Accelerated global urban expansion not only directly occupies surrounding ecosystems, but also induces cascading losses of natural vegetation elsewhere through cropland displacement. Yet, how such effects alter the net primary productivity (NPP) worldwide remains unclear. Here, we quantified the direct and cascading impacts of global urban expansion on terrestrial NPP from 1992 to 2020 and projected the impacts under the shared socioeconomic pathways framework by 2100.
View Article and Find Full Text PDFA concise and efficient synthesis of fully substituted cyclobutane derivatives from 1,4-diyn-3-ols and anhydrides was developed. Mechanistic studies indicated that a tandem esterification, isomerization to give allenyl ester, and homointermolecular [2+2] cycloaddition might be involved. The features of this protocol are its operational practicality, mild reaction conditions, and high regio- and stereoselectivity, and it is a readily accessible gram-scale synthesis.
View Article and Find Full Text PDFLand use change driven by human activities plays a critical role in the terrestrial carbon budget through habitat loss and vegetation change. Despite the projections of the global population and economic growth under the framework of the Shared Socioeconomic Pathways (SSPs), little is known of land use/cover change (LUCC) at a fine spatial resolution and how carbon pools respond to LUCC under different SSPs. This study projected the future global LUCC with 1 km spatial resolution and a 10-year time step from 2010 to 2100 and then explored its direct impacts on aboveground biomass carbon (AGB) under SSPs.
View Article and Find Full Text PDFIn response to carbon dioxide (CO) emissions, numerous studies have investigated the link between CO emissions and urban structures, and pursued low-carbon development from the standpoint of urban spatial planning. However, most of previous efforts only focused on urban structures in term of two-dimensional space, whereas the vertical influence of urban buildings (three-dimensional space) plays an important role in CO emissions. To address this issue, we took the cities in mainland China as study case to quantitatively explore how the three-dimensional urban structure affects CO emissions.
View Article and Find Full Text PDFDespite its small land coverage, urban land and its expansion have exhibited profound impacts on global environments. Here, we present the scenario projections of global urban land expansion under the framework of the shared socioeconomic pathways (SSPs). Our projections feature a fine spatial resolution of 1 km to preserve spatial details.
View Article and Find Full Text PDFJ Environ Manage
April 2020
Increasing water scarcity in China is further exacerbated by the rapid socio-economic development and uneven spatial distribution of water resources. Current studies on water footprint have mainly focused on historical accounting and trend analysis at the provincial scale. However, a comprehensive exploration of future water footprint would be vital to a better understanding of future water shortage challenges, and more importantly, would allow the mitigation of water scarcity and inequal water distribution.
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