events require sufficiently long panels to track the effects of such gradual changes.

Lastly, considering the key role played by agriculture as the main income-generating activity for households living in rural areas, linking detailed information on agricultural output with high-resolution, crop- and areaspecific, growing-season climatic time series is required. In sum, when combined all together, the existing data gaps and needs represent one of the main obstacles that currently prevent further advancements in applied research.

# **3. Shedding light on the climate-migration nexus: An opportunity for innovation**

# **3.1 An empirically-oriented conceptual framework on the climate migration nexus**

An empirically-grounded conceptual framework on the climate-migration nexus, depicted in Figure 1, highlights data gaps that can be addressed through multi-topic household surveys. This framework draws inspiration from theoretical insights provided by the extensive literature on asset-based and shock-driven poverty traps (Barrett and Carter, 2013; Carter and Barrett, 2006; Carter et al., 2007 and 2008; Jalan and Ravallion, 2002; Letta et al., 2018) and incorporates the analysis of mobility patterns into the broader context of resilience and adaptation.

The framework starts by distinguishing migratory responses depending on the nature of the climatic event: slow-onset changes _vs._ fast-onset shocks. We include as slow-onset changes events such as desertification, progressive warming, droughts, and permanent changes in rainfall patterns.<sup>18</sup> Fast-onset events refers to devastating floods, torrential rains, hurricanes, cyclones, and storms. As discussed in subsection 2.2, this is a standard distinction in the literature (Cattaneo et al., 2019), which is rooted in the different nature of the climatic events: in the face of slow-onset changes and cumulative, repeated shocks, the outcome is typically either long-distance, (semi-)permanent migration or immobility, depending on how the shock interacts with the mediating channels and contextual factors. In the case of fast-onset shocks, which typically involve forced physical relocation from the place of living, the prevailing outcome is usually a type of migratory response which is temporary and over short distances (Letta et al., 2023). Given the strictly ‘involuntary’ aspect of movements triggered by sudden shocks, the mediating channels and contextual factors play a much more minor role in shaping the climate-migration relationship, as the displacement brought about by such shocks typically leaves less if any room for aspects such as _in situ_ adaptation or the decision to send a household member away to diversify risk (economically driven migration), regardless of household wealth, assets, and resources.

Unlike the response to fast-onset shocks which is intrinsically immediate, when there is a migratory response to slow-onset events, it tends to be a long-run response, in the form of gradually progressive migratory flows. These events are more likely to activate a range of alternative “adaptation” pathways, both on and off the farm.

> 18 We do not include sea-level rise among slow-onset changes because its impact on migration is expected to materialize only in the (very) long run (Duijndam et al., 2021). Also, the nature of sea-level rise related hazards that can unfold in the shorter term is mixed as they can comprise both more gradual changes such as soil and groundwater salinization or erosion as well as sudden occurrences such as flooding from storm surges (Duijndam et al., 2021), and these events are in fact covered in the conceptual framework.

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