The global environmental paw print of pet food     

《Global Environmental Change》2020

Global pet ownership, especially of cats and dogs, is rising with income growth, and so too are the environmental impacts associated with their food. The global extent of these impacts has not been quantified, and existing national assessments are potentially biased due to the way in which they account for the relative impacts of constituent animal by-products (ABPs). ABPs typically have lower value than other animal products (i.e. meat, milk and eggs), but are nevertheless associated with non-negligible environmental impacts. Here we present the first global environmental impact assessment of pet food. The approach is novel in applying an economic value allocation approach to the impact of ABPs and other animal products to represent better the environmental burden. We find annual global dry pet food production is associated with 56–151 Mt CO₂ equivalent emissions (1.1%−2.9% of global agricultural emissions), 41–58 Mha agricultural land-use (0.8–1.2% of global agricultural land use) and 5–11 km³ freshwater use (0.2–0.4% of water extraction of agriculture). These impacts are equivalent to an environmental footprint of around twicethe UK land area, and would make greenhouse gas emission from pet food around the 60th highest emitting country, or equivalent to total emissions from countries such as Mozambique or the Philippines. These results indicate that rising pet food demand should be included in the broader global debate about food system sustainability.  相似文献   

飞机起降过程污染物排放对机场周边大气环境影响研究回顾与进展   总被引：1，自引：0，他引：1  

周杨  范绍佳 《气象与环境科学》2013,36(4):62-67

航空运输业的飞速发展引起了人们对飞机场污染物排放的关注。飞机污染物的排放过程主要包括起降过程和巡航过程。目前对机场飞机排放污染物的研究主要集中在飞机的起降过程（LTO循环过程）,研究手段主要为模型分析,如EDMS模型分析、SMOKE/CMAQ模型分析等,只有少量的实地采样研究。未来的研究需更细化,增加实地采样,开展定量的分析研究。  相似文献   

铁假说和HNLC海区的现场铁加富实验   总被引：3，自引：0，他引：3  

张武昌  孙松 《地球科学进展》2002,17(4):613-616

20世纪90年代,JohnMart in提出的"铁假说（ironhypothesis）"和以此为中心的海洋铁加富实验（ironenrichments）成为海洋科学领域最受瞩目的事件。"铁假说"的主要内容是：铁限制了HNLC海区中浮游生物的生产力,并进而影响了CO₂由海洋上层向深层的输出;如果在HNLC海区加入铁,就可以促进浮游植物的生长,消耗掉过剩的 N、P营养盐,加速C从海洋表层向深层输出,最终降低大气中CO₂含量,缓解温室效应。在赤道太平洋和南大洋进行的现场加富实验证明,加入铁以后,这些海区的浮游植物生物量增加,N、P等营养盐被消耗。但是,这些实验并没有降低大气中CO₂含量。铁假说只被证实了一半。  相似文献   

Analysis of model-based PM2.5 emission factors for on-road mobile sources in Mexico     

M. Zavala  H. Barrera  J. Morante  L.T. Molina 《Atmósfera》2013,26(1):109-124

This study investigates the effects of using the US-EPA MOVES2010a model for estimating PM2.5 emission factors in the Mexican vehicle fleet; the results are compared with the current PM2.5 emissions estimates in the 2005 Mexican National Emissions Inventory (MNEI). Our results show that model-based PM2.5 emissions factors updated from recent studies can have significant impacts on the estimated PM2.5 emissions from mobile sources in Mexico. Higher fractions of older vehicles tend to increase PM2.5 emissions estimates using MOVES2010a with respect to the 2005 MNEI estimates; however, the overall impact on PM emissions varies depending on the vehicle population and vehicle age composition for each Mexican state fleet. These effects are primarily driven by the higher PM2.5 emission factors from the gasoline-powered vehicles and by the high fractions of older gasoline and diesel vehicles. The results also indicate that the estimated MOVES2010a PM2.5 emission factors for Mexico were particularly sensitive to vehicle speed, ambient temperature and sulfur content, but not the relative humidity. There is a strong need to better understand the characteristics of fine particulate matter (PM) emitted from gasoline and diesel-powered vehicles in major urban areas in Mexico.  相似文献   

Review on researchesof nitrous oxide inthe Southern Oceanand relative new technologies   总被引：1，自引：0，他引：1  

Zhang Jiexia  Zhan Liyang  Chen Liqi 《地球科学进展》2013,28(11):1201-1208

Nitrous oxide is an important greenhouse gas,which has a long lifetime of about 120 years and has a 310 times greenhouse effect than CO₂. Since the industrial revolution, the atmospheric N₂O concentration has increased significantly by 20%. Ocean is a net source, about 1/3 of total oceanic souce. Southern Ocean is an important part of the global ocean system, has a unique hydrological characteristics. So far it is regarded as a significant natural source to the global N₂O flux according to the model studies. However,the field work is very limit, due to the fierce in situ conditions. The importance of N₂O reseaches of Southern Ocean, progresses of nitrous oxide researches, especially new technologies applied to underway N₂O measurements in the Southern Ocean are reviewed. The advance of field, model studies and their problems or uncertainties that need to be resolved are also discussed. The using of stable isotope methods will provide powerful tools for marine N₂O mechanism. Development of high precision monitoring technology is generally the driving force of future research. Developing techniques of laser spectroscopy in marine N₂O studies and measurment of N₂O in sea ice will provide powerful tools to differeciate the N₂O source sink characteristic, constrain their budget and formation mechanism in region such as Southern Ocean.  相似文献   

N₂O增加对大气环境影响的模拟及其与甲烷和平流层水汽影响的比较          下载免费PDF全文

毕云  许利  周任君  陈月娟  易明建  邓淑梅 《地球物理学报》2013,56(1):38-46

本文利用美国国家大气环境中心(NCAR)的二维化学、辐射和动力相互作用的模式(SOCRATES),模拟了大气中N₂O增加对O₃和温度的影响,并从化学、辐射和动力过程讨论了影响原因,此外还与大气甲烷和平流层水汽增加对大气环境的影响进行了对比.分析表明:大气中N₂O浓度增加以后,将通过化学过程引起30 km以上O₃损耗,30~40 km损耗较多;30 km以上降温明显,下平流层中低纬度地区以及对流层O₃增加并有微弱升温;30~40 km附近,北半球中高纬地区O₃减少以及降温幅度都大于南半球.对流层升温主要是N₂O和O₃增加所致,而平流层温度变化主要受O₃控制.北半球中高纬地区动力过程对温度变化的反馈较其它地区明显,这种反馈对平流层中高层北半球中高纬地区温度和O₃的变化都有明显影响.大气中甲烷增加引起的O₃损耗在45 km以上,45 km以下O₃增加.平流层水汽增加会引起40 km以上O₃减少,20~40 km大部分地区O₃增加.N₂O增加造成的O₃损耗正好位于臭氧层附近,其排放对未来O₃层恢复至关重要.N₂O增加引起下平流层15~25 km中低纬度地区有弱的升温,这与其它温室气体增加对该地区温度的影响不同,CO₂,CH₄和H₂O等增加后下平流层通常是降温.  相似文献   

全球碳排放的区域差异与收敛性分析     

张陶新 《世界地理研究》2013,(2)

本文以1992～2008年的数据为基础,采用经济增长收敛理论,分析了世界206个国家的碳排放量、人均碳排放量和碳排放强度等指标的分布特征,以及178个国家或地区指标的收敛性。研究表明：①世界各国碳排放量、人均碳排放量和碳排放强度差异很大,收入水平越高的国家其碳排放量和人均碳排放量越大;除重债穷国碳排放强度低于高收入国家外,收入水平越高的国家其碳排放强度越低。②世界碳排放强度和人均碳排放量都存在17阶段（年）的σ收敛,而世界各国碳排放量的差距在不断扩大。③全球碳排放量、人均碳排放量和碳排放强度都具有β绝对收敛性。  相似文献   

The consequences of Brazil’s lack of transport planning is written in the blood of sparrows     

Fabio Angeoletto  Deleon da Silva Leandro  Mark D. E. Fellowes 《Urban geography》2013,34(8):1191-1197

The medium-sized cities of Brazil are those with populations of between 100,000 and 500,000 inhabitants. These cities are growing rapidly, and are characterized by poor urban planning, a loss of biodiversity and decreasing health prospects for residents. Historically, urbanization in Brazil has been associated with incentives to increase the use of private vehicles for local transport. The air pollution resulting from this “car dependency” has been quantified in some major cities in Brazil, such as the megacity of São Paulo. In this paper, we demonstrate through a bioindication study carried out in the Brazilian city of Rondonópolis, that atmospheric pollution resulting from vehicular emissions is also a measurable reality for medium-sized cities. Most Brazilian cities lack air quality measurement equipment, and we used an inexpensive and easy to apply bioindication assay to measure air pollution, and this approach could be easily implemented in those cities and beyond.  相似文献   

北京城市产业碳排放的小尺度空间分布     

薛磊  李琦  刘帅 《地理研究》2013,32(7):1188-1198

基于城市乡镇街道空间单元及能源消费碳排放的定量方法基础上,计算了北京市2004和2008 年第二、三产业的二氧化碳排放量及其空间分布。结果表明：北京市第二产业的碳排放总量变化不大,空间上呈现东南高、西北低的格局;第三产业的碳排放总量则有明显的增长,空间上呈现内城区碳排放值较高、且向外围圈层扩散的趋势;第三产业中分配性服务业和生产性服务业的碳排放量较高,2008 年分配性服务业碳排放的高值区主要分布于南部的城市近郊区,生产性服务业碳排放的高值区分布于高端服务业较为集聚的区域。  相似文献   

1978-2010年福建省CO2排放及其影响因素     

李旭  范跃新  钟小剑  郭剑芬  杨智杰  杨玉盛 《亚热带资源与环境学报》2013,(1):61-67

为探明城市化进程对区域CO2排放的影响机制,本研究以中国东南沿海快速城市化地区福建省为研究区域,采用LMDI指数分解法,将福建省CO2排放分解为CO2强度效应（△CF）、能源结构效应（△CN）、经济规模效应（△CY）、能源强度效应（△Cl）和人口规模效应（△Cp）5个影响因素,探讨福建省1978--2010年期间CO2排放的驱动机制．结果表明：1978--2010年期间,福建省C02排放增加了5817．10×10^4t,年均增长率为8．87％,高于全国平均水平;推动福建省CO2排放增加的核心因素是经济规模扩张和人口增加,而抑制CO2排放增长的主要因素为能源强度的下降,能源消费结构和CO2排放强度变化不是福建省CO2排放变化的主要原因．比较不同城市化阶段发现,经济规模效应对CO2排放的促进作用逐渐增大,能源强度抑制CO2排放增长的贡献逐渐降低．  相似文献