The evolution of territorial space is intrinsically linked to economic growth, societal welfare, and ecological preservation. In the context of escalating spatial conflicts and stringent resource limitations, resource efficiency has emerged as a fundamental pillar for the scientific optimization of territorial space layout. Drawing upon resource efficiency metrics from cities nationwide, this study constructs scenarios for territorial space development and conservation. It assesses developmental capacity under varying preferences and subsequently delineates strategic blueprints using an integrated "point-axis-area" approach. The findings reveal that: (1) Resource efficiency in China has witnessed a consistent uptick, yet remains modest overall, with marked regional disparities. (2) Throughout the investigation period, developmental capacity has seen progressive enhancement, with a pronounced capacity in scenarios favoring development, radiating axially from urban conglomerates. (3) The layout of pivotal points and developmental axes has transitioned from a "tri-pillar" to a diamond configuration, with the coastal corridor, the Harbin-Beijing-Guangzhou corridor and the corridor along the Yangtze River standing out. (4) Strategic points progressively converge along key axes, while dominant regions exhibit clear differentiation on either side of the Hu Huanyong Line. By integrating elements of the territorial spatial structure, this paper proposes blueprints for "five horizontal and three vertical zones with eight cores and three areas", "four horizontal and three vertical zones with six cores and three areas" and "three horizontal and four vertical zones with five cores and three areas", corresponding to scenarios prioritizing development, status quo maintenance, and conservation, respectively. The outcomes of this research offer a technical foundation and theoretical guidance for the pursuit of high-quality territorial space development and the vision of a picturesque landscape.

Spatial agglomeration is an important concept in geography. The study examines the effect of spatial agglomeration of construction land resources (SACL) on the synergistic reduction of pollutants and CO₂ (SRPC), which provides a geographical scheme for provincial governments in this aspect. In this paper, Kaya identity and ImPACT identity are first constructed based on the SACL, which is the theoretical analysis framework of this study. Then, the Gruebel-Lloyd index is used to measure the level of SRPC, and the Herfindahl index is used to identify the degree of SACL in provincial-level regions. The relationship between SACL and SRPC is tested using China's provincial panel data. The findings are as follows: （1）The scale of construction land has a negative effect on the SRPC, but the SACL helps to play a positive role. (2) SACL reduces pollutants emissions through technological innovation and reduces CO₂ emissions through energy conservation. Additionally, technological innovation plays a certain masking effect in the process of SACL to promote CO₂ emission reduction. (3) SACL has a U-shaped, inverted U-shaped, and U-shaped driving process on pollutant reduction, carbon reduction, and synergic emission reduction, respectively. But overall, the promotion effect is dominant, and only when SACL reaches a certain level can the positive synergistic effect be produced. (4) SACL has a regional heterogeneity effect on SRPC. In the eastern and central regions, SACL helps to reduce CO₂ emissions but does not achieve the goal of reducing pollution, thus does not produce a positive effect on SRPC. In the western region, SACL is beneficial for reducing emissions of pollutants and CO₂, resulting in a positive effect on SRPC.

The power sector is a critical industry in China's efforts to attain its carbon peaking and carbon neutrality targets. Analyzing the spatio-temporal pattern and influencing factors of the aggregate carbon intensity (ACI) of electricity generation at the city scale is of great significance for refining electricity emission reduction policies and guiding regional collaborative carbon reduction. This study utilizes micro-level data from 21543 power plants with a capacity of 6000 kW or above, in combination with multiple sources of statistical data related to energy, economy, and society, to calculate ACI of electricity generation in China's cities in 2003, 2010, and 2017. Exploratory spatial data analysis, IDA-LMDI decomposition, and STIRPAT modeling are employed to reveal the spatio-temporal patterns and influencing factors. The findings show that: (1) From 2003 to 2017, the ACI of China's electricity generation sector exhibited a notable decline, albeit with a trend of increasing internal differences. Significant spatial differentiation was observed at city scale, with the northeast half of the Bole-Taipei Line maintaining higher levels than the southwest half over an extended period. The degree of spatial agglomeration also increased significantly during this period, with Northeast and North China identified as regions of particular concern in the decline of ACI. (2) The thermal efficiency was the dominant factor in the decline of ACI in the early stage, whereas the electricity generation structure became increasingly influential in the later period. Meanwhile, other power system factors exhibited less influence, though significant spatial differences were observed. (3) The impact of diverse socio-economic determinants on ACI fluctuated over time, engendering modifications in the attributes of the power system through their interactions with the intricate network of power demand, policy, technology, and clean energy expansion opportunities. (4) An inverted U-shaped correlation was observed between ACI and per capita GDP in 2003 and 2010, which transformed into a linear positive association in 2017. This shift can be attributed to the swift emergence of renewable electricity that have challenged the traditional interpretive framework of the Environmental Kuznets Curve hypothesis, which was previously applicable only to thermal power generation. In the future, endeavors aimed at reducing emissions in the electricity sector must comprehensively acknowledge the spatial heterogeneity and sustain attention towards the ramifications of abrupt shifts arising from emerging technologies on the conventional theoretical framework.

The Grain for Green Program (GGP) is the most invested, policy-oriented, wide-embracing, and public-involving ecological restoration project in China, which has become the main driver of national greening and carbon sink increases; however, the large potential of carbon sink increases and their contribution to the program's carbon neutrality goal still lacks systematic estimation. Here, based on backdating of the GGP effect on increasing carbon sinks in the Beijing-Tianjin-Hebei (BTH) region over the past 20 years, three scenarios-sustainable development, benchmark, and regional competition-are combined under different climates, socioeconomies, and eco-planning patterns to forecast the potential for increasing carbon sinks and the contribution of the GGP in the "Double Carbon Target" years (2030 and 2060). Our results showed that: (1) During 2000-2020, the increase in carbon sinks exceeded 48.03 Tg C; among them, the ability of increased carbon sinks in the region to restore croplands to forests (GGP-Forest), which accounted for 23.9% of the total area, reached 123.7%. (2) In 2030, the annual increase in carbon sinks resulting from the GGP in the BTH region will reach 5.33-6.20 Tg C a^-1, up by 95.8%-127.7% compared with the year 2020. This can offset ~0.3% of the total carbon emissions from this region; however, this contribution can reach 30% at the county scale. (3) In 2060, the annual increase in carbon sinks resulting from the GGP in the BTH region will be about 4.35-4.88 Tg C a^-1, up by 59.7%-79.3% compared with 2020 and can offset 5.1%-7.2% of the total carbon emissions from this region; its contribution can reach eightfold at the county scale. In summary, it is essential to correctly quantify the contribution of the Double Carbon Target in the study region resulting from the ecological restoration program, especially in the northwest counties in the ecological conservation area, where the GGP can act as the main method to achieve carbon neutrality.

Global warming leads to increased frequency and severity of droughts, profoundly affecting the carbon budget of terrestrial ecosystems. We conducted a comprehensive assessment of drought trends within the Lancang-Mekong River Basin (LMRB) and quantified the impacts of standardized precipitation evapotranspiration index (SPEI), potential evapotranspiration (PET), vapor pressure deficit (VPD) and soil moisture (Soil_w) on net ecosystem productivity (NEP) using geographically weighted regression (GWR) method. The GWR analysis demonstrated that drought indices have a significant impact on NEP. From 2000 to 2019, with the decrease of precipitation, LMRB experienced a rise in temperature and a drop in humidity, leading to moderate or extreme drought in around 25% of the LMRB, especially between 2009 and 2016. Drought hotspots were identified in the upper reaches of the Lancang River and the middle and lower reaches of the Mekong River. Drought events in 2005, 2010, and 2019 altered the carbon source/sink of the Mekong River Basin ecosystem by decreasing plant photosynthesis and increasing ecosystem respiration. In 2010, for example, drought reduced GPP by 5.68% and increased ecosystem respiration by 3.15%, resulting the anomalies of NEP. The impact of drought on NEP in the LMRB often exhibited a lag effect, with an overall lag duration of 1 to 4 months, covering approximately 57.82% of the area. Spatial differences of the influence of different hydroclimatic factors on NEP were observed. NEP was negatively correlated with VPD in the LMRB, and positively correlated with SPEI in China's Yunnan province, western Myanmar, Cambodia and southern Vietnam. The NEP in the Qinghai-Tibet Plateau was mainly affected by soil drought. This study highlights the significant spatial heterogeneity in the impact of drought on ecosystem carbon sequestration within the LMRB, providing essential insights for ecological management in drought-affected areas.