This paper examines the relationship between income inequality and the adoption of climate mitigation policies in G20 countries between 1996 and 2020. Using a panel dataset on national climate polices and different measures of inequality, we estimate fixed-effects and correlated random-effects models to assess how inequality interplay with average income to influence climate policy adoption. The results indicate that both inequality and GDP per capita play a significant role, with their interaction revealing a non-linear effect: higher inequality tends to support policy adoption in lower-income countries, but reduces it in higher-income contexts. We identify a switching point in the average income level, beyond which inequality is associated with fewer climate policies. Further analysis of the income distribution shows that the share held by the bottom 10% of the population is positively related to policy adoption, whereas concentration at the top has a more mixed effect. These findings suggest that the distributional structure of income shapes the demand for, and political feasibility of, climate policies. The study highlights the importance of accounting for inequality when analysing the drivers of climate governance and provides evidence that economic growth alone does not ensure stronger climate action.

Growing climate change impacts call for increased efforts to adapt and to reduce its adverse consequences on society. Adaptation responses can themselves be a source of climate risk, generating negative environmental externalities while entailing budgetary costs for both governments and private citizens. A key example is the private use of air-conditioning for indoor air temperature regulation in the face of rising urban heat. In this paper, we empirically evaluate the impact of street green spaces (SGS) on residential electricity demand through their urban temperature regulation effect. We exploit a monthly panel of household metered electricity demand data from 129,524 households located in 2181 municipalities distributed across Italy, in the period between 2020 and 2022. We find evidence of a significant non-linear mediating role of SGS on the impact of temperature on household electricity demand. The most salient effect is a reduction in electricity consumption when hot temperatures occur - lowering monthly average electricity consumption by up to 11%-25% (for monthly maximum temperatures of 30 and 35 degrees C, respectively). The observed moderating effects of SGS are heterogeneous across municipalities, as they depend on contextual factors such as the degree of urbanization, baseline heat and SGS levels, and average income level. To dissipate across-municipality sorting concerns, we conduct propensity score weighting on a range of potentially confounding observables, and find our results remain consistent. We estimate that a policy increasing the average Green View Index (GVI) level across all municipalities to a value comparable to the median of the current distribution would reduce the growth in residential electricity consumption driven by climate change by more than two thirds (under Representative Concentration Pathway 8.5 climate conditions around 2050). This corresponds to a gross national-level private saving in energy bills of e150 million yearly in 2050. This is a noticeable benefit that represents about 7.3% of our estimated costs to implement such policy, and informs on a potentially substantial social and economic benefit of urban green spaces. Our results provide new quantitative evidence of the role of street green spaces for both energy demand reduction, and therefore climate change mitigation, and in terms of outdoor temperature reduction, supporting climate change adaptation.

Physiologically extreme heat increasingly threatens human health, particularly where climatic exposure intersects with systemic social, infrastructural and institutional unpreparedness. Systemic cooling poverty (SCP) describes conditions in which individuals are prevented from attaining thermal safety as a result of intersecting forms of systemic deprivation. Here we quantify SCP across 28 countries, mostly in the global south, by combining household survey data (n = 1,155,106 households), climate records and infrastructure datasets. We operationalize SCP through five dimensions-climate exposure, infrastructure and assets, social and thermal inequalities, health, and education and working standards-and construct an SCP index at subnational scale. SCP is widespread and unevenly distributed: almost 600 million people experience high levels of deprivation across SCP dimensions. Education, working standards and climate exposure are the most prevalent drivers. These results show that vulnerability to extreme heat arises from intersecting climatic and socio-institutional factors, highlighting the need for coordinated policies that address multiple dimensions of heat adaptation.

Climate change impacts are increasingly felt, and a key hazard for human health is exposure to chronic and acute heat. Air conditioning is an effective indoor adaptation technology. However, it is widely regarded as a form of “maladaptation” due to its high energy intensity and the detrimental impact it has on urban outdoor temperatures and global greenhouse gas emissions. On the other hand, urban green space (UGS) is widely regarded as an effective green infrastructure with potential to mitigate the urban heat island effect. In this context, here we built on a global validated model based on street-level vegetation density, satellite imagery, and ancillary covariates to track UGS in a large sample of cities worldwide (Falchetta and Hammad, forthcoming) and derive a context-aware but generalized statistical linkage with buildings electricity consumption statistics. Based on the modelled relations, we derive future projection of the potential contribution of UGS expansions to energy demand reduction in buildings in different regions of the world. Our study advances the quantitative, globally relevant understanding of the intersection between climate change adaptation and mitigation, and the role of nature-based solutions to reduce the feedback impacts of adaptation while providing ecosystem service co-benefits.

The use of renewable energy sources, the energy crisis, and the increased frequency and intensity of high-heat events are changing the conditions under which European households consume energy services for their thermal comfort. Leveraging high-frequency residential electricity consumption from more than 10,000 households in a municipality in northern Italy between 2021 and 2022, we show that solar photovoltaics (PV) adoption reduces grid electricity consumption, during high-price and high-temperature events, enhancing energy security and affordability. We evaluate the environmental benefits of PV adoption using the global estimates of the Social Cost of Carbon (SCC) to monetize the value of avoided negative externalities due to GHG emissions. The adoption of PV by an average household in Brescia saves up to 544 kg of CO2 in a year, leading to a reduction of environmental damage for a value of 166-266/year. Furthermore, based on our estimated demand functions, we measure significant differences in the loss of price-induced consumer surplus for households with and without PV, which amounts to between 133 and 300, respectively, highlighting substantial private benefits from PV adoption during price fluctuations. Our findings underscore the need for targeted policies that expand access to residential PV systems, not only to support climate goals but also to mitigate energy poverty by shielding vulnerable households from extreme fluctuations in electricity prices.

This paper provides the first global assessment of the energy implications of households' climate change adaptation through air-conditioning. We pool household survey data from 25 countries and employ a discrete-continuous choice econometric framework to simultaneously estimate the adoption and utilisation of air-conditioning. After identifying how individual drivers determine households' adaptation behaviours, we combine the estimated responses with socioeconomic, demographic, and, climate change scenarios available at a high spatial resolution to project future air-conditioning adoption and electricity demand, as well as the contribution of individual determinants. On average, we find that air-conditioning ownership increases households' electricity consumption by 37%, but the effect is highly heterogeneous, and it varies with weather conditions, income levels and across countries, revealing the importance of behaviors, practices, climate, and technologies. Compared to other socioeconomic, demographic, and climatic drivers of electricity demand, air-conditioning has the leading marginal effect, and it can account for a significant share of households' budget. We then show that, especially in developing and emerging countries, age, education, and urbanisation reinforce the positive, long-term effect of income and high temperatures on air-conditioning adoption and electricity demand for space cooling. The overall effect of socio-demographic, economic, and climatic drivers is a net increase in regional and global air-conditioning electricity by 2050. Electricity expenditure for air-conditioning is an important benchmark for tracking a new dimension of energy poverty related to the need of space cooling and our projections points at a new, emerging risk associated with this form of households' adaptation.

Heatwaves, which are escalating in frequency, duration and intensity, have prompted governments worldwide to issue vital health warnings to protect populations. These include urging individuals to stay cool, hydrated, avoid direct sun exposure and minimise strenuous activities. Regrettably, a significant segment of the population faces substantial challenges in accessing these crucial recommendations due to a range of issues termed "systemic cooling poverty". Systemic cooling poverty encompasses intricate layers of physical, social and intangible infrastructural deficiencies, impeding the provision of essential services necessary to ensure thermal safety during extreme heat episodes. Through an intersectional mixed-method examination, this study brings empirical evidence of the structural factors that exacerbate inequalities in attaining thermal safety among the African-Brazilian community, LGBTQI+ and disabled, living in two favelas in Rio de Janeiro. By shedding light on these lived experiences of cooling poverty, we contribute to the understanding of targeted interventions and policy measures that can alleviate the impacts of extreme heat and safeguard public health and well-being as temperatures rise.

The interplay of a warming climate and socio-demographic transformations will increase global heat exposure. Assessing future use and impacts of energy-intensive appliances for indoor thermal adaptation is therefore a crucial policy goal. Here we train statistical models on multi-country household survey data (n = 480,555) to generate global gridded projections of residential air-conditioning (AC) uptake and use. Our results indicate that the share of households owning AC could grow from 26% to a scenario median of 38% by 2050, implying a doubling of residential AC electricity consumption, to 925 TWh/yr. This growth will be highly unequal both within and across countries and income groups, with significant regressive impacts. Up to 4.5 billion heat-exposed people may lack AC access in 2050. Outcomes will largely depend on socio-economic development and climate change pathways. Our gridded projections can support the modelling of the impacts of residential AC on decarbonization pathways and health outcomes.

AbstractThe global population is aging at the same time as heat exposures are increasing due to climate change. Age structure, and its biological and socio-economic drivers, determine populations’ vulnerability to high temperatures. Here we combine age-stratified demographic projections with downscaled temperature projections to mid-century and find that chronic exposure to heat doubles across all warming scenarios. Moreover, >23% of the global population aged 69+ will inhabit climates whose 95th percentile of daily maximum temperature exceeds the critical threshold of 37.5 °C, compared with 14% today, exposing an additional 177–246 million older adults to dangerous acute heat. Effects are most severe in Asia and Africa, which also have the lowest adaptive capacity. Our results facilitate regional heat risk assessments and inform public health decision-making.

Climate change interacts with other environmental stressors and vulnerability factors. Some places and, owing to socioeconomic conditions, some people, are far more at risk. The data behind current assessments of the environment-wellbeing nexus is coarse and regionally aggregated, when considering multiple regions/groups; or, when granular, comes from ad hoc samples with few variables. To assess the impacts of climate change, we require data that are granular and comprehensive, both in the variables and population studied. We build a publicly accessible data set, the SHARE-ENV data set, which fulfills these criteria. We expand on EU representative, individual-level, longitudinal data (the SHARE survey), with environmental exposure information about temperature, radiation, precipitation, pollution, and flood events. We illustrate through four simplified multilevel linear regressions, cross-sectional and longitudinal, how full-fledged studies can use SHARE-ENV to contribute to the literature. Such studies would help assess climate impacts and estimate the effectiveness and fairness of several climate adaptation policies. Other surveys can be expanded with environmental information to unlock different research avenues.

Born out of a 5-year-long scientific research by the University of Venice, The Cooling Solution is a photographic project which investigates how people from different socioeconomic backgrounds adapt to rising temperatures and humidity. The project has been developed as an indoor and outdoor exhibition, a catalog, and a website. It points out inequalities linked to access to energy and cooling technologies in India, Indonesia, Brazil and Italy reflecting on the way cooling strategies, architecture and social habits affect our relationship to the increasing heat across the world. The project starts from scientific data and blends them with personal stories and portraits to return an immersive and engaging experience for the visitors. The successful exhibition held in Venice in 2023 resulted in a wide dissemination of the research outputs outside of the sphere European research projects usually reach, involving a broad, diverse and international audience. Key for the development of the project was the involvement of different skilled professionals, which added a crucial element to the mix. The coordination of work was assigned to a communication agency specialized in academic content, who guided the photographer in developing her reportages, but also developed a narrative which could hold together the dozens of scientific papers produced during the ERC project with the photography. The involvement of a professional curatorship then allowed to plan, layout and choose a subset of 67 pictures among the hundreds shot by the photographer, creating at last a multilayered narrative where all elements - texts, scientific data, photography - coexisted without prevailing on one another. While planning and implementing the exhibition, the human dimension has always remained prevalent, knowing that the possibility to resonate and link with people's thoughts and possibly behaviors can be mediated through personal emotions.

Sustainable water management is essential to increasing water availability and decreasing water pollution. The wastewater sector is expanding globally and beginning to incorporate technologies that recover nutrients from wastewater. Nutrient recovery increases energy consumption but may reduce the demand for nutrients from virgin sources. We estimate the increase in annual global energy consumption (1,100 million GJ) and greenhouse gas emissions (84 million t CO(2)e) for wastewater treatment in the year 2030 compared to today's levels to meet sustainable development goals. To capture these trends, integrated assessment and computable general equilibrium models that address the energy-water nexus must evolve. We reviewed 16 of these models to assess how well they capture wastewater treatment plant energy consumption and GHG emissions. Only three models include biogas production from the wastewater organic content. Four explicitly represent energy demand for wastewater treatment, and eight include explicit representation of wastewater treatment plant greenhouse gas emissions. Of those eight models, six models quantify methane emissions from treatment, five include representation of emissions of nitrous oxide, and two include representation of emissions of carbon dioxide. Our review concludes with proposals to improve these models to better capture the energy-water nexus associated with the evolving wastewater treatment sector.

Sustainable water management is essential to increase water availability and decrease pollution in surface and ground water. The expanding wastewater sector plays a pivotal and growing role in managing wastewater globally. Furthermore, technology in use at wastewater treatment plants is evolving to recover nutrients, which increases energy consumption. This technology, however, may reduce demand to produce nutrients from virgin sources. To capture these trends in the wastewater sector and its interlinkages with the fertilizer and agricultural sectors, it is essential for integrated assessment and computable general equilibrium models that address the energy-water nexus to evolve. We estimate how much energy consumption (1,100 million GJ) and greenhouse gas emissions (84 million t CO2e) may increase globally until 2030. We also estimate that the share of national fertilizer demand that could be recovered from wastewater could be nearly 100% for some African nations, but is much lower for large, agriculturally dominant nations like China and the United States. We then review sixteen models integrated assessment and computable general equilibrium models to assess how well they capture wastewater treatment plant energy consumption and GHG emissions. Only three models included biogas production from wastewater organic content. Four models explicitly included representations of energy demand for wastewater treatment, and eight models included explicit representation of the greenhouse gas emissions produced by wastewater treatment. Of the eight models including representation of greenhouse gas emissions from wastewater treatment, six models include representation of methane emissions from treatment, five models include representation of emissions of nitrous oxide, and two models include representation of emissions of carbon dioxide. Our review concludes with proposals to improve integrated assessment and computable general equilibrium models to better capture the energy-water nexus associated with the evolving wastewater treatment sector.

Background and Objectives The co-occurring trends of population aging and climate change mean that rising numbers of U.S. older adults are at risk of intensifying heat exposure. We estimate county-level variations in older populations' heat exposure in the early (1995-2014) and mid (2050) 21st century. We identify the extent to which rising exposures are attributable to climate change versus population aging. Research Design and Methods We estimate older adults' heat exposure in 3,109 counties in the 48 contiguous U.S. states. Analyses use NASA NEX Global Daily Downscaled Product (NEX-GDDP-CMIP6) climate data and county-level projections for the size and distribution of the U.S. age 69+ population. Results Population aging and rising temperatures are documented throughout the United States, with particular "hotspots" in the Deep South, Florida, and parts of the rural Midwest. Increases in heat exposure by 2050 will be especially steep in historically colder regions with large older populations in New England, the upper Midwest, and rural Mountain regions. Rising temperatures are driving exposure in historically colder regions, whereas population aging is driving exposure in historically warm southern regions. Discussion and Implications Interventions to address the impacts of temperature extremes on older adult well-being should consider the geographic distribution and drivers of this exposure. In historically cooler areas where climate change is driving exposures, investments in warning systems may be productive, whereas investments in health care and social services infrastructures are essential in historically hot regions where exposures are driven by population aging.

European policy makers are increasingly interested in higher spatial representations of future macro-economic consequences from climate-induced shifts in the energy demand. Indeed, EU sub-national level analyses are currently missing in the literature. In this paper, we conduct a macro-economic assessment of the climate change impacts on energy demand at the EU sub-national level by considering twelve types of energy demand impacts, which refer to three carriers (petroleum, gas, and electricity) and four sectors (agriculture, industry, services, and residential). These impacts have been estimated using climatic data at a high spatial resolution across nine Shared Socioeconomic Pathway (SSP) and Representative Concentration Pathway (RCP) combinations. The impacts feed into a Computable General Equilibrium model, whose regional coverage has been extended to the sub-national NUTS2 and NUTS1 level. Results show that negative macroeconomic effects are not negligible in regions located in Southern Europe mainly driven by increased energy demand for cooling. By 2070, we find negative effects larger than 1% of GDP, especially in SSP5-RCP8.5 and SSP3-RCP4.5 with a maximum of − 7.5% in Cyprus. Regarding regional differences, we identify economic patterns of winners and losers between Northern and Southern Europe. Contrasting scenario combinations, we find that mitigation reduces adverse macro-economic effects for Europe up to a factor of ten in 2070, from 0.4% GDP loss in SSP5-RCP8.5 to 0.04% in SSP2-RCP2.6.

# ggACene (global gridded Air Conditioning energy) projections This data repository hosts output data for SSPs126, 245, 370 and 585 on the estimated and future projected ownership of residential air conditioning, its energy consumption, and the underlying population (useful to quantify the per-capita average consumption or the headcount of people affected by the cooling gap). The repository also hosts input data to replicate the data generating process. A twin Github repository hosts code (https://github.com/giacfalk/ggACene) to run the model generating the ggACene (global gridded Air Conditioning energy) projections dataset. ## Running the model To reproduce the model and generate the dataset from scratch, please refer to the following steps: - Download input data by cloning the repository - Adjust the path folder in the sourcer.R script - Run the sourcer.R script to train the ML model and make projections ## References Falchetta, G., De Cian, E., Pavanello, F., & Wing, I. S. Inequalities in global residential cooling energy use to 2050 *Under review*

Temperature records are being broken across the world, leading to incalculable suffering. The poorest and most disadvantaged people, who contributed the least to global warming, are the ones bearing the most severe consequences of extreme heat because of their limited adaptive capacity. Understanding the needs of the most disadvantaged is imperative to develop fair and adequate strategies to adapt to extreme heat and keep cool. This Perspective discusses how to understand systemic cooling poverty with the aim of informing policy and practice to support vulnerable people. Heatwaves are more frequent and lead to considerable suffering, especially among the poorest and most disadvantaged people. This Perspective discusses the concept of systemic cooling poverty with the aim of informing policy and practice to support vulnerable groups.

In this work we investigate the response of daily electricity peak load to daily maximum temperatures across states in Europe and India. We propose a method that decomposes short-from medium/long-run effects, retains the high frequency nature of the load-weather covariation and treats economic growth as a modulating factor. By simultaneously exploiting variation in unexpected daily weather anomalies and decade-long climatic changes in each location we decompose transitory -intensive margin -adjustments from permanent -extensive margin -adjustments. We find that the shocks over the long-run differ substantially from the short-run dynamics. Furthermore, we find evidence that per capita income modulates the adjustments over the short -and long-run. We project that in response to climate change around 2050 the peak load may increase by up to 20%-30% in Southern Europe and in several states in India, depending on the degree of warming and the evolution of socio-economic conditions. Even with a limited scope to two world regions, we identify that the structure of the economy and differences in future income growth matter in shaping the adaptation to climate change. Our decomposition allows to identify how future weather anomalies can further amplify the relative increase associated to the shift in the climate norm. Assuming that the interannual variability of maximum temperatures follows the distribution observed in the past, we find a doubling of the impacts of climate change during the summer in Europe. Uncertainty around the distribution of future weather anomalies may lead to further unexpected peak load amplifications. Our results have important policy implications for power systems' generation capacity, transmission and storage, as we show that the challenges to accommodate the peak load in days with extreme temperatures may substantially increase already around mid-century.

This paper aims to provide insights on potential strategies for a sustainable energy transition amidst market fluctuations. We analyze the impact of PV adoption on electricity consumption during a volatile price time span, leveraging high-frequency consumption data of over 10,000 households in Northern Italy during the period of the 2022 energy crisis. Our findings reveal that PV adoption reduces electricity consumption responsiveness during extreme price and temperature events, enhancing energy security and affordability. Based on estimated demand, we measure changes in consumer surplus, highlighting substantial benefits from PV adoption: the change in the annual consumer surplus due to the 2022 price increase is around 300 euros for the median consumer with no PV and 133 euros when PV is adopted by a comparable median household.

The objective of this study is to analyze how inequality affects the demand for emission reduction policies. It is generally recognized that a more equal income distribution can improve environmental quality (IPCC, 2022) influencing several mechanisms, such as the value placed on environmental public goods, the influence of social norms or the cost-benefit distribution of environmental protection. However, the focus so far has been on outputs (i.e., pollution concentration), disregarding the fact that a major component in determining the impact on the environment is the demand for – and implementation of – policies, which are the tools to actually define emission caps or incentivize green technologies.To fill this gap, we explicitly focus on the relationship between inequality and environmental policies. Our leading research question is: how does the distribution of income affect the demand of emission reduction policies?Our analysis covers national mitigation-related policies implemented in G20 countries between 1997 and 2021. We use the Climate Policy Database (Nascimento et al., 2022) to create indicators of policy adoption. In line with the policy density approach, we use the count of mitigation policies adopted annually by each country as dependent variable, and consider it as an approximation of climate policy demand.To capture different aspects of income distribution, we adopt different inequality measures (WID, 2022). We consider the national income shares of specific parts of the population (Top 10%, Bottom 10%, Bottom 40%) as well as commonly used inequality indices (Gini index and Palma ratio). We also construct a composite index, which combines the Gini with the ratio of the income shares held by the top and bottom 10% (Sitthiyot & Holasut 2022). We interact our inequality indicators with GDP per capita (PPP), as we assume that the impact of inequality may differ according to the national income level.Given the count data nature of our dependent variable, our empirical strategy is based on a fixed-effects Poisson regression model. We control for several institutional and policy-relevant variables.Our results show that the impact of inequality on climate policy implementation depends on the country's average income level. While in wealthy countries a reduction of inequality leads to a lower number of mitigation policies, in poorer countries an increase in inequality may drive the adoption of new policies. At the same time, the effect of economic growth is also not straightforward: an increase in average income has a positive impact on policy adoption in low-inequality societies. Conversely, an average income increase has a negative impact on climate mitigation adoption in highly unequal societies.Our findings confirm that inequality plays a key role in the adoption of national mitigation policies. These results, which are robust across multiple specifications of inequality indicators, highlight the importance of advancing knowledge on how equity and environmental challenges interact in order to get full support and progress with the climate agenda. Our results aim to inform the current policy debate on potential trade-offs between climate and equity by presenting new evidence on the interconnections between social and environmental goals.