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1.
Reducing carbon intensity (CI) is one of the core steps of climate change mitigation. This study emphasized the roles of ecological services and regional heterogeneity in determining CI. We considered heterogeneities based on geography and income and explored the roles of net primary productivity (NPP)-based carbon footprint and CI in the changes in China's CI over 2001−2015 using an extended production-theoretical decomposition analysis and matching the socio-economic data sets with NPP data from a remote sensing satellite. We found that group technological change, reflecting the effect of shrinkage or expansion of the group best practice frontier, and the potential NPP-based carbon footprint, reflecting the impact of energy-related CO2 emissions on ecological carbon absorption, are the most significant factors accounting for the increase and decrease in CI, respectively, while NPP-based CI generally accounts for the decline in CI. We further showed that the technology gap change exhibited by an invert U-shaped curve contributed to the increase in CI under geography-based heterogeneity. We advise that China's policies should be more focused on ecological factors and regional heterogeneity in regions with abundant NPP (e.g., Yunnan and Sichuan) to further reduce CI.  相似文献   

2.
At least 88 new hydropower dams are planned between 2010 and 2030 in the lower Mekong River basin in Southeast Asia as a source of electricity with lower greenhouse gas emissions. Dams result in declines in fish populations that will need to be replaced with other sources of protein for food security. We make the first assessment of emissions should beef production substitute for lost fish in Cambodia and Laos. We assessed two sources of emissions. Replacing lost fish with beef would require as much as 12 million hectares of new pasture. Forest clearing for pastures in Cambodia and Lao PDR would initially emit between 0.859 and 3.015 giga‐tonnes of carbon dioxide equivalents (Gt CO2‐eq.). Methane emissions from additional cattle would add at least 0.0013 Gt CO2‐eq./year to Cambodia's total greenhouse gas emissions, equivalent to a 20% increase. In Laos at least 0.0005 Gt CO2‐eq./year would be released, a 4–12% increase in annual emissions. We demonstrate that activities displaced by hydropower developments could significantly increase emissions. It shows how enclosure of commons at local scales impacts upon other common pool resources at different scales, raising questions for sustainable and equitable transboundary governance.  相似文献   

3.
This paper examines the impact of China's export trade on smog pollution. Based on provincial panel data from 2006 to 2016 in China, we use spatial econometric methods to empirically investigate the smog pollution effects of China's export trade from two dimensions, export scale and export structure. It has been found that smog pollution in various regions of China has obvious spatial correlation; China's export trade has a significant positive impact on smog pollution, whether in terms of export scale or export structure. After establishing different forms of spatial weight matrices and considering alternative indicators of smog pollution, the results of this paper are still robust.  相似文献   

4.
基于低碳经济视角下首都新农村可持续发展的研究   总被引:7,自引:0,他引:7  
“低碳经济”的概念首先是由英国在《我们未来的能源——创建低碳经济》的白皮书中提出的,其目标是减缓气候变化和促进人类的可持续发展。低碳农业经济能够减少农业排放大量温室气体,应对气候变化对农业的威胁,并实现首都新农村可持续发展。笔者从低碳产业、低碳农业、低碳工业、低碳环境、碳汇减碳五个方面提出低碳农业经济在首都新农村可持续的发展思路。  相似文献   

5.
Abstract: Will future transportation carbon dioxide (CO2) emissions per capita in Asia Pacific economies follow historical trends of the now developed world? Evidence to date is inconclusive. A comparison at similar income levels (purchasing power parity) between recent emissions in Asia Pacific countries and historical emissions in developed countries suggests diverging patterns. (A) High‐income Asia economies (Japan, Hong Kong and Singapore –‘low emitters’) exhibit lower emissions than a selected sample of seven developed countries (United States, Australia, France, the Netherlands, Italy, Sweden and United Kingdom). (B) Another set of Asian countries (South Korea and Taiwan –‘medium emitters’) follow the emissions trends of European countries, which are lower than those of Australia and the United States. (C) A third Asian group (Malaysia and Thailand –‘high emitters’) exhibit emission trends comparable to that of Australia. We describe these trends, examine their causes and extrapolate likely futures for emissions in low‐income Asia Pacific economies (China, Indonesia, Philippines and Vietnam). Although such predictions are speculative, the available evidence suggests that road CO2 emissions for Indonesia, the Philippines and Vietnam will follow those of the third group (high emitters), while those for China may follow either Group B or Group C.  相似文献   

6.
Anthropogenic increases in atmospheric carbon dioxide concentration [CO2], and subsequent increases in surface temperatures, are likely to impact the growth and yield of cereal crops. One potential means for yield reduction is for climate parameters to increase the occurrence of lodging. Using an in situ free-air CO2 enrichment (FACE) system, two morphologically distinct rice cultivars, KH (Koshihikari) and SY (Shan you 63), were grown at two [CO2]s (ambient and ambient + 200 μmol mol−1) and two soil temperatures (ambient and ambient ± 1.8 °C) over a two year period to assess and quantify lodging risk. Elevated [CO2] per se had no effect on lodging resistance for either cultivar. However, elevated [CO2] and higher soil temperature increased the lodging risk for SY, due to a relatively higher increase in plant biomass and height at the elevated, relative to the ambient [CO2] condition. Elevated soil temperature per se also increased lodging risk for both cultivars and was associated with longer internodes in the lower portion of the tillers. These findings illustrate that lodging susceptibility in rice, an important cereal crop, can be increased by rising [CO2] and soil temperature; however, variation observed here between rice cultivars suggests there may be sufficient intraspecific variability to begin choosing rice lines that minimize the potential risk of lodging.  相似文献   

7.
干旱地区农田生态系统土壤温室气体排放机制   总被引:3,自引:0,他引:3  
CO2、CH4和N2O是目前几种最主要的温室气体,在对全球气候变暖贡献中,农业作为重要的温室气体排放源对其有不可低估的作用。一般而言,旱地农田生态系统是大气CO2和N2O的排放源,黄土高原等旱地是CH4的吸收汇。CO2排放主要包括植物呼吸作用和土壤呼吸作用;CH4排放包括有机物的还原和氧化吸收两个过程;N2O排放包括硝化作用和反硝化作用两个过程。土壤微生物、土壤水分、土壤温度、土壤质地、施肥等均从不同角度影响着温室气体的释放与吸收。近些年,免耕、秸秆还田、地膜等保护性耕作技术在干旱地区农田生态系统中得到广泛应用。其中免耕可以减少CO2和N2O的排放量,增加土壤对CH4的吸收量;秸秆还田和覆膜对N2O排放的影响结果尚未统一,但秸秆还田促进CO2排 放抑制CH4吸收,而覆膜促进CH4吸收抑制CO2排放。加强且更深入更全面的研究旱地农田生态系统温室气体排放应该作为今后重点研究领域,为全球气候变暖提供更为准确的理论基础。  相似文献   

8.
Increasing atmospheric CO2 is recognized as a major aspect of global climate change that would have a significant impact on the productivity of major agricultural crops. Two field experiments were done, with the objective of quantifying the response of a short‐duration rice (Oryza sativa) variety (BG‐300) to elevated atmospheric carbon dioxide, in the low elevation, subhumid zone of Sri Lanka. The experiment contained three treatments. In the elevated CO2 treatment, rice was grown at a CO2 concentration of 570 µmol/mol within open top chambers (OTC s). The ambient CO2 treatment included crops grown within OTC s, but maintained at the ambient CO2 concentration of 370 µmol/mol. The third treatment was a crop grown in the open field under ambient CO2 concentration. Grain yields of rice crops grown under elevated CO2 were 24 % and 39 % greater than the respective ambient treatments in the maha (January – March 2001) and yala (May – August, 2001) seasons. Significant increases in total biomass at harvest (23 % and 39 %, respectively, in maha and yala) were more responsible for the above yield increases than the slight increases in the harvest index (4 % and 2 %). Yields of the ambient and open field treatments did not differ significantly. Among the yield components, the number of panicles per hill was significantly higher in the elevated treatment and showed significant positive correlations with grain yield in both seasons. In addition, grain yield showed significant positive correlations with the percentage of filled grains in maha and the number of grains per panicle in yala. Significant increases in the number of tillers per hill under elevated CO2 were responsible for its greater leaf area index and the greater numbers of panicles per hill. Crops under elevated CO2 accumulated biomass faster than those grown under ambient CO2 during the vegetative and grain‐filling stages. The results of this study demonstrate that elevated CO2 causes significant yield increases in rice, even when it is grown in warm, subhumid tropical climates.  相似文献   

9.
Reducing carbon emissions is the only way to solve the global climate problem, which obviously requires the joint efforts of all regions. From the perspective of carbon emission reduction demand, this research obtains the data of low-carbon patents and CO2 emissions from 2000 to 2019, and then explores the innovation effect of low-carbon technology transfer in the Yangtze River Economic Belt (YREB). We draw the following conclusions: (1) Low-carbon technology transfer has a positive impact on low-carbon technology innovation. However, a large number of low-carbon technology transfers are concentrated between developed regions in the YREB at present. (2) No matter from the perspective of total amount or efficiency, carbon emission reduction demand can play positive moderating role in the process of exerting the innovation effect of low-carbon technology transfer, indicating that the transfer of low-carbon technologies to regions with high demand is efficient. (3) The moderating effect of carbon emission reduction demand in different regions has regional heterogeneity. Carbon emissions per unit of GDP plays a greater role in moderating the innovation effect of low-carbon technology transfer in the eastern region, while CO2 emissions plays a greater role in the central and western regions. Therefore, we propose to strengthen the transfer of low-carbon technologies between developed and less-developed regions, and adopt differentiation strategies according to the actual situation of each region. Our research has deepened the understanding of environmental economic geography on the innovation effect of low-carbon technology transfer, and has reference significance for global low-carbon technology cooperation.  相似文献   

10.
陆地生态系统有机碳储量和碳排放的研究进展   总被引:1,自引:1,他引:0  
夏雪  车升国 《中国农学通报》2011,27(29):214-218
陆地生态系统土壤有机碳储量和土壤呼吸的微小变化,会引起大气CO2浓度的巨大变化以及全球碳循环的明显改变,从而引起全球气候的巨大变化。提高SOC储量、减少土壤CO2排放对减缓大气CO2浓度升高具有重要意义。笔者根据国内外文献数据资料,综合分析陆地生态系统土壤有机碳储量和土壤呼吸的研究进展,并对最近土壤呼吸影响因素的研究热点因子,如土壤温度、土壤水分、大气降水和耕作等进行分析讨论,指出陆地生态系统碳循环研究中应重点加强土壤呼吸的机理、土壤呼吸影响因素、土壤呼吸模型、土壤固碳措施、减排对策的研究。  相似文献   

11.
低碳农业背景下闽台有机农业交流与发展的研究   总被引:2,自引:0,他引:2  
摘要:在全球应对气候变暖而提出发展“新的工业革命”--“低碳经济”的背景下,本文在对“低碳经济”兴起和“低碳农业”原理进行阐述的基础上,提出应用“低碳农业”技术,借鉴台湾低碳农业和有机农业的发展经验,以有机农业作为发展福建低碳农业的切入点,以期促进福建有机农业的发展和加强海峡两岸农业经济的合作与交流。  相似文献   

12.
Hong Kong continues to struggle over which environmental governance approach is in its best interest while fulfilling its environmental obligations. With regard to climate change, Hong Kong's approach is characterised by a passive form of governance that is highly dependent on China's national policy directions. This is reflected, for example, in Hong Kong having not set its own mitigation targets. Market mechanisms have received little attention in developing a city‐wide climate change strategy. A transformative impulse, China's national emissions trading scheme, may provide momentum to a market‐based approach. However, the necessary conditions for such a market mechanism to be successfully implemented in China remain relatively undeveloped. This raises question about early participation by Hong Kong. Direct benefits are likely to be limited, due to Hong Kong's economic structure and weak demand for emissions reduction. Besides, there are regulatory barriers to enforcing emissions targets and/or recognising emissions allowances and credits from China. We therefore argue that nationwide emissions trading may, at this time, present more challenges than opportunities for Hong Kong to leverage its efforts on climate change mitigation. An alternative is to promote voluntary emissions trading that will require active involvement and leadership by businesses.  相似文献   

13.
中国农田减缓气候变化的潜力与技术途径   总被引:1,自引:0,他引:1  
以全球变暖为主要特征的气候变化是当前人类面临的主要环境问题之一,并且对农业生产和粮食安全产生了重大影响。增强作物对气候变化的响应与适应能力,提升农田系统固碳减排潜力,是中国农业生产上亟待解决的重要问题。笔者简要分析了国内农业固碳现状,总结了农业生产上应对气候变化的相关技术体系。通过分析国内农业生产适应和减缓气候变化的潜力和技术途径,对未来增加农业固碳潜力的研究做出了展望,为气候变化背景下实现中国农业的可持续发展提供了新的参考和借鉴。  相似文献   

14.
Increasing atmospheric carbon dioxide concentration (CO2) is an important component of global climate change that will have a significant impact on the productivity of crop plants. In recent years, growth and yield of agricultural crop plants have been shown to increase with elevated CO2 (EC) and have enticed considerable interest due to variation in the response of crop plants. In this study, comparative response of two mung bean cultivars (HUM‐2 and HUM‐6) was evaluated against EC at different growth stages under near‐natural conditions for two consecutive years. The plants were grown in ambient as well as EC (700 ppm) in specially designed open‐top chambers. Under elevated CO2, marked down‐regulation of reactive oxygen species (ROS) levels, membrane disruption and activities of superoxide dismutase and catalase were noticed in both the cultivars, but the extent of reduction was more in HUM‐6. As compared to ambient CO2, EC increased total chlorophyll, photosynthetic rate, growth and yield parameters. Cultivar‐specific response was noticed as HUM‐6 showed higher increase in yield attributes than HUM‐2. Under CO2 treatment, soluble protein and reducing sugars decreased while total soluble sugars and starch showed an opposite trend. Principal component analysis showed that both the cultivars responded more or less similarly to EC in their respective groupings of physiological and growth parameters, but the magnitude of ROS and antioxidative enzymes was variable. The experimental findings depict that both the cultivars of mung bean showed contrasting response against EC and paved the way for selecting the suitable cultivar having higher productivity in a future high‐CO2 environment.  相似文献   

15.
充分发挥茶园碳汇功能,促进茶叶低碳生产发展   总被引:1,自引:1,他引:0  
在全球气候变化已引起世界各国关注的今天,发展低碳经济,采用可持续的低碳农业技术措施发展低碳农业,是解决气候变化与经济发展矛盾的有效途径。本研究介绍了茶园碳汇功能:茶树生长对空气中CO2的固定和茶园土壤碳库对有机碳的富积和保存。总结中国茶叶生产实践和茶叶科学研究过程中形成的低碳茶叶生产技术:因地制宜合理规划、合理开垦防止烧山垦园、合理密植因缺补缺、平衡施肥促进茶树无机有机物质循环过程的进程、立体栽培增加茶园生物多样性、免耕或减耕减少土壤碳排放、增施有机肥提高土壤C/N率等;提出提高茶农对低碳的认识、建立茶叶低碳生产示范园区、加强对茶叶生产低碳技术的研究、大力发展有机茶、政府政策导向支持等促进茶叶低碳生产发展建议。采用低碳生产技术,挖掘茶园生态系统的碳汇能力,增加茶园系统碳储量,必将对减少温室气体排放做出重大贡献。  相似文献   

16.
Conservation tillage and crop rotations improve soil quality. However, the impact of these practices on greenhouse gas (GHG) emissions and crop yields is not well defined, particularly in dry climates. A rainfed 2-year field-experiment was conducted to evaluate the effect of three long-term (17–18 years) tillage systems (Conventional Tillage (CT), Minimum Tillage (MT) and No Tillage (NT)) and two cropping systems (rotational wheat (Triticum aestivum L.) preceded by fallow, and wheat in monoculture), on nitrous oxide (N2O) and methane (CH4) emissions, during two field campaigns. Soil mineral N, water-filled pore space, dissolved organic carbon (C) and grain yield were measured and yield-scaled N2O emissions, N surplus and Global Warming Potentials (GWP) were calculated. No tillage only decreased cumulative N2O losses (compared to MT/CT) during campaign 1 (the driest campaign with least fertilizer N input), while tillage did not affect CH4 oxidation. The GWP demonstrated that the enhancement of C stocks under NT caused this tillage management to decrease overall CO2 equivalent emissions. Monoculture increased N2O fluxes during campaign 2 (normal year and conventional N input) and decreased CH4 uptake, as opposed to rotational wheat. Conversely, wheat in monoculture tended to increase soil organic C stocks and therefore resulted in a lower GWP, but differences were not statistically significant. Grain yields were strongly influenced by climatic variability. The NT and CT treatments yielded most during the dry and the normal campaign, and the yield-scaled N2O emissions followed the same tendency. Minimum tillage was not an adequate tillage management considering the GWP and the yield-scaled N2O emissions (which were 39% lower in NT with respect to MT). Regarding the crop effect, wheat in rotation resulted in a 32% increase in grain yield and 31% mitigation of yield-scaled N2O emissions. Low cumulative N2O fluxes (<250 g N2O-N ha−1 campaign−1) highlighted the relevance of soil organic C and CO2 emissions from inputs and operations in rainfed semi-arid cropping systems. This study suggests that NT and crop rotation can be recommended as good agricultural practices in order to establish an optimal balance between GHGs fluxes, GWP, yield-scaled N2O emissions and N surpluses.  相似文献   

17.
【目的】随着自由贸易区战略的实施,中国的农产品出口将获得良好的发展机遇,但国内农产品市场开放的压力也将不断增加。在这种情况下,如何扬长避短、提升我国农产品的出口竞争力、最大化农产品贸易收益就变得尤为重要。【方法】从中国的农产品贸易平衡状况、农产品出口区域以及出口主体出发,分析了中国的农产品出口现状,并在此基础上,采用国际市场占有率(IMS)、显示性比较优势指数(RCA)和出口竞争力系数(CI)3个指标对我国农产品的出口竞争力进行了测算和分析。【结果】结果表明,我国的农产品总体出口竞争力相对较弱,仍需进一步提升。【结论】我国应该采取调整农业产业结构、提升农产品附加值、增强品牌效应、积极开发新兴市场等措施来进一步增强我国农产品的出口竞争力。  相似文献   

18.
A space-and-time dependent mathematical model describing perforation-mediated modified atmosphere packages was developed for respiring commodities. The model is based primarily on fundamental laws, with empirical relations used only when no other approach can be devised or when there is a significant advantage from using an empirical approach. The computational domain is divided into four subdomains: a part of the ambient storage environment; the perforation, allowing gas exchange between the package and the ambient; the commodity layer, inside the package; and the headspace above the commodity, but also contained in the package. The package walls are rigid and impermeable to gases but heat conducting. The commodity is treated as a homogenous porous medium with distributed sinks for oxygen consumption and distributed sources for carbon dioxide production due to commodity respiration. The commodity model also accounts for water vapour production due to transpiration and removal caused by possible condensation. The effects of commodity temperature and headspace gas composition on oxygen consumption and carbon dioxide production are accounted through a respiration model. The model permits the determination of the gas mixture velocity as the solution of Darcy's law in the commodity layer and the Navier–Stokes equations in the headspace, perforation, and surrounding ambient storage area. Transport of oxygen, carbon dioxide, water vapour and nitrogen is modelled based on Maxwell–Stefan equations coupled with the Navier–Stokes equations and Darcy's law. Solubility of carbon dioxide within the commodity has been included in the model. Commodity temperature and gas mixture temperature are modelled as solutions of the energy equation in the appropriate subdomains, coupled through transpiration, condensation, and convective heat transfer at the commodity surface.  相似文献   

19.
Crop models are suitable tools to assess the potential impacts of climate change on crop productivity. While the associated assessment reports have been focused on major rice production regions, there is little information on how climate change will impact the future rice crop production in mountainous highland regions. This study investigated effects of climate change on yield of paddy rice (Oryza sativa) in mountainous highland terrains of Korea using the CERES-Rice 4.0 crop model. The model was first calibrated and validated based on observed data and then applied to simulations for the future projections of rice yield in a typical mountainous terrain which borders North and South Korea, the Haean Basin in Kangwon Province, Republic of Korea. Rice yield in the highland terrain was projected to increase by 2050 and 2100 primarily due to elevated CO2 concentration. This effect of CO2 fertilization on yield (+10.9% in 2050 and +20.0% in 2100) was also responsible for increases in water-use efficiency and nitrogen-use efficiency. With management options, such as planting date shift and increasing nitrogen application, additional yield gains were predicted in response to the future climate in this area. We also found that improving genetic traits should be another option to get further yield increases. All in all, climate change in mountainous highland areas should positively influence on paddy rice productivity.  相似文献   

20.
This paper provides a broad survey of existing literature on contemporary solid waste management (SWM) in the Pacific region to underscore an urgent and compelling need for improved SWM. Despite advances in waste management systems and funding for technical support and capacity building from a range of sources, waste continues to threaten public and ecological health and the economy in Pacific Islands Countries and Territories (PICTs). SWM in the Pacific requires innovative thinking in a challenging environment of remoteness, limited available land, fragile ecosystems, vulnerability to natural hazards and subsequent climate sensitivity. Many PICTs are under considerable pressure to open their markets up to trade liberalisation. Increasing links to the global economy through trade liberalisation could either further exacerbate waste management challenges in the Pacific or contribute to environmental protection and sustainable development goals. The authors argue that if the PICTs' urgent waste management challenges are to be meaningfully addressed, the region's leaders must ensure trading partners conform to local environmental protection policies and that trade agreements align with sustainable development goals.  相似文献   

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