Source Of Carbon Dioxide Research Articles

Spatial distribution of CO2 Impact on the indoor air quality of classrooms within a University

Indoor air quality (IAQ) remains a public and global concern. While CO2 does not pose health risks to occupants, high CO2 levels indicate insufficient ventilation, potentially accumulating pollutant concentrations. In buildings, occupants are identified as the main source of indoor carbon dioxide (CO2) through exhalation. Standard classrooms may have occupant density between 1.8 and 2.4m2/person. Therefore, the IAQ of classrooms and lecture theatres remain a concern. This study investigated airflow and contaminant (using CO2 as a proxy) distribution in two classrooms modelled using CFX a Computational Fluid Dynamics (CFD) software, verified against experimental measurements. The model provides the visualization of flow patterns so that the effects of external and internal flow fields in the classroom can be studied. The results show that there are large differences in classroom indoor ventilation performance due to the effects of wind direction and wind speed on building surface wind pressure from outdoor wind speeds. Windward high-pressure surfaces and leeward vortices created by building shading promote indoor air quality in buildings with windcatcher openings. The concentration distribution of CO in the classrooms showed an upward convergence with the thermal plume generated by the respiratory differences of the personnel and the temperature of the lighting equipment. The results of this study have important implications for improving classroom design guidelines for school buildings, especially in terms of ventilation strategies and air quality monitoring.

Spatial and temporal patterns of fuelwood consumption and its associated CO2 emissions in Muzaffarabad division, a western Himalayan region

BackgroundIn the Himalayan region, fuelwood serves as a critical energy source for rural communities. Being vital for meeting energy needs, fuelwood combustion is a source of carbon dioxide (CO2) emission and, consequently, global warming, as well as deforestation and public health damage. Therefore, quantifying fuelwood consumption patterns and its associated CO2 emissions is essential to understand the environmental impact and promote sustainable resource management.MethodsThis research conducts an evaluation of fuelwood burning patterns and the associated CO2 emissions in Azad Jammu and Kashmir (AJK), situated within the western Himalayan region. The study entails an extensive survey of 24 villages representing 240 households, equally distributed between the subtropical and temperate regions, each comprising 120 households. Data collection was executed through a combination of direct queries and the weight survey method, following standard protocols.ResultsIn the study area, the mean annual fuelwood comsumption per household amounts to 24.28 ± 3.1 Mg (or 3.195 ± 1 Mg capita−1). A variance was observed between subtropical and temperate zones, with the latter exhibiting higher consumption rates. The consequential CO2 emissions were assessed as 41.88 ± 4.5 Mg per household (5.51 ± 0.6 Mg capita−1). On a daily basis, households consumed an average of 66.52 ± 6.4 kg of fuelwood (8.75 ± 1.5 kg capita−1), resulting in a daily CO2 release rate of 114.745 ± 8.6 kg (15.095 ± 2 kg capita−1). The findings unveiled seasonal variations, indicating increased fuelwood consumption and emissions during the winter season. Statistical analysis shed light on the significance of altitude and family size in shaping the patterns of fuelwood use.ConclusionsThe results revealed the importance of prioritizing forest conservation and strategically implementing sustainable practices, including reforestation, afforestation, responsible harvesting, and actively promoting sustainable fuel sources. This research highlights the vital role of well-designed policies focused on preserving ecosystems and improving energy management. Policy intervention can ensure the sustainable stewardship of local and regional forest resources.

Projecting Global Mercury Emissions and Deposition Under the Shared Socioeconomic Pathways

AbstractMercury (Hg) is a naturally occurring element that has been greatly enriched in the environment by human activities like mining and fossil fuel combustion. Despite commonalities in some carbon dioxide (CO2) and Hg emission sources, the implications of long‐range climate scenarios for anthropogenic Hg emissions have yet to be explored. Here, we present comprehensive projections of anthropogenic Hg emissions extending to the year 2300 and evaluate impacts on global atmospheric Hg deposition. Projections are based on four Shared Socioeconomic Pathways (SSPs) ranging from sustainable reductions in resource and energy intensity to rapid economic growth driven by abundant fossil fuel exploitation. There is a greater than two‐fold difference in cumulative anthropogenic Hg emissions between the lower‐bound (110 Gg) and upper‐bound (235 Gg) scenarios. Hg releases to land and water are approximately six times those of direct emissions to air (600–1,470 Gg). At their peak, anthropogenic Hg emissions reach 2,200–2,600 Mg a−1 sometime between 2010 (baseline) and 2030, depending on the SSP scenario. Coal combustion is the largest determinant of differences in Hg emissions among scenarios. Decoupling of Hg and CO2 emission sources occurs under low‐to mid‐range scenarios, though contributions from artisanal and small‐scale gold mining remain uncertain. Future Hg emissions may have lower gaseous elemental Hg (Hg0) and higher divalent Hg (HgII), resulting in a higher fraction of locally sourced Hg deposition. Projected reemissions of previously deposited anthropogenic Hg follow a similar temporal trajectory to primary emissions, amplifying the benefits of primary Hg emission reductions under the most stringent mitigation scenarios.

An experimental study on high strength self-compacting concrete inclusion of zeolite and silica fume as a potential alternative sustainable cementitious materials

One of the major sources of carbon dioxide and other greenhouse gases around the world is the cement industry. They make up 6–8 % of global warming. Therefore, by conducting this experiment, we may examine the possibility of replacing cement with different cementitious materials which include zeolite,silica fume and fly ash. These mineral additives will lessen the need for cement while enhancing the properties of the concrete that has just been hardened and also in fresh state. The objective of this experiment is to explore the impact of zeolite and silica fume on the physical and durability qualitiesof high strength, self-compacting concrete utilising nano silica that has been optimised. In the course of this study, various concrete mixtures were cast with zeolite and silica fume substituted for cement in varying amounts, and there was also a control mix for reference. These additives arereplacedcement in multiples of 5 up to 20 %. The preferred dosage as 2 % Nano silica is substituted as a regular mineral additive in all mixtures. Workability tests on the fresh qualities of concrete mixtures are conducted and the EFNARC stipulations are met by these experimental findings. All the concrete mixes' parameters, including strengths like splitting tensile and compressive were identified. Tests such as the Rapid chloride permeability test, the abrasion test, water absorption and desorption test were used to evaluate the concrete's durability.

Lakes shifted from a carbon dioxide source to a sink over past two decades in China

Lakes shifted from a carbon dioxide source to a sink over past two decades in China

The Association Between CO2 Emission and Temperature in Thailand

The important source of carbon dioxide (CO2) emission is identified to be energy usage, which the demand is gradually increasing. Currently, many people are exposed to increasing temperatures, which affects to health, environment, and quality of life. Moreover, there are many worries about its continuously increasing trend. This work is interested in studying the association between the annual CO2 emission and the annual mean temperature in Thailand. At a confidence interval of 90%, a statistically significant association between the annual CO2 emission and the annual mean temperature was observed. The appropriate predictive equation represented that the CO2 emission at 0.481 M ton increased the annual mean temperature by about 1°C. The results are useful for planning the reduction of CO2 emissions in Thailand. Fascinatingly, the largest source comes from electricity production, and the most significant energy type is finished oil. Therefore, they should be controlled as the priority. Integrated methods are considered as more efficient strategies for the CO2 crisis.

Field Comparison of Carbon Dioxide Source with Biogents Sentinel-2 and Pro Traps for Adult Aedes Mosquito Surveillance.

The BG Sentinel-2 (BGS-2) and BG-Pro traps (BGS-2 configuration) were compared for their effectiveness to collect Aedes vectors and related nuisance mosquitoes in north central Florida during 2022. Traps were baited with either dry ice pellets, pressurized carbon dioxide (CO2) gas, or the novel BG yeast-derived CO2 generator. Additionally, each trap was fitted with the BG Sweetscent lure. Sixteen species were collected including Aedes albopictus and Ae. aegypti, which accounted for about 20% of the collections. The BGS-2 collected more mosquitoes compared to the BG-Pro, but the relative percent abundance of each species to total collection from each trap type was similar. Overall mosquito abundance was significantly greater in both trap types baited with dry ice compared with the other CO2 sources. Significantly more Ae. albopictus were collected from BGS-2 traps baited with dry ice than all other CO2 and trap configurations. Lastly, we did not observe any significant differences in Ae. aegypti abundance between trap type or CO2 source.

Distribution of stable Н, О and С isotopes in natural waters in the area of the Taz oil and gas condensate field (Yamalo-Nenets autonomous region)

Relevance. The study of isotopic composition of water and dissolved substances makes it possible to determine not only their genesis, but also the fractionation processes occurring in the “water–rock–gas–organic matter” system over time, i. e. as different stages of the evolution of water composition pass through. Interest in the groundwater of the Arctic regions of Western Siberia is additionally associated with the widespread occurrence of oil deposits at the depths of formation waters and the possible influence of cryogenic metamorphization processes on composition of near-surface waters. Aim. To study and compare the isotopic composition of oxygen, hydrogen and carbon in natural waters of the Yamalo-Nenets autonomous region to identify conditional isotopic markers, as well as to be able to trace the evolution of the isotopic composition of waters along a vertical section in the area of the Taz oil and gas condensate field. Objects. Surface (river, soil and lake), underground waters of the active water exchange zone of the Yamalo-Nenets autonomous region and formation waters of oil and gas deposits of the Taz field. Methods. The study of the isotopic composition of oxygen, hydrogen, and carbon of water-dissolved carbon dioxide was carried out in the Research Equipment Sharing Center at the Institute of Geology and Mineralogy SB RAS using Isotope Ratio Mass Spectrometer FinniganTM MAT 253 equipped with H/Device and GasBench II for sample preparation. Results and conclusions. The paper introduces the data on isotopic composition of O, H and C for natural waters of the Yamalo-Nenets autonomous region. The authors have determined the characteristic trends in changes in the isotopic composition of water and dissolved carbon dioxide for various water bodies. Surface and underground waters with active water exchange in terms of isotopic composition (δD and δ18О) are infiltration. As water moves down the section, with an increase in the time of interaction of the “water–rock” system and increase in temperatures, the isotopic composition becomes significantly heavier with a slope from the GMWL to the right. The authors compiled the diagram of the evolution of water-dissolved carbon isotopic composition in the region according to the obtained and some literature data. Despite the wide range of δ13C values from –30.4 to 23.6 ‰, there are, obviously, only two sources of carbon dioxide in the region: biogenic and atmospheric, with biogenic being predominant for groundwater.

Carbon and air pollutant emissions forecast of China's cement industry from 2021 to 2035

The cement industry is a major source of carbon dioxide and air pollutant emissions. This study developed a high-resolution emission inventory for China's cement industry and forecasted emissions from 2025 to 2035. The results showed that emissions in 2020 were 251, 709, 142, and 1.35 × 106 Gg for SO2, NOx, PM2.5, and CO2, respectively. The optimal model projections for 2035 showed that fuel and clinker substitutions had the best reduction effect on SO2 and CO2, with average reduction rates of –11.42 % and –7.37 %, respectively, compared to the 2035 frozen scenario. Pollutant control measures and clinker substitution had the best emission reduction effect on NOx and PM2.5, and the average reduction rates were –26.09 % and –4.23 %, respectively, compared to the 2035 frozen scenario. These results showed that the substitution of fuel and clinker has important co-benefits for air pollutants in the cement industry.

Lotic‐SIPCO2: Adaptation of an open‐source CO2 sensor system and examination of associated emission uncertainties across a range of stream sizes and land uses

AbstractRiver networks play a crucial role in the global carbon cycle, as relevant sources of carbon dioxide (CO2) to the atmosphere. Advancements in high‐frequency monitoring in aquatic environments have enabled measurement of dissolved CO2 concentration at temporal resolutions essential for studying carbon variability and evasion from these dynamic ecosystems. Here, we describe the adaptation, deployment, and validation of an open‐source and relatively low‐cost in situ pCO2 sensor system for lotic ecosystems, the lotic‐SIPCO2. We tested the lotic‐SIPCO2 in 10 streams that spanned a range of land cover and basin size. Key system adaptations for lotic environments included prevention of biofouling, configuration for variable stage height, and reduction of headspace equilibration time. We then examined which input parameters contribute the most to uncertainty in estimating CO2 emission rates and found scaling factors related to the gas exchange velocity were the most influential when CO2 concentration was significantly above saturation. Near saturation, sensor measurement of pCO2 contributed most to uncertainty in estimating CO2 emissions. We also found high‐frequency measurements of pCO2 were not necessary to accurately estimate median emission rates given the CO2 regimes of our streams, but daily to weekly sampling was sufficient. High‐frequency measurements of pCO2 remain valuable for exploring in‐stream metabolic variability, source partitioning, and storm event dynamics. Our adaptations to the SIPCO2 offer a relatively affordable and robust means of monitoring dissolved CO2 in lotic ecosystems. Our findings demonstrate priorities and related considerations in the design of monitoring projects of dissolved CO2 and CO2 evasion dynamics more broadly.

A multi-step framework for the design of a flexible power-to-methane process

In this paper, a multi-step framework to design flexible power-to-methane processes is presented. The approach considers all crucial parts of the power-to-methane process, including the renewable energy source. The aim is to provide a design that allows for feasible operation under the fluctuating conditions induced by the renewable energy source at all times. For each part of the process, the operating windows are analyzed and optimized under different site-specific constraints, and recommendations for actions regarding the technical implementations are provided. The impact of the carbon dioxide source is scrutinized, and subsequent scheduling optimization is performed to determine necessary storage capacities. The framework is demonstrated on two carbon dioxide availability scenarios where the renewable energy source is a wind turbine coupled to a polymer exchange membrane electrolyzer that produces hydrogen, which is then converted to methane in a fixed-bed reactor. The results show that the feasible operation of the system strongly depends on the site-specific conditions. In particular, the availability of carbon dioxide impacts the flexibility of the methanation reactor. When the stochiometric ratio between hydrogen and carbon dioxide cannot be sustained, the operating window of the reactor deteriorates significantly. However, it is shown that appropriate integration and scheduling of storage capacities debottlenecks the reactor and enables the utilization of all electricity generated by the wind turbine.

Deglacial export of pre-aged terrigenous carbon to the Bay of Biscay

Abstract. The last deglaciation is the most recent relatively well-documented period of pronounced and fast climate warming, and, as such, it holds important information for our understanding of the climate system. Notably, while research into terrestrial organic carbon reservoirs has been instrumental in exploring the possible sources of atmospheric carbon dioxide during periods of rapid change, the underlying mechanisms are not fully understood. Here we investigate the mobilization of organic matter to the Bay of Biscay, located in the north-eastern Atlantic Ocean off the coasts of France and Spain. Specifically, we focus on the area that was the mouth of the Channel River during the last deglaciation, where an enhanced terrigenous input has been reported for the last glacial–interglacial transition. We conducted a comprehensive suite of biomarker analyses (e.g. n-alkanes, hopanes and n-alkanoic acids) and isotopic investigations (radiocarbon dating and δ13C measurements) on a high-resolution sedimentary archive. The present study provides the first direct evidence for the fluvial supply of immature and ancient terrestrial organic matter to the core location. Moreover, our results reveal the possibility of permafrost carbon export to the ocean, driven by processes such as deglacial warming and glacial erosion. These findings are consistent with observations from other regions characterized by present or past permafrost conditions on land, which have shown that permafrost thaw and glacial erosion can lead to carbon remobilization, potentially influencing atmospheric carbon dioxide levels.

Changes in inundation drive carbon dioxide and methane fluxes in a temperate wetland

Wetlands cycle carbon by being net sinks for carbon dioxide (CO2) and net sources of methane (CH4). Daily and seasonal temporal patterns, dissolved oxygen (DO) availability, inundation status (flooded or dry/partially flooded), water depth, and vegetation can affect the magnitude of carbon uptake or emissions, but the extent and interactive effects of these variables on carbon gas fluxes are poorly understood. We characterized the linkages between carbon fluxes and these environmental and temporal drivers at the Old Woman Creek National Estuarine Research Reserve (OWC), OH. We measured diurnal gas flux patterns in an upstream side channel (called the cove) using chamber measurements at six sites (three vegetated and three non-vegetated). We sampled hourly from 7 AM to 7 PM and monthly from July to October 2022. DO concentrations and water levels were measured monthly. Water inundation status had the most influential effect on carbon fluxes with flooded conditions supporting higher CH4 fluxes (0.39 μmol CH4 m−2 s−1; −1.23 μmol CO2 m−2 s−1) and drier conditions supporting higher CO2 fluxes (0.03 μmol CH4 m−2 s−1; 0.86 μmol CO2 m−2 s−1). When flooded, the wetland was a net CO2 sink; however, it became a source for both CH4 and CO2 when water levels were low. We compared chamber-based gas fluxes from the cove in flooded (July) and dry (August) months to fluxes measured with an eddy covariance tower whose footprint covers flooded portions of the wetland. The diurnal pattern of carbon fluxes at the tower did not vary with changing water levels but remained a CO2 sink and a CH4 source even when the cove where we performed the chamber measurements dried out. These results emphasize the role of inundation status on wetland carbon cycling and highlight the importance of fluctuating hydrologic patterns, especially hydrologic drawdowns, under changing climatic conditions.

Satellite derived trends and variability of CO2 concentrations in the Middle East during 2014–2023

The Middle East has major sources of anthropogenic carbon dioxide (CO2) emissions, but a dearth of ground-based measurements precludes an investigation of its regional and temporal variability. This is achieved in this work with satellite-derived estimates from the Orbiting Carbon Observatory-2 (OCO-2) and OCO-3 missions from September 2014 to February 2023. The annual maximum and minimum column (XCO2) concentrations are generally reached in spring and autumn, respectively, with a typical seasonal cycle amplitude of 3–8 ± 0.5 ppmv in the Arabian Peninsula rising to 8–10 ± 1 ppmv in the mid-latitudes. A comparison of the seasonal-mean XCO2 values with the CO2 emissions estimated using the divergence method stresses the role played by the sources and transport of CO2 in the spatial distribution of XCO2, with anthropogenic emissions prevailing in arid and semi-arid regions that lack persistent vegetation. In the 8-year period 2015–2022, the XCO2 concentration in the United Arab Emirates (UAE) increased at a rate of about 2.50 ± 0.04 ppmv/year, with the trend empirical orthogonal function technique revealing a hotspot over northeastern UAE and southern Iran in the summer where anthropogenic emissions peak and accumulate aided by low-level wind convergence. A comparison of the satellite-derived CO2 concentration with that used to drive climate change models for different emission scenarios in the 8-year period revealed that the concentrations used in the latter is overestimated, with maximum differences exceeding 10 ppmv by 2022. This excess in the amount of CO2 can lead to an over-prediction of the projected increase in temperature in the region, an aspect that needs to be investigated further. This work stresses the need for a ground-based observational network of greenhouse gas concentrations in the Middle East to better understand its spatial and temporal variability and for the evaluation of remote sensing observations as well as climate models.

Driving Forces and Mitigation Potential of CO2 Emissions for Ship Transportation in Guangdong Province, China

Ships are important sources of carbon dioxide (CO2) emissions in Guangdong Province. The study of historical evolutions, drivers, and projected pathways of CO2 emissions can provide scientific support for the development of carbon peaking and carbon neutral strategies in Guangdong Province. The emission factor method, log-average index (LMDI) method, and scenario analysis method were adopted to estimate CO2 emissions, identify the drivers, and explore the mitigation potential from ships in Guangdong Province, separately. The results showed that:① CO2 emissions from ships in Guangdong Province increased from 3.319 4 million tons to 6.392 9 million tons from 2006 to 2020, with dry bulk carriers and container ships being the main ship types causing the increase in emissions. ② The positive drivers of CO2 emissions from ships in Guangdong Province from 2006 to 2020 were transport intensity (51%) and economic factors (49%), and the negative drivers were energy intensity (93%) and cargo class structure (7%). ③ Carbon peaking would not be reached by 2030 if Guangdong Province maintains the current policy (baseline scenario) for ship transportation. ④ Simultaneous optimization of the energy structure and promotion of the energy intensity (energy-efficient and low-carbon scenario) had a 56.51% potential to reduce CO2 emissions from ships compared to the baseline scenario. This can provide scientific support for Guangdong Province to develop a carbon peaking and carbon neutral control strategy for the shipping industry.

Conventional and renewable energy sources and the carbon footprint

It is accepted that energy is among the main, if not the most important, anthropogenic source of carbon dioxide (CO2) emissions. It is for this reason that many efforts are aimed at finding alternative, non-CO2-emitting energy sources. For several decades, large-scale projects have been invested in the construction of solar and wind power plants, which are claimed to be the most environmentally friendly way to obtain energy. Today, the European Green Deal and international climate policy are currently among most actual topical political and economic topics. How true is this and is this energy capable of solving the “greenhouse effect” problem? Is it capable of meeting our needs for reliable, consistent and cheap energy? Is the “greenhouse effect” caused by human activity at all? These are questions that this article seeks to answer. I am well aware that I am going to violate the purportedly consensual, common understanding of these matters I am also aware of the existence of certain, albeit unwritten, limitations in expressing opinions on these issues. But I am convinced that science is a sequence of stated hypotheses, their denial, challenge, improvement, modification and so on. That is, science is not a place for searching for consensus, but for a productive dispute leading to the correct conclusions.

Improving indoor air quality and thermal comfort using a total heat exchanger ventilation system for an office building

Indoor air quality (IAQ) and thermal comfort affect occupant comfort and productivity. Thermal comfort supports productivity, while IAQ maintains occupant health. However, occupants are the main source of carbon dioxide, which is the main index for indoor pollutants in educational buildings due to many occupants gathering in one room. This study investigates the performance of applying a total heat exchanger (THX) for diluting carbon dioxide (CO2). Besides, the thermal comfort of the occupants has been evaluated extensively as the THX also reduces the fresh air temperature. An office area with 14 graduate students seated in a meeting was investigated. Questionnaires and field measurements were conducted simultaneously. Time-varying IAQ (carbon dioxide concentration) was assessed using computational fluid dynamics. The numerical simulation program also contained User Defined Function (UDF) based predicted mean vote (PMV) algorithms to determine occupant thermal comfort. The results indicated that without using THX, the CO2 concentration gradually rises until it reaches a maximum of 1400 ppm inside the room. This condition occurs because there is no air change between indoor and fresh air, mainly due to the lack of fresh air supply and reliance on split AC for circulation. With THX, the concentration could lower to below 1000 ppm. In addition, it also could make room temperature slightly lower, with the overall temperature average in this study being 24.5?C without THX and 24.1?C when THX is operated.

Composting off-gas as alternative source of carbon dioxide for spirulina cultivation – a preliminary study

Composting off-gas as alternative source of carbon dioxide for spirulina cultivation – a preliminary study

ПИЛОТНЫЙ КАРБОНОВЫЙ ПОЛИГОН: АНАЛИЗ ЗАПАСОВ УГЛЕРОДА В ПОЧВАХ СЕЛЬХОЗУГОДИЙ

The carbon cycle in agroecosystems is determined by the balance between the absorption of carbon dioxide by terrestrial vegetation of agricultural crops to create organic matter and its release during soil respiration. The soil cover is a powerful source of carbon dioxide and serves as a reservoir accumulating soil organic carbon. Organic carbon accumulating in the humus of soils serves as a drain of carbon dioxide, methane into the atmosphere for hundreds of years. The research was carried out in order to analyze the reserves of organic carbon in the soils of agroecosystems and assess the emission of CO2 and CH4 gases. The work was carried out in 2022-2023 at the site of a pilot carbon landfill (arable land) in the Republic of Bashkortostan. In field and laboratory experiments, technologies for controlling carbon dioxide emissions on agricultural lands were developed and tested. In the field, full-profile soil sections and digs were laid in accordance with GOST R58595-2019 with the determination of morphological properties and the selection of soil samples for laboratory analysis. Agrochemical analysis of the soil for the content of organic matter, the density of addition, the content of mobile phosphorus and potassium, the pH value allowed us to estimate the carbon stock of the soil of the carbon landfill according to the methodology of the Ministry of Natural Resources of the Russian Federation. The total reserves of organic carbon of the arable horizon at the carbon-new landfill amount to 503.8 t/ha, which vary and depend on the employment of the field and the characteristics of the agricultural crop. Measurement of the destructive part of the carbon cycle using a portable LI-COR 7810 camera showed that the fields occupied by crops differ in the intensity of the release of soil carbon dioxide ‒ in the field under pure steam, CO2 emissions were 2.18 times lower than under perennial grasses. The availability of data on the spatial distribution of organic soil carbon makes it possible to introduce carbon-dependent crop rotations with a set of crops that contribute to the maximum absorption of atmospheric CO2 and other greenhouse gases into the practice of agriculture.

Temperature response of soil respiration decreases with latitude and elevation in abandoned croplands

Soil respiration (Rs), a critical component of the global carbon cycle, is highly sensitive to warming. Agricultural soils, including abandoned croplands, are large sources of carbon dioxide to the atmosphere. However, the responses of Rs and its components to warming from abandoned croplands with no further management activities remain elusive at the national scale. Here, we report the warming responses of Rs, heterotrophic respiration (Rh), and autotrophic respiration (Ra) from China’s abandoned croplands spanning a large range in latitude (22.33–46.58°N) and elevation (2–3734 m) from three-year in situ warming experiments. We found that warming treatment (+1.6 °C) significantly stimulated Rs, Rh, and Ra by 30.4%, 37.2%, and 37.3%, respectively. The response of Rs to warming was higher in abandoned croplands (19.1% °C−1) than in other terrestrial ecosystems (5.4%–9.2% °C−1), attributing to greater increases in plant biomass and soil organic carbon induced by warming. Rs was more responsive to warming in low latitude or elevation regions with high plant biomass. Under the warming conditions, the apparent temperature sensitivity (Q10) of Rs increased in low latitude and elevation regions due to a decrease in soil carbon availability but decreased in high latitude and elevation regions due to an increase in carbon availability induced by warming. Despite the positive warming response of Rs, the net ecosystem productivity in abandoned croplands slightly increased by 18.7% attributing to increased plant productivity under warming. These findings demonstrate that Rs in abandoned croplands was more sensitive to warming in warmer regions than in colder regions, underscoring the importance of latitude- or elevation-induced variations in soil carbon availability in determining the response of Rs to warming and projecting cropland carbon-climate feedback.