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The spatiotemporal distribution of ecosystem service values (ESVs) and ecological risk are critical indicators to represent the regional ecological protection level and potential of sustainable development, which largely depend on land-use patterns. Aiming to contribute to global climate mitigation, China has proposed dual-carbon goals that would remarkably influence the land-use/cover change (LUCC) distribution. Based on the Landsat land cover data of 2000, 2010 and 2020 and multisource satellite products, several driving factors are integrated into the patch-generating land use simulation (PLUS) model to simulate future LUCC patterns for the Guangdong–Hong Kong–Macao Greater Bay Area (GBA) under rapid urbanization, cropland protection and carbon neutral (CN) scenarios from 2020 to 2050. Spatial–temporal ecosystem service and ESVs are allocated using INVEST and the equivalent factor method and thus ecological risks are evaluated using the entropy method. Results indicate that forest growth is the largest under the CN scenario, especially in the northwestern and northeastern GBA, exceeding 25,800 km2 in 2050, which results in both the highest habitat quality and carbon storage. The largest ESVs, reaching higher than 5210 yuan/pixel, are found in the CN scenario, particularly expanding toward the suburban area, leading to the lowest ecological risks. From 2020 to 2050, habitat quality, carbon storage and ESVs improve, while ecological risks decline in the CN scenario. This research provides implications for economic and ecological balanced development and gives references to the carbon-neutral pathway for the GBA. [ABSTRACT FROM AUTHOR]

• Proposal of a method to construct typical generic block models using local datasets. • Urban form influences strategy of solar technology in low-carbon scenario. • Solar cooling contributes to carbon reduction in subtropical areas. • Technology and morphology design can overcome the high-density constraints. The use of solar energy in an urban context is essential for low-carbon urban development and global climate change mitigation. In this paper, the application of multiple solar energy techniques, namely, photovoltaic (PV), photothermal (PT), and photothermal-driven cooling (PC) techniques, in tropical Macau was investigated. Based on the typological method, sixty generic block typologies were formulated. A parametric workflow was constructed to facilitate block modelling and simulate energy consumption and solar radiation. The optimal technique strategy for each typology was identified under a low-carbon scenario. The energy and environmental performance levels of the blocks were evaluated by calculating and comparing the solar potentials, load matching conditions, primary energy consumption levels, and carbon dioxide emissions. The results indicated that the PT technique should be preferred for blocks with high floor area ratio (FAR) values, while the PV technique should be prioritized for blocks with low FAR values under the low-carbon scenario. Moreover, the PC technique is necessary in subtropical areas to reduce carbon emissions. In addition, it is suggested that solar energy should be adopted in blocks with high site coverage ratio (SC) and low surface area-to-volume ratio (SAV) values, as well as blocks with low FAR values. Regarding blocks constrained by high-density urban development, appropriate decisions on technology and morphological design could help to overcome constraints and realize low-carbon community targets. This study could provide suggestions for urban planners and building designers in the application of the urban solar potential at the early stages of urban design or urban regeneration. [ABSTRACT FROM AUTHOR]

As Earth's warming is driven by anthropogenic activities (e.g., urbanization), land and ocean warming significantly affect the net carbon uptake (NCU) of global ecosystems. However, the driving mechanism of coupled land‐sea warming on the NCU under rapid urbanization in coastal areas remains poorly understood. Here, we used long‐term remote sensing and meteorological observation data combined with spatial analysis and multivariate statistical methods to study the impact of coupled land‐sea warming and urbanization on land net primary productivity (LNPP, a proxy of the net land carbon uptake) in the Guangdong‐Hong Kong‐Macao Greater Bay Area (GBA), a rapidly urbanizing and climatically vulnerable area of South China. We found that the total LNPP decreased by 0.40 TgC from 1985 to 2015 and declined suddenly after 2003, driven by the reduced relative humidity and increased vapor pressure deficit (VPD). The increased VPD was caused by coupled land‐sea warming, and the indirect effect (γ = −0.51, p < 0.001) of coupled land‐sea warming on LNPP variability was much stronger than the direct effect (γ = −0.16, p < 0.05). In addition to the severe decline in the LNPP (0.20 TgC) induced by coupled land‐sea warming, urbanization caused a large loss in LNPP (0.16 TgC), which accounted for 40% of the total LNPP loss. Our findings can support future predictions of regional carbon uptake and inform future climate change mitigation strategies to implement carbon peak and neutrality goals. Plain Language Summary: Climate warming driven by rapid industrialization and urbanization has altered the processes and functions of global ecosystems. However, how the interaction of land/sea warming affects vegetation productivity and the carbon cycle in coastal areas is not clear. Here, a cascading effect of coupled land‐sea warming on the net carbon uptake (NCU) variability was detected in the Guangdong‐Hong Kong‐Macao Greater Bay Area (GBA), the area with the most rapid urbanization and climate warming in South China. Climate warming and urban sprawl, driven by urbanization, caused a consistent reduction in the net carbon uptake from 1985 to 2015 across all types of land cover in the GBA. A turning point of a sudden decline in net carbon uptake was detected when the vapor pressure deficit increased and the land/sea surface temperature sharply increased after 2003. An increased vapor pressure deficit, associated with coupled land‐sea warming, was the primary driver of reduced net carbon uptake. Our findings can support future predictions of regional carbon sinks and inform future climate change mitigation strategies from a coupled land‐sea warming perspective. Key Points: The cascading effect of coupled land‐sea warming on the net carbon uptake (NCU) variability was detectedThe increased vapor pressure deficit directly drove the NCU decrease after 2003, which caused more than 50% of the total lossUrbanization‐induced NCU loss aggravated the decline in the carbon sequestration function, accounting for 40% of the total loss [ABSTRACT FROM AUTHOR]

Greenhouse gas (GHG) emissions from energy consumption have become a major focus all over the world. Cities, especially, are playing an important role in responding to the challenges of global climate change. However, there is still a lack of case studies on the whole life stage (including energy import, production, and consumption) at the city level. This is the first study to systematically estimate the whole lifecycle GHG emissions of urban energy consumption in Macau using the life cycle assessment (LCA) method. It identifies the main contributors, draws the balance framework diagram of energy GHG emissions, and proposes the effective reduction measures through a scenario analysis. The results show that the total GHG emissions of energy consumption in Macau increased from 2.10 × 103 kt CO 2 eq. in 2000 to 5.34 × 103 kt CO 2 eq. in 2018. In 2018, the energy-related GHG emissions in the import phase, production phase, and consumption phase were 3.37 × 103, 4.08 × 102 and 5.34 × 103 kt CO 2 eq., respectively. Since the return of Macau from Portugal to China (December 20, 1999), its GHG emissions from energy import have come to depend more on Mainland China, increasing from 71% in 2000 to 98% in 2018. For the consumption phase, indirect GHG emissions are more important, accounting for 75.3% of total GHG emissions in Macau. From the final consumption perspective, the gambling industry results in the largest GHG emissions (38.07% in 2018), followed by the transportation industry; while for the final energy consumption types, electricity consumption has become the predominant source. The scenario analysis shows that under an ideal scenario, the GHG emissions can be slowed down and will peak in 2033. [Display omitted] • It firstly estimates the whole lifecycle GHG emissions from Macau urban energy consumption. • The GHG emission dependence on the mainland China increases from 71% to 98% since 2000. • It draws the balance framework diagram of energy GHG emissions. • Gambling industry results in the largest GHG emissions in Macau. • Under ideal scenario, the GHG emissions will peak in 2033. [ABSTRACT FROM AUTHOR]