To better anticipate potential impacts of climate change, diverse information about the future is required, including climate, society and economy, and adaptation and mitigation. To address this need, a global RCP (Representative Concentration Pathways), SSP (Shared Socio-economic Pathways), and SPA (Shared climate Policy Assumptions) (RCP-SSP-SPA) scenario framework has been developed by the Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC-AR5). Application of this full global framework at sub-national scales introduces two key challenges: added complexity in capturing the multiple dimensions of change, and issues of scale. Perhaps for this reason, there are few such applications of this new framework. Here, we present an integrated multi-scale hybrid scenario approach that combines both expert-based and participatory methods. The framework has been developed and applied within the DECCMA1 project with the purpose of exploring migration and adaptation in three deltas across West Africa and South Asia: (i) the Volta delta (Ghana), (ii) the Mahanadi delta (India), and (iii) the Ganges-Brahmaputra-Meghna (GBM) delta (Bangladesh/India). Using a climate scenario that encompasses a wide range of impacts (RCP8.5) combined with three SSP-based socio-economic scenarios (SSP2, SSP3, SSP5), we generate highly divergent and challenging scenario contexts across multiple scales against which robustness of the human and natural systems within the deltas are tested. In addition, we consider four distinct adaptation policy trajectories: Minimum intervention, Economic capacity expansion, System efficiency enhancement, and System restructuring, which describe alternative future bundles of adaptation actions/measures under different socio-economic trajectories. The paper highlights the importance of multi-scale (combined top-down and bottom-up) and participatory (joint expert-stakeholder) scenario methods for addressing uncertainty in adaptation decision-making. The framework facilitates improved integrated assessments of the potential impacts and plausible adaptation policy choices (including migration) under uncertain future changing conditions. The concept, methods, and processes presented are transferable to other sub-national socio-ecological settings with multi-scale challenges.

Purpose of Review: South Asia is highly vulnerable to the impacts of climate change, owing to the high dependency on climate-sensitive livelihoods and recurrent extreme events. Consequently, an increasing number of households are adopting labour migration as a livelihood strategy to diversify incomes, spread risks, and meet aspirations. Under the Collaborative Adaptation Research Initiative in Africa and Asia (CARIAA) initiative, four research consortia have investigated migration patterns and their inherent linkages to adaptation to climate change in climate hotspots. This article synthesizes key findings in regional context of South Asia. Recent Findings: The synthesis suggests that in climate-sensitive hotspots, migration is an important livelihood diversification strategy and a response to various risks, including climate change. Typically, one or more household members, often young men, migrated internally or internationally to work in predominantly informal sectors. Remittances helped spatially diversify household income, spread risks, and insure against external stressors. The outcomes of migration are often influenced by who moves, where to, and what capacities they possess. Summary: Migration was found to help improve household adaptive capacity, albeit in a limited capacity. Migration was mainly used as a response to risk and uncertainty, but with potential to have positive adaptation co-benefits.

Article 7, paragraph 14 of the Paris Agreement to the United Nations Framework Convention on Climate Change commits Parties to create a five yearly assessment of observed adaptation to track progress and enable appropriate future commitments through the Nationally Determined Contributions and National Adaptation Plans. No large‐scale study exists that shows the types of adaptation, the spatial distribution of types of adaptation, and the numbers of people engaging in that adaptation. To address this gap, and to feed into debates about the modalities for the global stocktake, in this paper we propose a new “stocktaking” approach to document the spectrum and prevalence of observed adaptation over large scales. The four‐step stocktaking approach focuses on: (a) obtaining consensus on the objectives of adaptation; (b) agreeing the sources of evidence; (c) agreeing the search method; and (d) categorizing the adaptations. By focusing on documenting rather than evaluating adaptation, the simple approach avoids some of the adaptation heuristic traps. With guidance to countries on how to operationalize, this approach could improve the transparency of adaptation data collection and analysis, ensure comparability of findings across space and time, and inform the Adaptation Communications (Article 7.10)—a prerequisite to strengthening future ambition commitments within the Paris Agreement.This article is categorized under: Policy and Governance > International Policy Framework Vulnerability and Adaptation to Climate Change > Institutions for Adaptation

For farmers in rural Africa, climate change could significantly alter the natural environment, leading to a loss of income, food security and well-being; however, much remains unknown about the way a change in climate may affect a person's decision to migrate away from their home. Using a framework based on migration aspirations and capabilities, this paper examines how climate stresses (such as droughts that cause a long-term decline in harvests) and climate shocks (i.e. acute food shortages and sudden flooding) may affect migration decision-making in rural Malawi. Drawing on survey (n = 255), interview (n = 75) and focus group (n = 93) data from rural and urban dwellers, we find that climate stresses typically do not change rural dwellers’ aspiration to leave their homes, except for a small group of younger farmers from better-off households. However, these same stresses may erode human, financial and social capital, thus reducing migration capability. Data also reveal that acute shocks erode both the migration aspirations and capabilities of even the most dedicated would-be migrant. Drawing from these two findings, this paper concludes that climate change is likely to increase barriers to migration rather than increasing migration flows in countries like Malawi where the economy is still predominately rural.

Deltas are precarious environments experiencing significant biophysical, and socio-economic changes with the ebb and flow of seasons (including with floods and drought), with infrastructural developments (such as dikes and polders), with the movement of people, and as a result of climate and environmental variability and change. Decisions are being taken about the future of deltas and about the provision of adaptation investment to enable people and the environment to respond to the changing climate and related changes. The paper presents a framework to identify options for, and trade-offs between, long term adaptation strategies in deltas. Using a three step process, we: (1) identify current policy-led adaptations actions in deltas by conducting literature searches on current observable adaptations, potential transformational adaptations and government policy; (2) develop narratives of future adaptation policy directions that take into account investment cost of adaptation and the extent to which significant policy change/political effort is required; and (3) explore trade-offs that occur within each policy direction using a subjective weighting process developed during a collaborative expert workshop. We conclude that the process of developing policy directions for adaptation can assist policy makers in scoping the spectrum of options that exist, while enabling them to consider their own willingness to make significant policy changes within the delta and to initiate transformative change.

The use of scientific information about future weather and climate offers enormous potential for society to better manage the risks associated with climate variability and change. There has been significant investment in weather and climate services (WCS) over the past years; however, empirically based evidence of the socio-economic benefits of such services is very limited. Understanding and capturing the real benefits of WCS as they unfold on the ground are key to ensure continue investment in WCS as well as to enable adaptive management. In this paper, we conduct a review of the literature of WCS evaluations in South Asia. We systematically document and analyse empirical evidence as reported in the academic and grey literature to highlight (1) the scale and scope of WCS that have been evaluated in the region; (2) the methodological approaches that have been used to monitor and evaluate the benefits of WCS initiatives on the ground and (3) the socio-economic benefits of WCS categorised under a triple bottom line approach that takes into consideration economic, social and environmental benefits. The paper explores these findings and highlights key areas that warrant further discussion and research. These include a limited effort to systematically record and document the benefits of WCS and an over-emphasis on capturing evidence of short-term economic benefits at the expense of long-term economic benefits, as well as social and environmental benefits. We conclude this paper with a call for increased cooperation between meteorologists, economists and social researchers to develop empirical case studies of benefits and trade-offs as they occur on the ground.