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Land use is at the core of various sustainable development goals. Long-term climate foresight studies have structured their recent analyses around five socio-economic pathways (SSPs), with consistent storylines of future macroeconomic and societal developments; however, model quantification of these scenarios shows substantial heterogeneity in land-use projections. Here we build on a recently developed sensitivity approach to identify how future land use depends on six distinct socio-economic drivers (population, wealth, consumption preferences, agricultural productivity, land-use regulation, and trade) and their interactions. Spread across models arises mostly from diverging sensitivities to long-term drivers and from various representations of land-use regulation and trade, calling for reconciliation efforts and more empirical research. Most influential determinants for future cropland and pasture extent are population and agricultural efficiency. Furthermore, land-use regulation and consumption changes can play a key role in reducing both land use and food-security risks, and need to be central elements in sustainable development strategies. There lacks model comparison of global land use change projections. Here the authors explored how different long-term drivers determine land use and food availability projections and they showed that the key determinants population growth and improvements in agricultural efficiency.

Food insecurity can be directly exacerbated by climate change due to crop-production-related impacts of warmer and drier conditions that are expected in important agricultural regions1–3. However, efforts to mitigate climate change through comprehensive, economy-wide GHG emissions reductions may also negatively affect food security, due to indirect impacts on prices and supplies of key agricultural commodities4–6. Here we conduct a multiple model assessment on the combined effects of climate change and climate mitigation efforts on agricultural commodity prices, dietary energy availability and the population at risk of hunger. A robust finding is that by 2050, stringent climate mitigation policy, if implemented evenly across all sectors and regions, would have a greater negative impact on global hunger and food consumption than the direct impacts of climate change. The negative impacts would be most prevalent in vulnerable, low-income regions such as sub-Saharan Africa and South Asia, where food security problems are already acute.

Previous studies have combined climate, crop and economic models to examine the impact of climate change on agricultural production and food security, but results have varied widely due to differences in models, scenarios and input data. Recent work has examined (and narrowed) these differences through systematic model intercomparison using a high-emissions pathway to highlight the differences. This paper extends that analysis to explore a range of plausible socioeconomic scenarios and emission pathways. Results from multiple climate and economic models are combined to examine the global and regional impacts of climate change on agricultural yields, area, production, consumption, prices and trade for coarse grains, rice, wheat, oilseeds and sugar crops to 2050. We find that climate impacts on global average yields, area, production and consumption are similar across shared socioeconomic pathways (SSP 1, 2 and 3, as we implement them based on population, income and productivity drivers), except when changes in trade policies are included. Impacts on trade and prices are higher for SSP 3 than SSP 2, and higher for SSP 2 than for SSP 1. Climate impacts for all variables are similar across low to moderate emissions pathways (RCP 4.5 and RCP 6.0), but increase for a higher emissions pathway (RCP 8.5). It is important to note that these global averages may hide regional variations. Projected reductions in agricultural yields due to climate change by 2050 are larger for some crops than those estimated for the past half century, but smaller than projected increases to 2050 due to rising demand and intrinsic productivity growth. Results illustrate the sensitivity of climate change impacts to differences in socioeconomic and emissions pathways. Yield impacts increase at high emissions levels and vary with changes in population, income and technology, but are reduced in all cases by endogenous changes in prices and other variables.

We study the effects of smallholder market participation on intra-household time allocation in Ethiopia. We followed 156 households for 2 consecutive days and recorded the time allocated to dairying, domestic chores, schooling, wage work and leisure. Propensity score matching was used to determine the average effect of household market participation on intra-household time allocation. Results show that market participant households spend significantly more time on dairying and non-dairying activities than non-participant households. There are also substantial gender differences in intra-household time allocation. Although men take up only a small part of the dairy activities, milk income shifts from women to men in participant households. Given that in participant households women spent substantially more time on domestic and dairying activities, it is important that time-saving technologies are introduced to reduce their workload in the household. Women’s participation in the formal milk market should also be strengthened to ensure their access to the milk income.

Provides insights regarding the possible procedures for assessing welfare, efficiency, and equity effects of value chain development (VCD) programs, taking advantage of available analytical tools derived from impact analysis, transaction cost theory, and contract choice approaches and briefly outlining the strengths and weaknesses of different measurement approaches for value chain appraisal based on empirical counterfactual analysis, dynamic value chain modeling, and systematic contract choice analysis of public-private partnerships. Three different—albeit complementary—approaches for evaluating VCD programs exist, focusing on (1) effectiveness in terms of net welfare effects, (2) efficiency through reduction of transaction costs, and (3) equity in contractual terms and distribution of risks for enforcing loyalty and trust. Each aspect requires a specific approach to guarantee the availability of relevant counterfactuals. Whereas effectiveness analysis can rely on empirical field data and common diff -in-diff procedures, efficiency analysis of transaction costs asks for a simulation modeling framework.