of empirical evidence on regenerative agriculture and soil organic carbon (SOC) sequestration across African agroecosystems. This research aims to synthesise fragmented evidence from across the continent to generate robust, context-specific estimates of soil carbon sequestration potential, and to translate these findings into actionable insights for agriculture-based carbon credit methodologies.
Despite growing interest in regenerative agriculture as a climate mitigation strategy, the African evidence base remains dispersed and largely site-specific. Existing carbon market methodologies require credible, Africa-grounded sequestration benchmarks. This study seeks to bridge the gap between soil carbon science, regenerative agriculture practice, and emerging voluntary carbon finance mechanisms, with direct relevance to smallholder farming systems across East and sub-Saharan Africa.
A critical component of this work is establishing robust baseline carbon assessments and evaluating carbon stock changes over time. Baseline carbon data, capturing current stocks of soil organic carbon (SOC) and, where applicable, above- and below-ground biomass, are foundational to any credible carbon project: they define the reference point against which sequestration gains are measured, and they underpin the calculation of carbon credits. Across much of Africa, such baselines are either absent, methodologically inconsistent, or not reported in ways compatible with carbon market standards, presenting a significant evidence gap that this consultancy will help to address.
2. Objective of the Consultancy
The consultant will provide specialist research and analytical support to deliver a rigorous, peer-review-quality meta-analysis on regenerative agriculture and SOC sequestration in Africa. A central focus will be placed on baseline carbon assessment methodology, both reviewing how baselines have been established in existing African studies and generating evidence to guide future, standardised baseline measurement approaches. The assignment supports both scientific and policy-facing outputs that will inform the design of credible soil carbon projects for African agricultural landscapes.
3. Scope of Work
The consultant will be responsible for the following tasks:
3.1 Systematic Literature Review
• Design and execute a systematic search strategy across Web of Science, Scopus, PubMed, Google Scholar, and AGRIS
• Screen records using PRISMA guidelines and maintain a transparent documentation trail
• Source grey literature from CGIAR centres (IITA, CIMMYT, ICRAF), FAO, and development partners (GIZ, USAID)
• Manage all references in Zotero and prepare a PRISMA flow diagram
3.2 Baseline Carbon Assessment Review
• Document baseline carbon assessment methodologies used across reviewed studies, including sampling design, depth increments, bulk density measurement, and conversion to carbon stocks
• Evaluate the consistency and comparability of baseline SOC measurements, identifying methodological gaps and sources of uncertainty
• Review how studies account for spatial variability in baseline carbon stocks across soil types, land use histories, and climate zones
• Assess the availability and quality of above-ground and below-ground biomass carbon data (where reported) alongside SOC baselines, with particular attention to agroforestry and restoration contexts
• Identify studies that include repeated carbon measurements over time, enabling assessment of carbon stock changes relative to an established baseline
• Draw on field-based experience in baseline carbon assessment (e.g., Afromontane restoration contexts) to critically evaluate reported methodologies and flag inconsistencies
3.3 Data Extraction & Database Development
• Extract key variables from eligible studies: study design, location, climate zone, soil type, regenerative practice type, SOC stocks, sampling depth, and bulk density
• Record baseline carbon values and assessment methodology as dedicated fields in the structured database
• Standardize and convert SOC measurements into annual sequestration rates (tC ha⁻¹ yr⁻¹ or tCO₂e ha⁻¹ yr⁻¹)
• Build and quality-check a structured, analysis-ready database
3.4 Meta-Analysis & Statistical Modelling
• Calculate effect sizes and apply random-effects models to estimate average SOC sequestration impacts relative to baseline conditions
• Conduct moderator analyses examining the influence of baseline SOC levels, practice type, study duration, soil texture, rainfall regime, and sampling depth
• Quantify uncertainty ranges associated with baseline carbon stock estimates and their influence on overall sequestration effect sizes
• Apply statistical software (R) to conduct analyses and visualise results
• Contribute analytical content to policy and methodological guidance documents
3.6 Reporting & Dissemination Support
• Prepare a technical synthesis report suitable for scientific publication
• Contribute to policy briefs for climate finance and sustainable food systems audiences
• Present findings at internal and external forums as required
4. Deliverables
1. Inception report: search strategy, inclusion/exclusion criteria, baseline assessment review framework, and work plan
Timeline: Month 1
2. PRISMA flow diagram and screened literature database (Zotero among other tools)
Timeline: Month 2
3. Structured data extraction database, including baseline carbon variables and assessment methodology fields.
Timeline: Month 3
4. Meta-analysis results: effect sizes, random-effects model outputs, moderator analyses (including baseline SOC as moderator)
Timeline: Month 4-5
5. Final technical report, baseline methodology guidance note, and policy brief; presentation of findings.
Timeline: Month 6
Nairobi, Nairobi County, Kenya On-site Contract