Yao Huang

Significance Agricultural production is vulnerable to climate change. Understanding climate change, especially the temperature impacts, is critical if policymakers, agriculturalists, and crop breeders are to ensure global food security. Our study, by compiling extensive published results from four analytical methods, shows that independent methods consistently estimated negative temperature impacts on yields of four major crops at the global scale, generally underpinned by similar impacts at country and site scales. Multimethod analyses improved the confidence in assessments of future climate impacts on global major crops, with important implications for developing crop- and region-specific adaptation strategies to ensure future food supply of an increasing world population.

Significance Exceedingly high levels of fine particulate matter (PM) occur frequently in China, but the mechanism of severe haze formation remains unclear. From atmospheric measurements in two Chinese megacities and laboratory experiments, we show that the oxidation of SO 2 by NO 2 occurs efficiently in aqueous media under two polluted conditions: first, during the formation of the 1952 London Fog via in-cloud oxidation; and second, on fine PM with NH 3 neutralization during severe haze in China. We suggest that effective haze mitigation is achievable by intervening in the sulfate formation process with NH 3 and NO 2 emission control measures. Hence, our results explain the outstanding sulfur problem during the historic London Fog formation and elucidate the chemical mechanism of severe haze in China.

Significance China has launched six key ecological restoration projects since the late 1970s, but the contribution of these projects to terrestrial C sequestration remains unknown. In this study we examined the ecosystem C sink in the project area (∼16% of the country’s land area) and evaluated the project-induced C sequestration. The total annual C sink in the project area between 2001 and 2010 was estimated to be 132 Tg C per y, over half of which (74 Tg C per y, 56%) was caused by the implementation of the six projects. This finding indicates that the implementation of the ecological restoration projects in China has significantly increased ecosystem C sequestration across the country.