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Fossil fuel (FF) CO 2 emissions account for the largest portion of human-related CO 2 emissions. It is essential to accurately understand the spatial distribution of high-resolution FFCO 2 emissions to formulate different carbon emission reduction policies in different regions. Therefore, a sectoral allocation approach was proposed to estimate FFCO 2 emissions in China from 2000 to 2021 based on multi-source data. Furthermore, the spatiotemporal characteristics of FFCO 2 emissions in different sectors were analyzed at different scales, and the spatial correlation of FFCO 2 emissions in the service sector and industrial sector was also evaluated through Moran's index. The results showed that the mean R2 value of the sectoral allocation approach (0.89) exceeds that of the approach using only nighttime light (0.72). Moreover, the calculated results were utilized to analyze the Spatiotemporal variation of FFCO 2 emissions. The analysis revealed that China's FFCO 2 emissions increased from 3173 Mt in 2000–10662 Mt in 2021. The high emissions of FFCO 2 mainly come from the industrial sectors in North China and Central China, as well as the service sectors in the eastern coastal cities and other provincial capital cities. The spatial dependence of FFCO 2 emissions in the industrial sector was stronger than that in the service sector, but the spatial dependence of FFCO 2 emissions in the service sector showed an increasing trend from 2000 to 2021. These results have important references and implications for region-specific carbon emission reduction policies. [Display omitted] • A new sectoral approach was proposed to estimate fossil fuel (FF) CO 2 emissions. • The FFCO 2 emissions of different sectors was compared comprehensively. • The FFCO 2 emission data of different sectors on the grid scale were calculated. • The spatial correlation was compared between service sector and industrial sector. [ABSTRACT FROM AUTHOR]

Long-lasting drought records can provide valuable insights into the history of hydroclimate change in central China, but meteorological records are too short to capture long-term variability of the humidity. In this study, we established a tree-ring width chronology of Pinus armandii Franch in the Funiu Mountains region of central China. Correlation analyses showed that tree radial growths were mainly limited by hydrothermal combination in May–June. The results of the moving correlation analysis further showed that the response relationship between tree growth and relative humidity in May–June (RH MJ) was the most stable. This relationship has been reconstructed since 1863. The variance of the reconstructed RH MJ was explained by 41.7% (40.6% after adjusting for degrees of freedom). Over the past 158 years, there were 3 wet periods and 4 dry periods. The spectral analysis revealed that the reconstructed RH MJ exhibited quasi-periods of 2-4a and 31.6a, and cross-spectrum analysis showed that the reconstructed RH MJ may be related to ENSO, PDO, solar activity and the East Asian summer monsoon. The spatial correlation analysis revealed that the reconstructed RH MJ accurately depicted the fluctuations in humidity within the Huanghe-Huaihe Plain. Furthermore, the reconstructed RH MJ exhibited a strong negative correlation with the sea surface temperature (SST) of the subtropical North Pacific, while it displayed a highly significant positive correlation with the SST of the eastern equatorial Pacific from the previous May to the current April. This also indicated a possible link between humidity fluctuations in the Huanghe-Huaihe Plain and the Pacific internal variability in climate system. Therefore, this research aims to expand and complement the existing meteorological records, providing important reference significance for forest management, agriculture, and animal husbandry. [ABSTRACT FROM AUTHOR]

Climate transition zone is a sensitive area of climate change and ecological transition where forests are vulnerable to climate extremes. Extreme droughts are increasing in frequency and magnitude under climate change, resulting in structure and function changes of forest ecosystems. Here, to analyze climate-growth relationships and quantify tree resilience to extreme droughts, we developed six tree-ring-width chronologies from P. tabulaeformis and P. massoniana sampling sites in Mt. Jigong region, Central China. The results indicated that all chronologies from the two species had good consistency, precipitation in current April and mean temperature in current August or mean minimum temperature from current August to October were the main limiting factors of the two tree species growth, but the responses of P. massoniana ring-width to climatic factors was more complex than that of P. tabulaeformis. The results also showed that tree growth of 1999–2005 was the lowest growing period during 1979–2018, and P. massoniana grew better than P. tabulaeformis before 2005 and vice versa after 2005. Comparing low growth years of trees, we identified to study tree growth resilience. The calculations from 1988, 1999–2005 and 2011 drought years indicated that P. tabulaeformis had more increased resilience to extreme droughts than that of P. massoniana , and the two species had stronger ecological recovery and resilience under global warming and non-extreme drought conditions in the recent 40 years. These results have implications for predicting tree resilience and identifying tree species in heterogeneous forest landscapes vulnerable to future climate change in climatic transition zone. • A climate transitional zone and two climate-sensitive tree species. • The climatic limiting factors for the growth of the two tree species have a good consistency. • The growth resilience to extreme drought events was significantly different between the two species. [ABSTRACT FROM AUTHOR]

• Novel low-temperature process for backsheet removal proposed. • A novel perspective on the separation of c-Si PV modules from back metallization. • The fluorinated backsheet ensures no release of hazardous fluoride. • About a 70% reduction in the thermal weight loss ratio compared to direct thermal treatment. With the significant growth in the production and installation of photovoltaic (PV) systems, the recycling of end-of-life PV modules has become a critical concern. Thermal treatment is a promising approach to decompose all the polymer and separate different layers rapidly. However, the combustion of the backsheet can lead to the release of hazardous fluorinated compounds. This paper proposes a novel method combining low-temperature and thermal treatment to separate different layers in PV modules. This method leverages the back metallization of solar cells for PV module separation, providing a fresh separation perspective. The focus lies on investigating a low-temperature separation process, and the separation interfaces are characterized using SEM and EDS, shedding light on the separation position and physical separation mechanisms. Subsequently, the effects of different freezing temperatures, freezing times, and different laminated parts were investigated, and the processing parameters were optimized. Compared to direct thermal treatment, the proposed process eliminates the generation of hazardous fluorides and mitigates mass losses caused by thermal treatment effectively. This research provides valuable insights into the green and sustainable resource recovery of waste PV modules. [ABSTRACT FROM AUTHOR]

• Tree ring is an ideal indicator of annual total grain production parameters. • Tree growth synchronized with grain production, and concurrent response to climate. • Reconstruction of total grain productivity based on dendrochronology. • To explore the relationship between total grain sown area and climate change. Climate change affects the growth of regional vegetation; both trees and grain crops often change concurrently, such that the annual radial growth of trees shows consistent inter-annual variations with the total grain crop productivity. However, it remains unclear whether they exhibit concurrent responses to climate factors, and that there lacks of the study on long-term high-resolution variations of grain crops productivity. This paper employs a Pinus massoniana tree-ring series from the Tongbai Mountains to analyze the correlations between tree-ring chronology, local climate data and grain productivity indicators (i.e., total sown grain areas (TSA), total grain outputs (TGO), and average grain yield per hectare (YPH)) of Henan Province in central China. The results indicate that temperature in March and August was the main limiting factor on tree growth, and the best concurrent relationship with tree growth was TSA, which has a correlation of 0.747 (p < 0.001) during 1959–2020. Therefore, a 124-year TSA series in Henan Province was reconstructed using tree-ring data from the Tongbai Mountains, which reveals there were two distinct low periods of total grain sown area in the 1920 s-1930 s and 1980 s-2000 s. There are significant cycles of about 2.57a (p < 0.01), 2.89a (p < 0.05), and 10.95a (p < 0.1), indicating that vegetation growth might be affected by large-scale climate forcing, such as ENSO (2-7a cycle) and sunspot activity (11a cycle). Overall, this study outlines a new approach to understand long-term changes in grain production, which is conducive to grain management and socioeconomic sustainability. [ABSTRACT FROM AUTHOR]