Global Reduction Research Articles

Quantifying and categorizing development paths of poverty-elimination counties in China: Based on the perspective of population-land-industry

China has achieved the poverty reduction goal of the United Nations 2030 Agenda for Sustainable Development 10 years ahead of schedule, contributing significantly to global poverty reduction. Despite extended efforts in poverty elimination, there is a lack of quantitative studies categorizing and comparing poverty-elimination counties (PECs) based on their processes. This study proposes an innovative framework for analyzing PECs’ development paths from the perspective of population-land-industry (PLI). We quantify the PLI matching degree of PECs in China during the critical phase of the battle against poverty through a multivariate matching model, classify PECs via K-means clustering according to the consistency in PLI matching degree evolution, and summarize the typical development patterns of PECs. Results indicate that the PLI matching degree of PECs in China increased substantially from 2015 to 2020, particularly in eastern areas, while the western region, including the Qinghai-Xizang Plateau and southwestern Xinjiang, shows untapped potential for improvement. Five types of PECs are identified, with the majority (30.1%) showing sustained moderate PLI matching and a minority (9.6%) experiencing long-term PLI mismatch. Industry is the shortfall of various PECs, and effective strategies to facilitate all types of PECs include the development of emerging businesses and the expansion of secondary and tertiary industries. Additionally, enriching rural labor force and increasing farmland use efficiency are essential for optimal PLI matching and positive interaction, ultimately ensuring poverty elimination and sustainable development.

IMO2020 Regulations Accelerate Global Warming by up to 3 Years in UKESM1

AbstractThe International Maritime Organization (IMO) introduced new regulations on the sulfur content of shipping emissions in 2020 (IMO2020). Estimates of the climatic impact of this global reduction in anthropogenic sulfate aerosols vary widely. Here, we contribute to narrowing this uncertainty with two sets of climate model simulations using UKESM1. Using fixed sea‐surface temperature atmosphere‐only simulations, we estimate an IMO2020 global effective radiative forcing of 0.139 ± 0.019 Wm−2 and show that most of this forcing is due to aerosol‐induced changes to cloud properties. Using coupled ocean‐atmosphere simulations, we note significant changes in cloud top droplet number concentration and size across regions with high shipping traffic density, and—in the North Atlantic and North Pacific—these microphysical changes translate to a decrease in cloud albedo. We show that IMO2020 increases global annual surface temperature on average by 0.046 ± 0.010°C across 2020–2029; approximately 2–3 years of global warming. Furthermore, our model simulations show that IMO2020 helps to explain the exceptional warming in 2023, but other factors are needed to fully account for it. The year 2023 also had an exceptionally large decrease in reflected shortwave radiation at the top‐of‐atmosphere. Our results show that IMO2020 made that more likely, yet the observations are within the variability of simulations without the reduction in shipping emissions. To better understand the climatic impacts of IMO2020, a model intercomparison project would be valuable whilst the community waits for a more complete observational record.

Addressing Impacts from Climate Change Within International Legal System: More Precise Distribution of Responsibilities

As the international challenges resulting from climate change become emergent, how to reform international law and institutions to reduce the effects of climate change has become a crucial issue. This paper carries out surveys on regulating and restructuring the present international law system about current issues and provides suggestions for further practice. We can also consider building a climate club. The existing climate regulation mechanism needs to improve, leading to problems such as carbon leakage and free riding. Climate clubs can urge countries to fulfill their obligations by rewarding member states that fulfill their obligations and cracking down on non-member states. Apart from efforts in environmental governance, the international law system should also attach attention to the issue of climate refugees as a reaction to climate change. The last article argues that international society should provide legal protection for climate refugees, and it is reasonable for them to acquire a formally defined legal status for future humanitarian care. This thesis also explores the potential role of regional bodies in addressing climate change outside of the United Nations Framework Convention on Climate Change (UNFCCC) and the legitimacy of their responsibilities based on constitutional treaties, their role in regulating the international commons, and their relationship to the UNFCCC. Based on this, this thesis suggests that regional institutions take on more responsibility in regulating state obligations and propose possible solutions to the climate change crisis. CBDR is an essential principle in the cooperation among countries to solve the problem of global climate change. It makes global cooperation fairer and more effective but also generates some problems. The main problem is that there is no clear division of responsibilities between countries, and policies must be implemented. This paper proposes three ways to divide responsibilities and argues that companies must actively participate in global emission reduction activities.

Regional gray matter changes in steatotic liver disease provide a neurobiological link to depression: A cross-sectional UK Biobank cohort study

BackgroundSteatotic liver disease (SLD) is characterized by excessive accumulation of lipids in the liver. It is associated with elevated risk of hepatic and cardiometabolic diseases, as well as mental disorders such as depression. Previous studies revealed global gray matter reduction in SLD. To investigate a possible shared neurobiology with depression, we examined liver fat-related regional gray matter alterations in SLD and its most significant clinical subgroup metabolic dysfunction-associated steatotic liver disease (MASLD). MethodsWe analyzed regional cortical thickness and area obtained from brain MRI in 29,051 participants in UK Biobank. Liver fat amount was computed as proton density fat fraction (PDFF) from liver MRI scans. We examined the relationship between brain structure and PDFF, adjusting for sociodemographic, physical, lifestyle, and environmental factors, as well as alcohol intake and a spectrum of cardiometabolic covariates. Finally, we compared patterns of brain alterations in SLD/MASLD and major depressive disorder (MDD) using previously published results. ResultsPDFF-related gray matter alterations were region-specific, involving both increases and decreases in cortical thickness, and increased cortical area. In several regions, PDFF effects on gray matter could also be attributed to cardiometabolic covariates. However, PDFF was consistently associated with lower cortical thickness in middle and superior temporal regions and higher cortical thickness in pericalcarine and right frontal pole regions. PDFF-related alterations for the SLD and the MASLD group correlated with those observed in MDD (Pearson r = 0.45–0.54, p < 0.01). ConclusionThese findings suggest the presence of shared biological mechanisms linking MDD to SLD and MASLD. They might explain the well-known elevated risk of depression in these groups and support early lifestyle interventions and treatment of metabolic risk factors for the successful management of the interconnected diseases depression and SLD/MASLD.

Study on the development path of low-carbon retail clusters empowered by digital empowerment

This study provides an in-depth exploration of the mechanisms by which wholesale and retail clusters in China influence green and low-carbon synergistic development. Using the system generalized method of moments (SYS-GMM) method combined with the theory of industrial clusters, the contribution of digital technology application, green supply chain management, consumer behaviour, and corporate social responsibility to synergistic development is analyzed. It is found that the highly clustered wholesale and retail industry has promoted supply chain intelligence and logistics optimization through the extensive application of digital technology, creating favourable conditions for synergistic development. Regarding green supply chain management, cluster companies are more inclined to adopt green measures such as environmentally friendly packaging and energy-efficient logistics, effectively reducing carbon emission levels. In terms of consumer behaviour, the increase in the clustering rate has prompted consumers to be more inclined to consume green and purchase green products, thus promoting the decarbonization of products and services. CSR practices show that highly clustered companies are more active in implementing emission reduction measures, reflecting their responsibility for sustainable development. This study provides a new theoretical perspective for understanding the intrinsic mechanism of industrial clusters in carbon emission reduction and offers feasible carbon reduction strategies for industrial practices. In the urgent global carbon emission reduction context, this study provides essential academic and practical value for promoting China's wholesale and retail industry toward more sustainable development.

Strategic dimensions of solar geoengineering: Economic theory and experiments

Solar geoengineering denotes a set of technologies that would enable a fast and relatively cheap global temperature reduction. Besides potential physical side-effects, a major concern is the strategic dimension: Who is going to use solar geoengineering and how would it affect others? How does the presence of solar geoengineering change the strategic incentives surrounding other climate policy instruments such as mitigation? We review the existing theoretical and experimental contributions to those questions and outline promising lines of future economic research.

Sensitivity of the global hydrological cycle to the altitude of stratospheric sulphate aerosol layer

Abstract Stratospheric aerosol geoengineering (SAG) has been proposed as one of the potential options to offset the impacts of anthropogenically induced climate change. Previous modelling studies have shown that the efficacy of the cooling via SAG increases with altitude of the aerosol layer. It has been also shown that the stratospheric heating associated with SAG could stabilize the tropical atmosphere and weaken the tropical hydrological cycle. Using a global climate model, we perform a systematic study by prescribing volcanic sulphate aerosols at three different altitudes (22 km, 18 km and 16 km) and assess the sensitivity of the global and tropical mean precipitation to the altitude. We find that even though the efficacy of cooling increases with altitude of the aerosol layer, the global and tropical mean precipitation changes are less sensitive to the height of the aerosol layer. This is because the magnitude of both the global and tropical mean precipitation reduction increases with aerosol altitude in response to increasing efficacy of aerosols, but this sensitivity related to the slow response is nearly offset by the sensitivity of fast precipitation adjustments to aerosol altitude. A perspective and analysis based on atmospheric energy budget is presented to explain the lack of sensitivity of the hydrological cycle to the altitude of the stratospheric sulphate aerosol layer.

Network intervention analysis indicates that roluperidone achieves its effect on negative symptoms of schizophrenia by targeting avolition

Roluperidone, a 5-HT2A, sigma2, and ɑ1A-adrenergic receptor antagonist, has proven efficacious for treating negative symptoms of schizophrenia in phase 2b and phase 3 clinical trials. Using network analysis, we demonstrated that the improvements observed in the phase 2b trial resulted from targeting avolition which was highly central and spurred a cascading effect of global negative symptom reductions when successfully treated. The current study aims to replicate these network findings using the phase 3 roluperidone clinical trial data. Participants included 496 schizophrenia patients with moderate to severe negative symptoms who were randomized to either roluperidone 32 mg/day (n =167), 64 mg/day (n = 162), or placebo (n = 167). Negative symptoms were assessed at baseline and weeks 2,4,8, and 12. Network intervention analysis (NIA) evaluated treatment-induced symptom changes over time to identify direct and indirect treatment effects. This analytic approach extends prior work by determining whether the symptoms with highest centrality have causal effects on the entire negative symptom construct and directly lead to symptom improvement. NIA indicated that the efficacious 64 mg/day dose of roluperidone had a direct effect on avolition, suggesting that changes in avolition propels treatment effects across the entire negative symptom constellation. These phase 3 findings replicated the phase 2b findings, indicating that from a network perspective, roluperidone achieves its effect by influencing the extent to which avolition drives other negative symptoms. These findings are relevant for understanding negative symptoms and how to treat them in neuropsychiatric disorders.

Phytomedical compounds as promising therapeutic agents for COVID-19 targeting angiotensin-converting enzyme 2: a review.

The aim of the present review was to highlight natural product investigations in silico and in vitro to find plants and chemicals that inhibit or stimulate angiotensin-converting enzyme 2 (ACE-2). The global reduction of incidents and fatalities attributable to infections with SARS-CoV-2 is one of the most public health problems. In the absence of specific therapy for coronavirus disease 2019 (COVID-19), phytocompounds generated from plant extracts may be a promising strategy worth further investigation, motivating researchers to evaluate the safety and anti-SARS-CoV-2 effectiveness of these ingredients. To review phytochemicals in silico for anti-SARS-CoV-2 activity and to assess their safety and effectiveness in vitro and in vivo. The present review was conducted using various scientific databases and studies on anti-SARS-CoV-2 phytochemicals were analyzed and summarized. The results obtained from the in silico screening were subjected to extraction, isolation, and purification. The in vitro studies on anti-SarcoV-2 were also included in this review. In addition, the results of this research were interpreted, analyzed, and documented on the basis of the bibliographic information obtained. This review discusses recent research on using natural remedies to cure or prevent COVID-19 infection. The literature analysis shows that the various herbal preparations (extracts) and purified compounds can block the replication or entrance of the virus directly to carry out their anti-SARS-CoV-2 effects. It is interesting to note that certain items can prevent SARS-CoV-2 from infecting human cells by blocking the ACE-2 receptor or the serine protease TMPRRS2. Moreover, natural substances have been demonstrated to block proteins involved in the SARS-CoV-2 life cycle, such as papain- or chymotrypsin-like proteases. The natural products may have the potential for use singly or in combination as alternative drugs to treat/prevent COVID-19 infection, including blocking or stimulating ACE-2. In addition, their structures may provide indications for the development of anti-SARS-CoV-2 drugs.

Decoupling the climate walk from the climate talk: Evidence from Australia

AbstractA lack of regulation around greenhouse gas (GHG) emissions has led Australian companies to employ arbitrary targets for measuring GHG emissions reduction, which are not translating to the level of emissions reduction required to meet global targets. Despite the well accepted urgency of climate change action, there is a gap in literature with no studies discussing the effectiveness of the various targets for measuring GHG emissions to meet global emission reduction goal. Using correlation and ordinary least squares (OLS) regression analysis, our study of Australian Stock Exchange listed companies shows that the targets suggested by Task Force on Climate‐related Financial Disclosure (TCFD) are the most closely associated with the required emissions reduction. The findings from this study advocate that organisations adopt TCFD recommendations for achieving optimal reduction of greenhouse gas emissions to meet the global targets. Our findings should inform policymakers and practice to align targets to the TCFD recommendations to meet the global emissions reduction commitments and mitigate the most severe impacts of climate change.

Low-carbon oriented planning of shared photovoltaics and energy storage systems in distribution networks via carbon emission flow tracing

With the targets of carbon peaking and carbon neutrality, carbon emission reduction measures have become significant issues in new-type power systems. Distribution networks (DNs), which multiple power sources and flexible loads access to, play an essential role in exploiting the potential of reducing carbon emissions on the demand side. To achieve a global carbon emission reduction considering the carbon quota of each customer, shared photovoltaics (PVs) and energy storage systems (ESSs) are allocated with a centralized calculation and optimization conducted by DNs. To solve two key points in demand-side planning of shared PVs and ESSs in distribution networks, i.e., the accuracy of carbon emission flow (CEF) calculation and carbon quota-oriented optimization planning, this paper proposes a low-carbon oriented planning method for shared PVs and ESSs via CEF tracing. Firstly, a novel CEF calculation method is proposed based on the forward current sweep and backward voltage sweep algorithm, which considers the tracing of reactive power and power losses. Next, carbon emission index and economic index of allocating shared PVs and ESSs are defined. Subsequently, a bi-level optimization model is presented, considering the excess carbon emissions of each load based on carbon accounting and carbon quotas. Finally, the superiority of the proposed method is verified through a modified IEEE 33-node distribution network, and the effects of various investment constraints and carbon quotas are discussed.

First-Come-First-Served as a Separate Principle

A lock is a mechanism to guarantee mutual exclusion with eventual progress, i.e., some degree of fairness. First-come-first-served (FCFS) progress is perfectly fair. FCFS progress can be offered by a locking algorithm or added by wrapping a non-FCFS lock with a separate FCFS algorithm. A new separate FCFS algorithm is presented that creates FCFS progress by wrapping a lock’s entry protocol (acquire). The algorithm addresses an important safety issue in locking, called barging, where arriving threads proceed before waiting threads or waiting threads are serviced with some bias. Barging increases latency for waiting threads and is non-intuitive to concurrent programmers, even though it is inherent to non-deterministic concurrent execution. A correctness proof is presented for the new FCFS algorithm and verified with the proof assistant PVS. Experimental tests are performed to ensure the presented wrapper provides FCFS progress when used to transform non-FCFS software and hardware locks. The performance of the non-FCFS and transformed FCFS counterparts is compared, and contrasted with locks using inherent FCFS progress. The results show the FCFS transforms are performant for most algorithms, providing an additional tool for application developers to achieve correctness without a significant global performance reduction.

In-Person and Teleconsultation Services at a National Hospital in Peru: Time Series Analysis of General and Psychiatric Care Amid the COVID-19 Pandemic.

The COVID-19 pandemic led to a global reduction in health care accessibility for both infected and noninfected patients, posing a particular burden on those with chronic conditions, including mental health issues. Peru experienced significant devastation from the pandemic, resulting in a collapsed health care system and leading to the world's highest per capita mortality rate as a result of COVID-19. Understanding the trends in health care utilization, particularly in mental health care, is crucial for informing pandemic response efforts and guiding future recovery strategies. This study aims to analyze the trends of outpatient medical and psychiatric consultations during the COVID-19 pandemic in a national hospital in Peru. This observational study was conducted at a national hospital in Lima, Peru. We analyzed data on user care across all services, including psychiatric services, from May 2019 to December 2022. The data were calculated for users served per month, including the number of users seen monthly in mental health services. Sociodemographic variables such as sex (female or male), age (≥0 years), type of medical appointment (regular or additional), and modality of care (in-person or teleconsultations) were taken into account. An interrupted time series regression model was conducted to assess the number of outpatient medical and psychiatric consultations. Subgroup analyses were performed based on service modality, including overall consultations, telemonitoring/teleconsultations only, or face-to-face only, for all service users and for mental health service users. A total of 1,515,439 participants were included, with females comprising 275,444/484,994 (56.80%) of the samples. Only 345,605/1,515,439 (22.81%) visits involved telemedicine. The total monthly outpatient visits were significantly reduced compared with the expected projection (P<.001) at the beginning of the pandemic, followed by a later monthly increment of 298.7 users. Face-to-face interventions experienced a significant reduction at the beginning of the pandemic (P<.001), gradually recovering in the following months. By contrast, telemedicine use initially increased but subsequently declined toward the end of the pandemic. A similar trend was observed in mental health units. During the pandemic years, health care utilization in both general and psychiatric services experienced a significant decrease, particularly at the beginning of the pandemic (March 2020). However, no significant trends were observed in either case throughout the pandemic period. Telemedicine consultations witnessed a significant increase overall during this period, particularly among mental health users.

Genetically-Based Active Flow Control And PIV Measurements Of A Circular Cylinder Wake

In the field of flow manipulation, considerable attention is devoted to controlling the wake of bluff bodies, which are characterized by the phenomenon of vortex shedding. Specifically, the control of the wake behind a single circular cylinder has garnered substantial research interest due to its engineering applications, such as reducing aerodynamic drag in the automotive and aerospace industries. Therefore, in the current work, through the application of the planar PIV technique, the fluid dynamic behavior of a circular cylinder wake controlled via synthetic jets (SJ) and Machine Learning (ML) methods is analyzed and discussed. ML algorithms are used to determine the optimal voltage signal for the loudspeaker, which effectively minimizes the aerodynamic drag of the cylinder. This approach overcomes the limitations associated with the a priori assumption of a parametric waveshape. In particular, the gradient-enriched machine learning control (gMLC) algorithm is chosen as optimization tool to search the best open-loop control policy for aerodynamic drag reduction. The cost function for this problem has been defined considering both the drag reduction contribution and the electrical power spent for the actuation. Initial optimization tests are performed by minimizing a cost function considering only the reduction in aerodynamic drag. Subsequently, a term related to the electrical power consumption for actuation is incorporated into the cost function. Once obtained the optimal control policies for these cases (hereinafter renamed CC1 and CC2, respectively), the physical mechanism responsible for reducing the aerodynamic drag is investigated more closely by analyzing the effect of the control laws on the turbulent flow statistics. Figure 1 reports a comparative assessment of the CC1 and CC2 with the baseline configuration and the configuration controlled by a sinusoidal law (CCS). The baseline configuration is characterized by an extended region of localized turbulent fluctuations in the far wake, where the time-averaged signature of von Kármán vortices is found. In contrast, all the controlled configurations show a global reduction in wake turbulence, with a peak of turbulent energy at the rear stagnation point due to the momentum injection from the SJ actuator. Notably, the CCS and CC2 configurations share similar flow field morphologies, while the CC1 configuration shows a greater reduction in turbulent fluctuations compared to the other controlled cases. This control law also achieves the largest drag reduction among all configurations studied reporting a 9.7% of drag reduction, compared to CCS and CC2, which exhibit similar reductions of 8.4% and 8.5%, respectively. Therefore, the optimization procedure has proven the capability of finding control policies able to outperform the traditional sinusoidal control widely studied in literature.

Microglia depletion leads to increased susceptibility to ocular hypertension-dependent glaucoma.

In recent years, microglia have been highlighted for playing integral roles in neurodegenerative diseases, like glaucoma. To better understand the role of microglia during chronic ocular hypertension, we depleted microglia from aged (9-12 months old) DBA/2 J (D2) mice, which exhibit age-related increases in intraocular pressure, using a dietary CSF1R antagonist, PLX5622. Retinal ganglion cell (RGC) somas were counted, and optic nerve cross-sections stained and assessed for glaucomatous damage. Sustained administration of dietary PLX5622 significantly reduced the numbers of retinal microglia. Dietary PLX5622 did not lead to changes in intraocular pressure in D2 or normotensive DBA/2 J-Gpnmb+ (D2-Gpnmb+ ) control mice. While PLX5622-treated D2-Gpnmb+ did not develop optic nerve damage, PLX5622-treated D2 mice showed a significant increase in moderate-to-severe optic nerve damage compared to D2 mice fed a control diet. In conclusion, global reduction of microglia exacerbated glaucomatous neurodegeneration in D2 mice suggesting microglia play an overall beneficial role in protecting from ocular hypertension associated RGC loss.

Molecular basis of neurodegeneration in a mouse model of Polr3-related disease.

Pathogenic variants in subunits of RNA polymerase (Pol) III cause a spectrum of Polr3-related neurodegenerative diseases including 4H leukodystrophy. Disease onset occurs from infancy to early adulthood and is associated with a variable range and severity of neurological and non-neurological features. The molecular basis of Polr3-related disease pathogenesis is unknown. We developed a postnatal whole-body mouse model expressing pathogenic Polr3a mutations to examine the molecular mechanisms by which reduced Pol III transcription results primarily in central nervous system phenotypes. Polr3a mutant mice exhibit behavioral deficits, cerebral pathology and exocrine pancreatic atrophy. Transcriptome and immunohistochemistry analyses of cerebra during disease progression show a reduction in most Pol III transcripts, induction of innate immune and integrated stress responses and cell type-specific gene expression changes reflecting neuron and oligodendrocyte loss and microglial activation. Earlier in the disease when integrated stress and innate immune responses are minimally induced, mature tRNA sequencing revealed a global reduction in tRNA levels and an altered tRNA profile but no changes in other Pol III transcripts. Thus, changes in the size and/or composition of the tRNA pool have a causal role in disease initiation. Our findings reveal different tissue- and brain region-specific sensitivities to a defect in Pol III transcription.

Visual analysis of changes in European air transport during the COVID-19 pandemic from interactive maps

Abstract The paper explores the substantial decline in European air transport during 2020, while employing interactive maps for visual analysis. According to the International Civil Aviation Organization’s (2020) economic analysis, there was a sharp 60% global reduction in passenger traffic during the combined second, third, and fourth quarters, equivalent to about 2.7 billion fewer passengers than in 2019. The established air traffic flow, which developed over decades, faced partial disruption due to COVID-19 restrictions. Consequently, the aviation industry strategically focused on restructuring to ensure the sustained operation of major air transport routes. Using OpenSky Network data and a Google Sheets environment for storage, our study utilizes the FlowmapBlue interactive platform to visualize the 2020 European airspace, and to define key air traffic corridors. Despite the substantial decline, the visualization reveals resilient routes and crucial connections, underscoring the imperative of preserving these links for effective crisis response in the future.

Evaluating Climate Change Mitigation Strategies of G20 Countries: Policies, Actions, and Progress Towards Global Emission Reduction Goals

The G20 countries are responsible for over 75% of the greenhouse gas (GHG) emissions at a global level. The research summarises the role of G20 countries in combating Climate Change. This research study explores the comprehensive assessment of the G20 nations’ policies and the impacts of climate change across the globe. The paper studies the policies of the G20 countries’ governments to meet the Nationally Determined Contribution (NDC) target and achieve the global goal of the Paris Agreement (or COP28) and Net Zero Emissions Target of limiting the level of global temperature increase to well below 2 degrees C while pursuing efforts aligning to a global threshold objective of 1.5-degree C. Through the review of existing literature, the researchers aim to provide a better understanding of climate change and the biodiversity and ecosystem. In addition to this, the study provides various strengths and opportunities for the countries to explore soon, reducing the emission levels in the ecosystem and thus, promoting a sustainable future, through an interlinked phenomenon.

How Volcanic Aerosols Globally Inhibit Precipitation

AbstractVolcanic aerosols reduce global mean precipitation in the years after major eruptions, yet the mechanisms that produce this response have not been rigorously identified. Volcanic aerosols alter the atmosphere's energy balance, with precipitation changes being one pathway by which the atmosphere acts to return toward equilibrium. By examining the atmosphere's energy budget in climate model simulations using radiative kernels, we explain the global precipitation reduction as largely a consequence of Earth's surface cooling in response to volcanic aerosols reflecting incoming sunlight. These aerosols also directly add energy to the atmosphere by absorbing outgoing longwave radiation, which is a major cause of precipitation decline in the first post‐eruption year. We additionally identify factors limiting the post‐eruption precipitation decline, and provide evidence that our results are robust across climate models.

The roots of carbon emission differences between China and USA: A quantitative study based on global value chains

China and the USA, as preeminent contributors to global carbon emissions, demonstrate discernible differentials in both magnitude and trajectories of their respective carbon outputs. This article employed two methods, Structural Decomposition Analysis (SDA) and Quantitative Structural Modeling, to scrutinize the underpinnings of these disparities through the lens of the global value chain. Drawing upon data from the World Input-Output Database (WIOD), our analysis revealed that the compounded influences of output composition, input intensity, input composition and input origin collectively elevated China's aggregate carbon footprint from 2000 to 2014, while the scale effect made China's carbon emissions lower than of the USA. Notably, China's carbon emissions surpassed those of USA, with the gap accentuating over time. The quantitative results of the structural model showed that the difference in carbon emissions between China and USA predominantly stem from disparities in productivity, production technology, factor intensity, factor endowment and direct carbon intensity. Differences in trade costs exhibited some discernible impact, their influence remains relatively marginal, whereas distinctions in consumption behaviors and trade imbalances minimally contribute to the observed differentials. These findings have important policy implications for global carbon reduction efforts and China's trajectory towards a low-carbon economic paradigm.