Because their assets and income represent such a small share of national wealth, the impacts of climate change on poor people, even if dramatic, will be largely invisible in aggregate economic statistics such as the Gross Domestic Product (GDP). Assessing and managing future impacts of climate change on poverty requires different metrics, and specific studies focusing on the vulnerability of poor people. This special issue provides a set of such studies, looking at the exposure and vulnerability of people living in poverty to shocks and stressors that are expected to increase in frequency or intensity due to climate change, such as floods, droughts, heat waves, and impacts on agricultural production and ecosystem services. This introduction summarizes their approach and findings, which support the idea that the link between poverty and climate vulnerability goes both ways: poverty is one major driver of people's vulnerability to climate-related shocks and stressors, and this vulnerability is keeping people in poverty. The paper concludes by identifying priorities for future research.

Our spatial analysis indicates that in 2000 over one third of the rural population in developing countries was located on less favored agricultural land and areas, which are constrained by biophysical conditions or poor market access. We examine whether these spatial distributions of rural population in 2000 influence subsequent changes in the rate of poverty from 2000 to 2012 in 83 developing countries. We find no evidence of a direct impact on changes in poverty, but there is a significant indirect impact via the elasticity of poverty reduction with respect to growth. If climate change leads to more people concentrated in these areas, or an increase in unfavorable agricultural regions, then the poverty-reducing impact of overall per capita income growth could be further weakened. Reducing poverty will require targeting rural populations in less favored lands and remote areas and encouraging out-migration.

We analyze links between exposure to climate extremes and shocks, vulnerability and coping strategies, environmental reliance and poverty among 7,300 households in forest adjacent communities in 24 developing countries. We combine observed income with predicted income to create four categories of households: income & asset poor (structurally poor), income rich & asset poor (stochastically non-poor), income poor & asset rich (stochastically poor) and income & asset rich (structurally non-poor), and assess exposure and vulnerability across these groups. The income poor are more exposed to extreme climate conditions. They tend to live in dryer (and hotter) villages in the dry forest zones, in wetter villages in the wet zones, and experience larger rainfall fluctuations. Among the income-generating coping strategies, extracting more environmental resources ranks second to seeking wage labor. The poorest in dry regions also experience the highest forest loss, undermining the opportunities to cope with future climate shocks.

Rural households in developing countries depend on crops, forest extraction and other income sources for their livelihoods, but these livelihood contributions are sensitive to climate change. Combining socioeconomic data from about 8,000 smallholder households across the tropics with gridded precipitation and temperature data, we find that households have the highest crop income at 21°C temperature and 2,000 mm precipitation. Forest incomes increase on both sides of this agricultural maximum. We further find indications that crop income declines in response to weather shocks while forest income increases, suggesting that households may cope by reallocating inputs from agriculture to forests. Forest production may thus be less sensitive than crop production to climatic fluctuations, gaining comparative advantage in extreme climates and under weather anomalies. This suggests that well-managed forests might help poor rural households to cope with and adapt to future climate change.

Despite complex interlinkages, insights into the multifaceted relationship between environmental risks and poverty can be gained through an analysis of different risks across space, time and scale within a single context using consistent methods. Combining geo-spatial data on eight environmental risks and household survey data from 2010–2014 for the case study of Vietnam, this paper shows: (i) at the district level, the incidence of poverty is higher in high risk areas, (ii) at the household level, poorer households face higher environmental risks, (iii) for some risks the relationship with household-level consumption varies between rural and urban areas, and (iv) environmental risks explain consumption differences between households, but less so changes over time. While altogether these analyses cannot establish a causal relationship between environmental risks and poverty, they do indicate that Vietnam's poor are disproportionally exposed. Given growing pressures due to climate change, addressing such risks should be a focus of poverty reduction efforts.

People living in poverty are particularly vulnerable to shocks, including those caused by natural disasters such as floods and droughts. This paper analyses household survey data and hydrological riverine flood and drought data for 52 countries to find out whether poor people are disproportionally exposed to floods and droughts, and how this exposure may change in a future climate. We find that poor people are often disproportionally exposed to droughts and floods, particularly in urban areas. This pattern does not change significantly under future climate scenarios, although the absolute number of people potentially exposed to floods or droughts can increase or decrease significantly, depending on the scenario and region. In particular, many countries in Africa show a disproportionally high exposure of poor people to floods and droughts. For these hotspots, implementing risk-sensitive land-use and development policies that protect poor people should be a priority.

Recent research documents the adverse causal impacts on health and productivity of extreme heat, which will worsen with climate change. In this paper, we assess the current distribution of heat exposure within countries, to explore possible distributional consequences of climate change through temperature. Combining survey data from 690,745 households across 52 countries with spatial data on climate, this paper suggests that the welfare impacts of added heat stress may be regressive within countries. We find: (1) a strong negative correlation between household wealth and warmer temperature in many hot countries; (2) a strong positive correlation between household wealth and warmer temperatures in many cold countries; and (3) that poorer individuals are more likely to work in occupations with greater exposure. While our analysis is descriptive rather than causal, our results suggest a larger vulnerability of poor people to heat extremes, and potentially significant distributional and poverty implications of climate change.

This paper builds a multi-generation household model of consumption, accumulation, and risk management to assess the dynamic consequences of climate risk exposure. The model incorporates long-term impacts of consumption shortfalls, induced by optimal ‘asset smoothing’ coping behavior of the vulnerable, on poverty. The analysis shows the long-term level and depth of poverty can be improved by incorporating ‘vulnerability-targeted social protection’ into a conventional social protection system. The paper further shows insurance-based vulnerability-targeted social protection dominates (in economic growth and poverty reduction measures) both in-kind transfers and asset-based vulnerability-targeted protection. We then stress test social protection mechanisms and find the relative performance of insurance-based vulnerability-targeted social protection improves when subjected to current pessimistic projections about increasing drought risk. However, if drought risk increases beyond current climate change projections, then even the vulnerability-targeted policy loses its ability to stabilize the extent and depth of poverty.