Unevenly distributed CO2 and its impacts on terrestrial carbon uptake under the changing land uses.

Changes in land-use structure and pattern can affect both atmospheric CO2 concentrations and the terrestrial carbon budget. To explore the effects of non-uniformly distributed CO2 concentration on terrestrial carbon uptake under land-use changes, this study integrated global CO2 concentrations, Net Primary Productivity (NPP), and land-use data under historical period and SSP1-2.6, SSP2-4.5 and SSP5-8.5 scenarios from 1850 to 2100. Land-use intensity (LUI) and the CO2 correlation to NPP were calculated using partial correlation analysis by controlling LUI. The results showed that NPP growth over the forest was the highest among the land-use types, reaching 0.54 g C·m2, 2.06 g C·m2 and 4.64 g C·m2, respectively, under SSP1-2.6, SSP2-4.5, and SSP5-8.5 scenarios. Among all the scenarios, the average correlation levels of atmospheric CO2 and NPP considering the LUI effect and controlling LUI ranged respectively from 0.34 to 0.68 and from 0.32 to 0.61 at a 5 % level of significance. It suggested that sensible land use planning might enhance the CO2 fertilization effect and that rises in CO2 concentrations could stimulate terrestrial carbon absorption. The findings add to the body of knowledge about the effects of atmospheric CO2 on terrestrial carbon uptake and serve as a scientific guide for protecting terrestrial carbon stocks and managing land use.

Global monthly gridded atmospheric carbon dioxide concentrations under the historical and future scenarios.

Increases in atmospheric carbon dioxide (CO2) concentrations is the main driver of global warming due to fossil fuel combustion. Satellite observations provide continuous global CO2 retrieval products, that reveal the nonuniform distributions of atmospheric CO2 concentrations. However, climate simulation studies are almost based on a globally uniform mean or latitudinally resolved CO2 concentrations assumption. In this study, we reconstructed the historical global monthly distributions of atmospheric CO2 concentrations with 1° resolution from 1850 to 2013 which are based on the historical monthly and latitudinally resolved CO2 concentrations accounting longitudinal features retrieved from fossil-fuel CO2 emissions from Carbon Dioxide Information Analysis Center. And the spatial distributions of nonuniform CO2 under Shared Socio-economic Pathways and Representative Concentration Pathways scenarios were generated based on the spatial, seasonal and interannual scales of the current CO2 concentrations from 2015 to 2150. Including the heterogenous CO2 distributions could enhance the realism of global climate modeling, to better anticipate the potential socio-economic implications, adaptation practices, and mitigation of climate change.

Impact of Epidemic-Affected Labor Shortage on Food Safety: A Chinese Scenario Analysis Using the CGE Model.

Human food safety should be given priority during a major public health crisis. As the primary element of agricultural production, labor tends to suffer the most during a period of public health concern. Studying the impact of epidemic-affected labor shortages on agricultural production, trade, and prices has important implications for food security. This study used a calculable general equilibrium model to study the changes in agricultural production, trade, and prices under different labor damage scenarios. The results showed that agricultural production was less affected under a scenario where the epidemic was controlled locally. The output of agricultural products decreased by about 2.19%, and the prices of agricultural products increased slightly. However, the nationwide output of agricultural products decreased by only 0.1%, and the prices remained largely stable. In the case of the spread of the epidemic, the output of agricultural products in the epidemic area decreased by 2.11%, and the prices of certain agricultural products increased significantly. For example, the price of vegetables increased by 0.78%, the price of pork increased by about 0.7%, and those of agricultural products in other parts of the country also increased slightly. Compared with the national spread scenario, the local outbreak scenario had a smaller impact on Chinese food security, indicating Chinese effective policy against the epidemic. Although the impact of labor shortage under the influence of the epidemic on China was relatively limited, and considering its stable food security, we should pay attention to the increase in the process of agricultural products and changes in agricultural trade in the epidemic area. The residents in the epidemic areas could not effectively obtain nutritious food, which affected their health. Thus, the government should also completely mobilize agricultural resources to ensure the nutrition safety of residents during major public health incidents.