Cultural models of and for urban sustainability: assessing beliefs about Green-Win Abstract Green-Win is the proposal where that government, society, and business can all reap benefits while at the same time playing a vital role in the transition to sustainable development and lower carbon futures. We argue that, while the Green-Win proposition is central to many state and expert models of sustainability transitions, as a construction, it belies more complex trade-offs and cognitive models of sustainability and societal transitions. Cultural models are cognitive representations shared by a community which provide both models of the world, which aid in interpreting what is in the world, how it works, what is possible (or not) and why, and models for the world, which suggest how to act in it to bring about desired outcomes (cf. Geertz 1973). We surveyed 225 respondents in Shanghai, China, Istanbul, Turkey, and Beirut, Lebanon to assess their basic beliefs about sustainability, specifically whether it is possible to implement concrete practices that realize environmental sustainability goals in conjunction with economic development—the Green-Win proposition. We found important similarities and differences among urban stakeholders’ cultural models of sustainable development. For example, Chinese and Lebanese respondents displayed a strong belief that economic growth and environmental sustainability are compatible, while Turkish respondents showed significant disagreement with this proposition. We argue that such basic notions about the possibility of Green-Win opportunities between environmental sustainability and economic development are important to understand in the context of mitigating and adapting to climate change in critical urban environments. Cultural models of and for green development may either enable or inhibit transformations in urban systems according to local conditions. Finally, we discuss the potential implications of cultural models’ research for targeting communications and engendering collaborations among diverse stakeholders in order to align perspectives and overcome barriers that may otherwise limit successful visioning, planning, and implementation for transformation towards sustainable development.

The contribution of technological diffusion to climate change mitigation: a network-based approach Abstract We propose a novel approach to quantify the contribution of technological diffusion to climate change mitigation. First, we use a parametric model of epidemic diffusion to estimate from micro-level data the determinants and the structure of the networks of diffusion for three key mitigation technologies: electro-mobility, renewable energy and agriculture. We then simulate the propagation of new technological vintages on these networks and quantify the reduction of emissions induced by the diffusion process using a tailored feedback centrality measure labelled “emission centrality”. Finally, we investigate how new forms of international collaboration such as climate clubs can contribute to mitigation by catalysing the adoption of new technologies. Our approach can be used directly to measure the contribution of technological diffusion to mitigation or indirectly by providing estimates of global technological diffusion to integrated assessment models.

Population responses of bird populations to climate change on two continents vary with species’ ecological traits but not with direction of change in climate suitability Abstract Climate change is a major global threat to biodiversity with widespread impacts on ecological communities. Evidence for beneficial impacts on populations is perceived to be stronger and more plentiful than that for negative impacts, but few studies have investigated this apparent disparity, or how ecological factors affect population responses to climatic change. We examined the strength of the relationship between species-specific regional population changes and climate suitability trends (CST), using 30-year datasets of population change for 525 breeding bird species in Europe and the USA. These data indicate a consistent positive relationship between population trend and CST across the two continents. Importantly, we found no evidence that this positive relationship differs between species expected to be negatively and positively impacted across the entire taxonomic group, suggesting that climate change is causing equally strong, quantifiable population increases and declines. Species’ responses to changing climatic suitability varied with ecological traits, however, particularly breeding habitat preference and body mass. Species associated with inland wetlands responded most strongly and consistently to recent climatic change. In Europe, smaller species also appeared to respond more strongly, whilst the relationship with body mass was less clear-cut for North American birds. Overall, our results identify the role of certain traits in modulating responses to climate change and emphasise the importance of long-term data on abundance for detecting large-scale species’ responses to environmental changes.

National-scale analysis of future river flow and soil moisture droughts: potential changes in drought characteristics Abstract The potential impact of climate change on drought is of increasing concern, especially due to recent occurrences of major events across the globe. Here a national-scale grid–based hydrological model is used to investigate potential future changes in river flow and soil moisture droughts across Great Britain. The analysis uses ensembles of climate model data for four time periods (1930s, 1980s, 2030s and 2080s) under a “business-as-usual” (RCP8.5) emissions trajectory. The results show that the severity of droughts is projected to increase in the future. River flow droughts in southeastern regions are projected to increase in peak intensity and lengthen slightly, whereas peak intensities are projected to decrease for much of the rest of Britain. Droughts with the largest spatial extent across Britain are projected to increase in area for both river flow and soil moisture. More extreme droughts than previously experienced could have a significant impact on the aquatic environment as well as the availability of water for industry, agriculture and public water supply. Regional- to national-scale droughts could have implications for potential mitigation measures such as water transfer between regions. In turn, this could lead to social and economic impacts, especially as there are also likely to be future increases in demand.

Impact of internal variability on climate change for the upcoming decades: analysis of the CanESM2-LE and CESM-LE large ensembles Abstract The pace of climate change can have a direct impact on the efforts required to adapt. For short timescales, however, this pace can be masked by internal variability (IV). Over a few decades, this can cause climate change effects to exceed what would be expected from the greenhouse gas (GHG) emissions alone or, to the contrary, cause slowdowns or even hiatuses. This phenomenon is difficult to explore using ensembles such as CMIP5, which are composed of multiple climate models and thus combine both IV and inter-model differences. This study instead uses CanESM2-LE and CESM-LE, two state-of-the-art large ensembles (LE) that comprise multiple realizations from a single climate model and a single GHG emission scenario, to quantify the relationship between IV and climate change over the next decades in Canada and the USA. The mean annual temperature and the 3-day maximum and minimum temperatures are assessed. Results indicate that under the RCP8.5, temperatures within most of the individual large ensemble members will increase in a roughly linear manner between 2021 and 2060. However, members of the large ensembles in which a slowdown of warming is found during the 2021–2040 period are two to five times more likely to experience a period of very fast warming in the following decades. The opposite scenario, where the changes expected by 2050 would occur early because of IV, remains fairly uncommon for the mean annual temperature, but occurs in 5 to 15% of the large ensemble members for the temperature extremes.

An intra-household analysis of farmers’ perceptions of and adaptation to climate change impacts: empirical evidence from drought prone zones of Bangladesh Abstract The agricultural sector is highly vulnerable to climate change, particularly in drought-prone environments. An understanding of perceptions, adaptation strategies, and their determinants including a gender analysis can benefit vulnerable farmers and policy makers. Using a survey of 360 farming household heads and their spouses, this study identified the intra-household perceptions and their determinants, the major strategies adopted by the farmers to adapt to climate change, and the factors that affect their adaptation decision and choice of strategies including the role of intra-household decision making in a drought prone environment of Bangladesh. The adaptation methods identified include short-duration and drought-tolerant rice varieties, supplementary irrigation for crop production, non-rice winter and horticultural crops, and improved channels for irrigation and water harvesting. Discrete choice model results indicate that age, household size, membership in any organization, access to credit, drought severity, amount of cultivated land, and agricultural subsidy significantly influence farmers’ adaptation decision and choices. Results reveal that climate change perceptions of husbands and spouses within the same households differ significantly and intra-household decision making plays a significant role in adaptation decision and selection of alternative adaptation strategies. The results would improve our understanding of farms and farming households and their climate change perceptions and adaptation choices by location and gender, thereby enabling us to outline better strategies to adapt to the changing climate. Graphical abstract

Adaptive capacity in urban areas of developing countries Abstract Urban areas of developing countries face increasing risks due to climate change. This paper systematically identifies and examines research published between 2000 and 2017 that assesses urban adaptive capacity to climate change in developing countries. To critically examine this literature, we developed a conceptual framework of urban adaptive capacity. The framework focuses on key components of urban adaptive capacity in three dimensions: the characterization of adaptive capacity, the external factors mediating adaptive capacity, and the dynamics of adaptive capacity. The study sheds light on the spatial and scalar interactions of individuals, communities, and authorities’ adaptive capacities within urban areas and highlights the importance of governance and social institutions in shaping urban adaptive capacity. The work also finds shortcomings in the current assessment of urban adaptive capacity, with key gaps including a narrow focus on the range and types of adaptive capacity; limited assessment of the multilevel determinants, place-based processes, and urban determinants that shape adaptive capacity; and a lack of consideration of adaptive capacity interactions between social entities and with regard to climate sensitivity and exposure of a given area, including the potential for maladaptation. Addressing these research gaps would contribute to generate knowledge that can adequately support adaptation planning of urban areas in developing countries.

Streamflow response to climate change in the Greater Horn of Africa Abstract The Greater Horn of Africa region increasingly experiences high risk of water scarcity. A combination of frequent droughts, rapid population growth and rising urbanisation has reduced streamflow and intensified water abstraction, causing water and food shortages. Estimates of future streamflow changes in the region have so far been highly uncertain and evaluations using ground-based measurements are still limited. Here, future streamflow changes are estimated using a distributed hydrological model forced with an ensemble of high-resolution climate simulations produced using the European community Earth-System Model v3.1. The simulated streamflow is evaluated using observed data from 29 stations from river basins across different climate zones in the region. Evaluation results show large sub-regional variations in the performance of simulated streamflow. The sign and magnitude of future streamflow changes vary between climate simulations and river basins, highlighting the uncertainties in the hydrologic projections. Overall, the streamflow projections indicate large (seasonal, long-term mean and extreme) streamflow decreases for all major rivers in Ethiopia and increases in the equatorial parts of the region at the end of the century. The ensemble mean shows a 10 to 25% decrease in the long-term mean flow in Ethiopia and a 10% increase in the equatorial part of the region in 2080s. Similarly, there is a substantial change in high flows in 2080s, with up to − 50% reduction in the northern and 50% increase in the equatorial parts of the region. These findings are critical because the rivers provide water supply to a rapidly changing socio-economy of the region.

The road traveled and pathways forward: A review of Loss and Damage from Climate Change: Concepts, Methods and Policy Options by Mechler, R., Bouwer, L., Schinko, T., Surminski, S. & Linnerooth-Bayer, J. (Eds.)

A policy mixes approach to conceptualizing and measuring climate change adaptation policy Abstract Comparative research on climate change adaptation policy struggles with robust conceptualization and measurement of adaptation policy. Using a policy mixes approach to address this challenge, we characterize adaptation policy based on a general model of how governments govern issues of societal interest. We argue that this approach allows for context-sensitive measurement of adaptation policy, while being both comparable and parsimonious. This approach is tested in a study of adaptation policies adopted by 125 local governments located in Canada, France, Germany, the Netherlands, and the UK. Using a systematic data collection protocol, a total of 3328 adaptation policies were identified from local council archives between the periods of January 2010 and May 2017. Results of this analysis suggest that there is structured variation emerging in how local governments govern climate change adaptation, which justifies calls for comparative adaptation research to use measurements that capture the totality of adaptation policies being adopted by governments rather than focusing on specific types of adaptation policy. We conclude with a discussion of key issues for further developing of this approach.