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1.
Afforestation is considered a cost‐effective and readily available climate change mitigation option. In recent studies afforestation is presented as a major solution to limit climate change. However, estimates of afforestation potential vary widely. Moreover, the risks in global mitigation policy and the negative trade‐offs with food security are often not considered. Here we present a new approach to assess the economic potential of afforestation with the IMAGE 3.0 integrated assessment model framework. In addition, we discuss the role of afforestation in mitigation pathways and the effects of afforestation on the food system under increasingly ambitious climate targets. We show that afforestation has a mitigation potential of 4.9 GtCO2/year at 200 US$/tCO2 in 2050 leading to large‐scale application in an SSP2 scenario aiming for 2°C (410 GtCO2 cumulative up to 2100). Afforestation reduces the overall costs of mitigation policy. However, it may lead to lower mitigation ambition and lock‐in situations in other sectors. Moreover, it bears risks to implementation and permanence as the negative emissions are increasingly located in regions with high investment risks and weak governance, for example in Sub‐Saharan Africa. Afforestation also requires large amounts of land (up to 1,100 Mha) leading to large reductions in agricultural land. The increased competition for land could lead to higher food prices and an increased population at risk of hunger. Our results confirm that afforestation has substantial potential for mitigation. At the same time, we highlight that major risks and trade‐offs are involved. Pathways aiming to limit climate change to 2°C or even 1.5°C need to minimize these risks and trade‐offs in order to achieve mitigation sustainably.  相似文献   

2.
Urbanization often entails a surge in urban temperature compared to the rural surroundings: the Urban Heat Island (UHI) effect. Such a temperature increase triggers the formation of pollutants worsening the urban air quality. Jointly, bad air quality and UHI affect ecosystems and human health. To alleviate the impacts on the population and the environment, it is crucial to design effective UHI‐mitigation measures. Life Cycle Assessment (LCA) is an assessment tool able to capture the complexity of urban settlements and quantify their impact. Yet, as currently implemented, LCA neglects the interactions between the built environment and the local climate, omitting the resulting impacts. This study reviews the existing literature, showing the lack of studies that organically include interactions between the built environment and local climate in LCA. This forms the basis to identify the unsuitability of the current LCA framework for comprehensively capturing the impact of urban settlements. To overcome this limitation, this research offers a pathway to expand the LCA methodology, indicating the necessity to (a) couple the LCA methodology with climate models or physical relations that quantify the interactions between the local climate and the built environment; (b) include novel impact categories in LCA to address such interactions; and (c) use existing or ad hoc developed characterization factors to assess the impacts related to the UHI effect. The LCA community can build on the frame of reference offered by this research to overcome the current limitations of LCA and enable its use for a comprehensive assessment of the impacts of UHI and its mitigation measures.  相似文献   

3.
Most climate mitigation scenarios involve negative emissions, especially those that aim to limit global temperature increase to 2°C or less. However, the carbon uptake potential in land‐based climate change mitigation efforts is highly uncertain. Here, we address this uncertainty by using two land‐based mitigation scenarios from two land‐use models (IMAGE and MAgPIE) as input to four dynamic global vegetation models (DGVMs; LPJ‐GUESS, ORCHIDEE, JULES, LPJmL). Each of the four combinations of land‐use models and mitigation scenarios aimed for a cumulative carbon uptake of ~130 GtC by the end of the century, achieved either via the cultivation of bioenergy crops combined with carbon capture and storage (BECCS) or avoided deforestation and afforestation (ADAFF). Results suggest large uncertainty in simulated future land demand and carbon uptake rates, depending on the assumptions related to land use and land management in the models. Total cumulative carbon uptake in the DGVMs is highly variable across mitigation scenarios, ranging between 19 and 130 GtC by year 2099. Only one out of the 16 combinations of mitigation scenarios and DGVMs achieves an equivalent or higher carbon uptake than achieved in the land‐use models. The large differences in carbon uptake between the DGVMs and their discrepancy against the carbon uptake in IMAGE and MAgPIE are mainly due to different model assumptions regarding bioenergy crop yields and due to the simulation of soil carbon response to land‐use change. Differences between land‐use models and DGVMs regarding forest biomass and the rate of forest regrowth also have an impact, albeit smaller, on the results. Given the low confidence in simulated carbon uptake for a given land‐based mitigation scenario, and that negative emissions simulated by the DGVMs are typically lower than assumed in scenarios consistent with the 2°C target, relying on negative emissions to mitigate climate change is a highly uncertain strategy.  相似文献   

4.
The response of ecosystems to different magnitudes of climate warming and corresponding precipitation changes during the last few decades may provide an important reference for predicting the magnitude and trajectory of net primary productivity (NPP) in the future. In this study, a process‐based ecosystem model, Carbon Exchange between Vegetation, Soil and Atmosphere (CEVSA), was used to investigate the response of NPP to warming at both national and subregional scales during 1961–2010. The results suggest that a 1.3°C increase in temperature stimulated the positive changing trend in NPP at national scale during the past 50 years. Regardless of the magnitude of temperature increase, warming enhanced the increase in NPP; however, the positive trend of NPP decreased when warming exceeded 2°C. The largest increase in NPP was found in regions where temperature increased by 1–2°C, and this rate of increase also contributed the most to the total increase in NPP in China's terrestrial ecosystems. Decreasing precipitation depressed the positive trend in NPP that was stimulated by warming. In northern China, warming depressed the increasing trend of NPP and warming that was accompanied by decreasing precipitation led to negative changing trends in NPP in large parts of northern China, especially when warming exceeded 2°C. However, warming stimulated the increase in NPP until warming was greater than 2°C, and decreased precipitation helped to increase the NPP in southern China.  相似文献   

5.
Land‐based solutions are indispensable features of most climate mitigation scenarios. Here we conduct a novel cross‐sectoral assessment of regional carbon mitigation potential by running an ecosystem model with an explicit representation of forest structure and climate impacts for Bavaria, Germany, as a case study. We drive the model with four high‐resolution climate projections (EURO‐CORDEX) for the representative concentration pathway RCP4.5 and present‐day land‐cover from three satellite‐derived datasets (CORINE, ESA‐CCI, MODIS) and identify total mitigation potential by not only accounting for carbon storage but also material and energy substitution effects. The model represents the current state in Bavaria adequately, with a simulated forest biomass 12.9 ± 0.4% lower than data from national forest inventories. Future land‐use changes according to two ambitious land‐use harmonization scenarios (SSP1xRCP2.6, SSP4xRCP3.4) achieve a mitigation of 206 and 247 Mt C (2015–2100 period) via reforestation and the cultivation and burning of dedicated bioenergy crops, partly combined with carbon capture and storage. Sensitivity simulations suggest that converting croplands or pastures to bioenergy plantations could deliver a carbon mitigation of 40.9 and 37.7 kg C/m2, respectively, by the year 2100 if used to replace carbon‐intensive energy systems and combined with CCS. However, under less optimistic assumptions (including no CCS), only 15.3 and 12.2 kg C/m2 are mitigated and reforestation might be the better option (20.0 and 16.8 kg C/m2). Mitigation potential in existing forests is limited (converting coniferous into mixed forests, nitrogen fertilization) or even negative (suspending wood harvest) due to decreased carbon storage in product pools and associated substitution effects. Our simulations provide guidelines to policy makers, farmers, foresters, and private forest owners for sustainable and climate‐benefitting ecosystem management in temperate regions. They also emphasize the importance of the CCS technology which is regarded critically by many people, making its implementation in the short or medium term currently doubtable.  相似文献   

6.
This contribution presents the state of the art of economy‐wide material flow accounting. Starting from a brief recollection of the intellectual and policy history of this approach, we outline system definition, key methodological assumptions, and derived indicators. The next section makes an effort to establish data reliability and uncertainty for a number of existing multinational (European and global) material flow accounting (MFA) data compilations and discusses sources of inconsistencies and variations for some indicators and trends. The results show that the methodology has reached a certain maturity: Coefficients of variation between databases lie in the range of 10% to 20%, and correlations between databases across countries amount to an average R2 of 0.95. After discussing some of the research frontiers for further methodological development, we conclude that the material flow accounting framework and the data generated have reached a maturity that warrants material flow indicators to complement traditional economic and demographic information in providing a sound basis for discussing national and international policies for sustainable resource use.  相似文献   

7.
Life cycle assessment (LCA) is generally described as a tool for environmental decision making. Results from attributional LCA (ALCA), the most commonly used LCA method, often are presented in a way that suggests that policy decisions based on these results will yield the quantitative benefits estimated by ALCA. For example, ALCAs of biofuels are routinely used to suggest that the implementation of one alternative (say, a biofuel) will cause an X% change in greenhouse gas emissions, compared with a baseline (typically gasoline). However, because of several simplifications inherent in ALCA, the method, in fact, is not predictive of real‐world impacts on climate change, and hence the usual quantitative interpretation of ALCA results is not valid. A conceptually superior approach, consequential LCA (CLCA), avoids many of the limitations of ALCA, but because it is meant to model actual changes in the real world, CLCA results are scenario dependent and uncertain. These limitations mean that even the best practical CLCAs cannot produce definitive quantitative estimates of actual environmental outcomes. Both forms of LCA, however, can yield valuable insights about potential environmental effects, and CLCA can support robust decision making. By openly recognizing the limitations and understanding the appropriate uses of LCA as discussed here, practitioners and researchers can help policy makers implement policies that are less likely to have perverse effects and more likely to lead to effective environmental policies, including climate mitigation strategies.  相似文献   

8.
内蒙古草原区植被净初级生产力及其与气候的关系   总被引:12,自引:0,他引:12  
龙慧灵  李晓兵  王宏  魏丹丹  张程 《生态学报》2010,30(5):1367-1378
利用NOAA/AVHRR GIMMSNDVI数据、土地覆盖分类数据、气象数据等,基于改进的基于光能利用率的净初级生产力(Net Primary productivity,NPP)遥感估算模型对内蒙古草原区1982-2006年的NPP进行估算,并分别以年、季节和月为时间单位,计算基于像元的NPP与降水、温度之间的相关及偏相关系数,分析不同时间单位及尺度上NPP与气候的关系。结果表明,1982-2006年内蒙古草原区NPP总量呈波动增加的趋势,平均增加值为0.861Mt C/a。以年为时间单位,内蒙古草原区年NPP与降水的关系比较明显。以季节为时间单位,年际春季和夏季NPP与降水的关系比较明显,秋季二者关系相对较弱,春季和秋季NPP与温度的相关系数和偏相关系数空间格局比较一致,且相关性明显高于夏季。以月为时间单位的相关水平明显高于年际水平,多年平均年内月NPP与降水、温度的相关程度明显增强,除去降水的影响,月均温对NPP的影响明显下降,且空间格局也有明显的变化,说明以月为时间单位在年内尺度上降水对植被生长的影响比温度要大。而以4、7、10月份为例,在年际尺度上,虽然各月份NPP均受降水的影响较大,但与降水关系最为密切的是4月份和10月份NPP,与之相比,7月份NPP与温度的关系明显高于其他两月。  相似文献   

9.
The heating of buildings currently produces 6% of global greenhouse gas emissions. Sustainable heating technologies can reduce heating‐related CO2 emissions by up to 90%. We present a Python‐based GIS model to analyze the environmental and financial impact of strategies to reduce heating‐related CO2 emissions of residential buildings. The city‐wide implementation of three alternatives to natural gas are evaluated: high‐temperature heating networks, low‐temperature heating networks, and heat pumps. We find that both lowering the demand for heat and providing more sustainable sources of heat will be necessary to achieve significant CO2‐emission reductions. Of the studied alternatives, only low‐temperature heating networks and heat pumps have the potential to reduce CO2 emissions by 90%. A CO2 tax and an increase in tax on the use of natural gas are potent policy tools to accelerate the adoption of low‐carbon heating technologies.  相似文献   

10.
Changes to forest production drivers (light, water, temperature, and site nutrient) over the last 55 years have been documented in peer‐reviewed literature. The main objective of this paper is to review documented evidence of the impacts of climate change trends on forest productivity since the middle of the 20th century. We first present a concise overview of the climate controls of forest production, provide evidence of how the main controls have changed in the last 55 years, followed by a core section outlining our findings of observed and documented impacts on forest productivity and a brief discussion of the complications of interpreting trends in net primary production (NPP). At finer spatial scales, a trend is difficult to decipher, but globally, based on both satellite and ground‐based data, climatic changes seemed to have a generally positive impact on forest productivity when water was not limiting. Of the 49 papers reporting forest production levels we reviewed, 37 showed a positive growth trend, five a negative trend, three reported both a positive and a negative trend for different time periods, one reported a positive and no trend for different geographic areas, and two reported no trend. Forests occupy ≈52% of the Earth's land surface and tend to occupy more temperature and radiation‐limited environments. Less than 7% of forests are in strongly water‐limited systems. The combined and interacting effects of temperature, radiation, and precipitation changes with the positive effect of CO2, the negative effects of O3 and other pollutants, and the presently positive effects of N will not be elucidated with experimental manipulation of one or a few factors at a time. Assessments of the greening of the biosphere depend on both accurate measurements of rates (net ecosystem exchange, NPP), how much is stored at the ecosystem level (net ecosystem production) and quantification of disturbances rates on final net biome production.  相似文献   

11.
Correctly accounting for the energy and emissions embodied in consumption and trade is essential to effective climate policy design. Robust methods are needed for both policy making and research—for example, the assignment of border carbon adjustments (BCAs) and greenhouse gas emission reduction responsibilities rely on the consistency and accuracy of such estimates. This analysis investigates the potential magnitude and consequences of the error present in estimates of energy and emissions embodied in trade and consumption. To quantify the error of embodied emissions accounting, we compare the results from the disaggregated Global Trade Analysis Project (GTAP 8) data set, which contains 57 sectors to results from different levels of aggregation of this data set (3, 7, 16, and 26 sectors), using 5,000 randomly generated sectoral aggregation schemes as well as aggregations generated using several commonly applied decisions rules. We find that some commonly applied decision rules for sectoral aggregation can produce a large error. We further show that an aggregation scheme that clusters sectors according to their energy, emissions, and trade intensities (net exports over output) can minimize error in embodied energy and emissions accounting at different levels of aggregation. This sectoral aggregation scheme can be readily used in any input‐output analysis and provide useful information for computable general equilibrium modeling exercises in which sector aggregation is necessary, although our findings suggest that, when possible, the most disaggregated data available should be used.  相似文献   

12.
利用MODIS NDVI数据、气象数据和植被分类数据,基于改进的光能利用率模型CASA模型对2001-2010年内蒙古不同植被类型净初级生产力(NPP)进行估算,并分析其时空分布特征及对气候因子的响应.结果表明:(1)10年间内蒙古植被年NPP的平均值为340.0 gCm-2a-1,且空间分布呈明显的经度地带性,由西向东的变化速率为每10度增加200.5 gCm-2a-1;(2)不同植被类型NPP有较大差异,森林、草地、农田和荒漠植被的NPP平均值分别为521.9、270.3、405.7和85.3 gCm-2a-1;(3)10年间内蒙古植被NPP总量的平均值为322.7 TgCa-1,波动范围为276.8-354.4 TgCa-1.从NPP年际变化的空间分布来看,阿拉善沙漠、毛乌素沙地西部、河套平原以北地区、浑善达克沙地东西缘和呼伦贝尔平原西北部植被的NPP呈极显著上升,而内蒙古中部的草地植被NPP呈极显著下降;(4)不同植被类型NPP对气候因子的敏感性有较大差异.森林植被NPP主要受温度的限制,而农田、草地和荒漠植被NPP主要受降水量控制.  相似文献   

13.
Contemporary forest inventory data are widely used to understand environmental controls on tree species distributions and to construct models to project forest responses to climate change, but the stability and representativeness of contemporary tree‐climate relationships are poorly understood. We show that tree‐climate relationships for 15 tree genera in the upper Midwestern US have significantly altered over the last two centuries due to historical land‐use and climate change. Realised niches have shifted towards higher minimum temperatures and higher rainfall. A new attribution method implicates both historical climate change and land‐use in these shifts, with the relative importance varying among genera and climate variables. Most climate/land‐use interactions are compounding, in which historical land‐use reinforces shifts in species‐climate relationships toward wetter distributions, or confounding, in which land‐use complicates shifts towards warmer distributions. Compounding interactions imply that contemporary‐based models of species distributions may underestimate species resilience to climate change.  相似文献   

14.
The literature on climate change research has evolved tremendously since the 1990s. The goal of this study is to use text mining to review the climate change literature and study the evolution of the main trends over time. Specific keywords from articles published in the special issue “ Industrial Ecology for Climate Change Adaptation and Resilience” in the Journal of Industrial Ecology are first selected. Details of over 35,000 publications containing these keywords are downloaded from the Web of Science from 1990 to 2018. The number of publications and co‐occurrence of keywords are analyzed. Moreover, latent Dirichlet allocation (LDA)—a probabilistic approach that can retrieve topics from large and unstructured text documents—is applied on the abstracts to uncover the main topics (consisting of new terms) that naturally emerge from them. The evolution in time of the importance of some emerging topics is then analyzed on the basis of their relative frequency. Overall, a rapid growth in climate change publications is observed. Terms such as “climate change adaptation” appear on the rise, whereas other terms are declining such as “pollution.” Moreover, several terms tend to co‐occur frequently, such as “climate change adaptation” and “resilience.” The database collected and the LiTCoF (Literature Topic Co‐occurrence and Frequency) Python‐based tool developed for this study are also made openly accessible. This article met the requirements for a gold – gold JIE data openness badge described http://jie.click/badges .  相似文献   

15.
The article presents a method for the calculation of selected economy‐wide material flow indicators (namely, direct material input [DMI] and raw material input [RMI]) for economic sectors. Whereas sectoral DMI was calculated using direct data from statistics, we applied a concept of total flows and a hybrid input‐output life cycle assessment method to calculate sectoral RMI. We calculated the indicators for the Czech Republic for 2000–2011. We argue that DMI of economic sectors can be used for policies aiming at decreasing the direct input of extracted raw materials, and imported raw materials and products, whereas sectoral RMI can be better used for justifying support for or weakening the role of individual sectors within the economy. High‐input material flows are associated in the Czech Republic with the extractive industries (agriculture and forestry, the mining of fossil fuels [FFs], other types of mining, and quarrying), with several manufacturing industries (manufacturing of beverages, basic metals, motor vehicles or electricity, and gas and steam supply) and with construction. Viable options for reducing inputs of agricultural biomass include changes in people's diet toward a lower amount of animal‐based food and a decrease in the wasting of food. For FFs, one should think of changing the structure of total primary energy supply toward cleaner gaseous and renewable energy sources, innovations in transportation systems, and improvements in overall energy efficiency. For metal ores, viable options include technological changes leading to smaller and lighter products, as well as consistent recycling and use of secondary metals.  相似文献   

16.
Representing the greenhouse gas (GHG) emissions attributable to plug‐in electric vehicles (PEV) in vehicle GHG emissions regulations is complex because of spatial and temporal variation in fueling sources and vehicle use. Previous work has shown that the environmental performance of PEVs significantly varies depending on the characteristics of the electricity grid and how the vehicle is driven. This article evaluates the U.S. Environmental Protection Agency's (EPA's) GHG emissions accounting methodology in current and future standards for new electrified vehicles. The current approach employed by the EPA in their 2017–2025 model year light‐duty vehicle GHG regulation is compared with an accounting mechanism where the actual regional sales of PEVs, and the regional electricity emission factor in the year sold, are used to determine vehicle compliance value. Changes to the electricity grid over time and regional vehicle sales are included in the modeling efforts. A projection of a future GHG regulation past the 2017–2025 rule is used to observe the effect of such a regional regulation. The results showed that the complexity involved in tracking and accounting for regional PEV sales will not dramatically increase the effectiveness of the regulations to capture PEV electricity‐related GHG emissions in the absence of a major policy shift. A discussion of the feasibility and effectiveness of a regional standard for PEVs, and notable examples of region‐specific regulations instated in past energy policies, is also addressed.  相似文献   

17.
Large‐scale biomass plantations (BPs) are a common factor in climate mitigation scenarios as they promise double benefits: extracting carbon from the atmosphere and providing a renewable energy source. However, their terrestrial carbon dioxide removal (tCDR) potentials depend on important factors such as land availability, efficiency of capturing biomass‐derived carbon and the timing of operation. Land availability is restricted by the demands of future food production depending on yield increases and population growth, by requirements for nature conservation and, with respect to climate mitigation, avoiding unfavourable albedo changes. We integrate these factors in one spatially explicit biogeochemical simulation framework to explore the tCDR opportunity space on land available after these constraints are taken into account, starting either in 2020 or 2050, and lasting until 2100. We find that assumed future needs for nature protection and food production strongly limit tCDR potentials. BPs on abandoned crop and pasture areas (~1,300 Mha in scenarios of either 8.0 billion people and yield gap reductions of 25% until 2020 or 9.5 billion people and yield gap reductions of 50% until 2050) could, theoretically, sequester ~100 GtC in land carbon stocks and biomass harvest by 2100. However, this potential would be ~80% lower if only cropland was available or ~50% lower if albedo decreases were considered as a factor restricting land availability. Converting instead natural forest, shrubland or grassland into BPs could result in much larger tCDR potentials ? but at high environmental costs (e.g. biodiversity loss). The most promising avenue for effective tCDR seems to be improvement of efficient carbon utilization pathways, changes in dietary trends or the restoration of marginal lands for the implementation of tCDR.  相似文献   

18.
Governments estimate the social and economic impacts of crime, but its environmental impact is largely unacknowledged. Our study addresses this by estimating the carbon footprint of crime in England and Wales and identifies the largest sources of emissions. By applying environmentally extended input‐output analysis–derived carbon emission factors to the monetized costs of crime, we estimate that crime committed in 2011 in England and Wales gave rise to over 4 million tonnes of carbon dioxide equivalents. Burglary resulted in the largest proportion of the total footprint (30%), because of the carbon associated with replacing stolen/damaged goods. Emissions arising from criminal justice system services also accounted for a large proportion (21% of all offenses; 49% of police recorded offenses). Focus on these offenses and the carbon efficiency of these services may help reduce the overall emissions that result from crime. However, cutting crime does not automatically result in a net reduction in carbon, given that we need to take account of potential rebound effects. As an example, we consider the impact of reducing domestic burglary by 5%. Calculating this is inherently uncertain given that it depends on assumptions concerning how money would be spent in the absence of crime. We find the most likely rebound effect (our medium estimate) is an increase in emissions of 2%. Despite this uncertainty concerning carbon savings, our study goes some way toward informing policy makers of the scale of the environmental consequences of crime and thus enables it to be taken into account in policy appraisals.  相似文献   

19.
20.
The economic reform “??i M?i” in 1986 has rapidly increased the number of craft villages in Vietnam, especially in the Red River Delta (RRD) leading to environmental degradation. This article presents an assessment of environmental and resource issues of agro‐Food Processing Craft Villages (FPCVs) in RRD using a refined approach to material flow analysis focusing on consistent quantification of uncertainty with particular attention to secondary and empirical data that are often faced in material flow analyses in transition economies. Material flows of agro‐Food Processing including eight types of production were examined and linked to activities of private Households, Rice Cultivation, and Pig Farming in a model called Red River Delta. Materials investigated were Goods (i.e., total materials), organic carbon (org.C), nitrogen (N), and phosphorus (P). The findings reveal material cycles are almost entirely open, that is, the materials used in FPCVs do not recycle within the region. From ~10.5 million tons/year of imported Goods used for agro‐Food Processing, final products and utilized materials account for minor fractions (~5%, by weight). Conversely, the majority (88%) is directly discharged. Materials accumulated as stocks represent 1% of Goods (100,000 tons/year), 21% of org.C (~34,000 tons/year), 42% of N (~1,300 tons/year), and 57% of P (~300 tons/year), whose substance concentrations vastly exceed natural resilience capacities. Although agro‐Food Processing accounts for negligible material shares in Red River Delta, FPCVs pollution is severe at local levels due to the location of home‐based production. Several options for closing material loops at various system scales are recommended for environmental and resource management of FPCVs. The material flow analysis results provide a database that may be used as a decision support tool for production establishments in craft villages and relevant authorities in setting priorities on environmental planning and resource management. This article met the requirements for a gold – silver JIE data openness badge described at http://jie.click/badges .  相似文献   

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