Common prosperity is an essential requirement of socialism with Chinese characteristics for a new era. Problems caused by the urban rural dual structure, such as resource misallocation, ecological-economic imbalance, and insufficient farmer income growth, not only hinder common prosperity but also conflict with the sustainable development strategy. As the core path to break the dual structure and narrow gaps, the multi-dimensional impact and mechanism of urban rural integrated development on common prosperity need systematic verification. Based on panel data of 31 Chinese provinces from 2014 to 2023, this paper uses fixed-effects and mechanism test models to examine its direct, indirect, and spatial spillover effects, focusing on transmission mechanisms of wage, property, and operating incomes. Findings show: First, it exerts significant positive direct and cross-regional spillover effects on common prosperity; Second, wage and property incomes are key transmission paths, while operating income’s mediating effect is unclear; Third, effects vary geographically, stronger in eastern/central China, weaker in northeast China and insignificant in west China; Fourth, economic and spatial integration play prominent roles, social service integration has inhibitory effect, and ecological integration’s effect is under-released. Accordingly, this paper puts forward countermeasures to optimize resource allocation, tackle the rural operating income dilemma, advance regional coordination, and enhance equal social services, providing references for improving common prosperity policies and rural sustainable development.

Climate change poses a growing threat to global food security, with staple crop prices serving as a key transmission channel. This study systematically assesses the impacts of climate change on real maize price levels across 39 major producing countries over 1992–2023, using a two-way fixed-effects model with country-specific trends. Climate conditions are captured by growing-season mean temperature, accumulated precipitation, the share of extreme heat days (above 30 °C), and a drought indicator based on the Standardized Precipitation Evapotranspiration Index (SPEI). The benchmark results show a significant U-shaped relationship between growing-season temperature and maize price levels, with a turning point near 15.3 °C, implying that further warming raises prices in most producing countries. Extreme events emerge as the dominant driver: a one-standard-deviation increase in the share of extreme heat days is associated with approximately 11.9% (β = 0.610, p < 0.01) increase in real maize prices, and drier growing seasons are associated with modestly higher price. The heterogeneity analysis reveals that development level buffers the price effects of gradual temperature changes, whereas production capacity does not systematically moderate gradual climate shifts; extreme-heat effects are not moderated by either dimension; and drought effects strengthen with production scale. Extreme-heat price impacts are concentrated in net-exporting countries and thus propagate to world markets. These findings imply three policy pathways: coordinated global climate governance, multi-level price stabilization mechanisms, and country-specific support systems to contain climate-induced increases in maize price levels and safeguard global food security.