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1.
It is clear that developing countries will have to be part of the global mitigation effort to avoid ‘dangerous climate change’, and, indeed, many of them are already undertaking significant actions on multiple fronts to help address this problem, even if they have not yet taken on legally binding commitment under the United Nations Framework Convention on Climate Change (UNFCCC). Since the deployment of GHG-mitigating technologies is already a significant part of this effort and likely to be even more so in the future, drawing lessons from existing programmes can help accelerate and enhance the effectiveness of this deployment process. Accordingly, this article aims to examine the deployment of wind and solar power in India, paying specific attention to the role of public policy in incentivizing and facilitating this deployment, how these policies have evolved over time, what has shaped this evolution, and what the learning has been over this period. Through this analysis, the intention is to draw out key lessons from India's experience with deployment policies and programmes in these two sectors and highlight the issues that will need to be given particular consideration in the design of future domestic policies and international cooperation programmes to enhance the move towards climate-compatible development in India. Many of these lessons should also be relevant for other developing countries that are attempting to balance their climate and developmental priorities through the deployment of renewable energy technologies.  相似文献   

2.
Grassroots innovations emerge as networks generating innovative solutions for climate change adaptation and mitigation. However, it is unclear if grassroots innovations can be successful in responding to climate change. Little evidence exists on replication, international comparisons are rare, and research tends to overlook discontinued responses in favour of successful ones. We take the Transition Movement as a case study of a rapidly spreading transnational grassroots network, and include both active and non-active local transition initiatives. We investigate the replication of grassroots innovations in different contexts with the aim to uncover general patterns of success and failure, and identify questions for future research. An online survey was carried out in 23 countries (N = 276). The data analysis entailed testing the effect of internal and contextual factors of success as drawn from the existing literature, and the identification of clusters of transition initiatives with similar internal and contextual factor configurations. Most transition initiatives consider themselves successful. Success is defined along the lines of social connectivity and empowerment, and external environmental impact. We find that less successful transition initiatives might underestimate the importance of contextual factors and material resources in influencing success. We also find that their diffusion is linked to the combination of local–global learning processes, and that there is an incubation period during which a transition initiative is consolidated. Transition initiatives seem capable of generalising organisational principles derived from unique local experiences that seem to be effective in other local contexts. However, the geographical locations matter with regard to where transition initiatives take root and the extent of their success, and ‘place attachment’ may have a role in the diffusion of successful initiatives. We suggest that longitudinal comparative studies can advance our understanding in this regard, as well as inform the changing nature of the definition of success at different stages of grassroots innovation development, and the dynamic nature of local and global linkages.  相似文献   

3.
4.
Renewable energy curtailment is a critical issue in China, impeding the country’s transition to clean energy and its ability to meet its climate goals. This paper analyzes the impacts of more flexible coal-fired power generation and improved power dispatch towards reducing wind power curtailment. A unit commitment model for power dispatch is used to conduct the analysis, with different scenarios demonstrating the relative impacts of more flexible coal-fired generation and improved power dispatch. Overall, while we find both options are effective in reducing wind power curtailment, we find that improved power dispatch is more effective: (1) the effect of ramping down coal-fired generators to reduce wind power curtailment lessens as the minimum output of coal-fired generation is decreased; and (2) as a result, at higher wind capacity levels, wind curtailment is much more significantly reduced with improved power dispatch than with decreased minimum output of coal-fired generation.

Key policy insights

  • China should emphasize both coal power flexibility and dispatch in its policies to minimize renewable power curtailment and promote clean energy transition.

  • China should accelerate the process of implementing spot market and marginal cost-based economic dispatch, while making incremental improvements to the existing equal share dispatch in places not ready for spot market.

  • A key step in improving of dispatch is incorporating renewable power forecasts into the unit commitment process and updating the daily unit commitment based on the latest forecast result.

  • China should expand the coal power flexibility retrofit programme and promote the further development of the ancillary service market to encourage more flexibility from coal-fired generation.

  相似文献   

5.
利用1987-2016年福建省沿海台风大风资料、美国NCEP再分析资料和FY2C卫星云顶亮温(TBB)资料,采用统计和天气学诊断方法,对台湾海峡西岸台风大风和极端大风进行定义并对特征进行分析。结果表明:台湾海峡西岸台风大风以7-9级为主,极端大风在10-14级,海峡西岸中部是大风重灾区。将研究时段内的台风大风样本按路径归为4类,发现产生大风的台风以登陆闽中北-浙中和登陆闽南-粤东路径居多,大风区总体位于登陆台风路径的右侧。对0608号"桑美"和1614号"莫兰蒂"产生极端大风的典型个例对比研究发现,地面北高南低形势及气压梯度越密集越有利于大风提早产生,台风上空中层冷平流侵入激发低层中尺度对流发展强盛是导致地面大风增强的可能成因。  相似文献   

6.
The case of distributed solar energy (e.g., rooftop photovoltaics) and the electricity system in the U.S. is used to develop the theory of long-term transitions in large sociotechnical systems. The study shows the advantages of analyzing sociotechnical transitions as taking place in technological fields in which advocates of different design approaches struggle for position. Over time, grassroots innovations that are connected with aspirations of local ownership tend to be displaced by better-funded models of financing supported by corporations in the financial and technology industries. The processes of blockage by the incumbents, countervailing industrial power, and incorporation and transformation (by incumbents) are developed in a field theory framework to advance the study of large technological systems in general and sustainability transitions in particular.  相似文献   

7.
A novel downscaling approach of the ERA40 (ECMWF 40-years reanalysis) data set has been taken and results for comparison with observations in Norway are shown. The method applies a nudging technique in a stretched global model, focused in the Norwegian Sea (67°N, 5°W). The effective resolution is three times the one of the ERA40, equivalent to about 30 km grid spacing in the area of focus. Longer waves (<T42) in the downscaled solution are nudged towards the ERA40 solution, and thus the large-scale circulation is similar in the two data sets. The shorter waves are free to evolve, and produce high intensities of winds and precipitation. The comparison to observations incorporate numerous station data points of (1) precipitation (#357), (2) temperature (#98) and (3) wind (#10), and for the period 1961–1990, the downscaled data set shows large improvements over ERA40. The daily precipitation shows considerable reduction in bias (from 50 to 11%), and twofold reduction at the 99.9 percentile (from −59 to −29%). The daily temperature showed a bias reduction of about a degree in most areas, and relative large RMSE reduction (from 7.5 to 5.0°C except winter). The wind comparison showed a slight improvement in bias, and significant improvements in RMSE.  相似文献   

8.
What is a low-carbon pathway? To many, it is a way of mitigating climate change. To others, it is about addressing market failure or capturing the co-benefits attached to low-carbon systems, such as jobs or improved health. To still others, it represents building adaptive capacity and resilience in the face of climate change. However, these interpretations can fail to acknowledge how pathways of low-carbon transitions can also become intertwined with processes and structures of inequality, exclusion and injustice. Using a critical lens that draws from a variety of disciplines, this article explores three ways through which responses to climate change can entrench, exacerbate or reconfigure the power of elites. As society attempts to create a low-carbon society, including for example via coastal protection efforts, disaster recovery, or climate change mitigation and renewable energy, these efforts intersect with at least three processes of elite power: experimentation, financialisation, and dispossession. Experimentation is when elites use the world as a laboratory to test or pilot low-carbon technologies or policy models, transferring risks yet not always sharing benefits. Financialisation refers to the expansion and proliferation of finance, capital, and financial markets in the global economy and many national economies, processes of which have recently extended to renewable energy. Dispossession is when elites use decarbonisation as a process through which to appropriate land, wealth, or other assets (and in the process make society more majoritarian and/or unequal). We explore these three themes using a variety of evidence across illustrative case studies, including hard and soft coastal protection measures (Bangladesh, Netherlands), climate risk insurance (Malawi), and renewable energy auctions and associated mechanisms of finance and investment (South Africa and Mexico).  相似文献   

9.
Experimentation has emerged as an important strategy of climate governance, and China, with a distinctive experiment-based policy process, is a leading example of a state-led and coordinated approach to low-carbon experimentation. Through a case study of the photovoltaics poverty alleviation (PVPA) initiative—an ambitious and experimental programme that explores the synergy between renewable energy and sustainable development by using photovoltaics to generate income for impoverished households and communities—this paper critically examines this top-down mode of experimentation from a multi-level perspective based on Heilmann's experimentation under hierarchy framework. Drawing from empirical evidence collected over two years from a PVPA pilot, we show that China's multi-level approach to experimentation requires dynamic mechanisms that enable not only the adaptation of national-level models to specific locations but also the incorporation of local implementation lessons in national policymaking. The resulting experimental governance thus extends from a combination of top-down mechanisms of control, local responses, and the broader contradictions that emerge from their interactions.  相似文献   

10.
Migration decisions are complex and are linked to multiple vulnerabilities, including changing ecological conditions precipitated by climate change. As ecological thresholds are met, community-wide migrations will become more common. These community-wide migrations are more likely to occur to already vulnerable populations, and may levy high social costs. In order to prevent the negative outcomes associated with forced migration and diaspora, policy intervention is likely. Our research examines the case study of Shishmaref, Alaska, where relocation as an adaptation strategy to changing ecological conditions is the only sustainable option. We find that the colonial history in Shishmaref is explicitly linked to contemporary exposure to hazards and increased vulnerability. We further assess obstacles to a State sponsored relocation. These obstacles include disaster response protocol that does not adequately accommodate climate change scenarios. Relocation planning is further complicated by feelings of mis- and under-representation of local voices in political arenas. This case demonstrates the interrelatedness between historically constructed vulnerability and obstacles to adaptation planning. We also offer unique insight into the details of relocation planning as an adaptation strategy among one of the first community-wide migrations associated with climate change.  相似文献   

11.
This paper describes wind-tunnel experiments on the flow around single and multiple porous windbreaks (height H), sheltering a model plant canopy (height H/3). The mean wind is normal to the windbreaks, which span the width of the wind tunnel. The incident turbulent flow simulates the adiabatic atmospheric surface layer. Five configurations are examined: single breaks of three solidities (low, medium, high; solidity = 1 - porosity), and medium-solidity multiple breaks of streamwise spacing 12H and 6H. The experimental emphases are on the interactions of the windbreak flow with the underlying plant canopy; the effects of solidity; the differences in shelter between single and multiple windbreaks; and the scaling properties of the flow. Principal results are: (1) the "quiet zones" behind each windbreak are smaller in multiple than single arrays, because of the higher turbulence level in the very rough-wall internal boundary layer which develops over the multiple arrays. Nevertheless, the overall shelter effectiveness is higher for multiple arrays than single windbreaks because of the "nonlocal shelter" induced by the array as a whole. (2) The flow approaching the windbreak decelerates above the canopy but accelerates within the canopy, particularly when the windbreak solidity is high. (3) A strong mixing layer forms just downwind of the top of each windbreak, showing some of the turbulence and scaling properties of the classical mixing layer formed between uniform, coflowing streams. (4) No dramatic increase in turbulence levels in the canopy is evident at the point where the deepening mixing layer contacts the canopy (around x/H = 3) but the characteristic inflection in the canopy wind profile is eliminated at this point.  相似文献   

12.
Involving indigenous peoples in the development of mitigation measures for climate change presents procedural, conceptual and structural challenges. Here, we reflect on some of these challenges and ways of overcoming them, as suggested by collaborative approaches to policy and decision making. We specifically focus on issues of scale, knowledge and power, and how they interrelate to act as a barrier or opportunity for the involvement of indigenous groups. We argue that multi-scalar negotiations, blended knowledge and power-sharing structures are all necessary to include indigenous communities as valuable partners in climate change mitigation, and we suggest strategies and recommendations for actively accomplishing this inclusion. Examples from recent literature about the inclusion of indigenous communities in different sectors, are used to illustrate and provide evidence of the current problematic and the need for collaborative solutions. Overall, the ideas expressed here, serve as a conceptual framework to better understand and support the inclusion of indigenous communities in policy and decision making processes.  相似文献   

13.
The occurrence of flood and drought frequency is highly correlated with the temporal fluctuations of streamflow series; understanding of these fluctuations is essential for the improved modeling and statistical prediction of extreme changes in river basins. In this study, the complexity of daily streamflow fluctuations was investigated by using multifractal detrended fluctuation analysis (MF-DFA) in a large heterogeneous lake basin, the Poyang Lake basin in China, and the potential impacts of human activities were also explored. Major results indicate that the multifractality of streamflow fluctuations shows significant regional characteristics. In the study catchment, all the daily streamflow series present a strong long-range correlation with Hurst exponents bigger than 0.8. The q-order Hurst exponent h(q) of all the hydrostations can be characterized well by only two parameters: a (0.354 ≤ a ≤ 0.384) and b (0.627 ≤ b ≤ 0.677), with no pronounced differences. Singularity spectrum analysis pointed out that small fluctuations play a dominant role in all daily streamflow series. Our research also revealed that both the correlation properties and the broad probability density function (PDF) of hydrological series can be responsible for the multifractality of streamflow series that depends on watershed areas. In addition, we emphasized the relationship between watershed area and the estimated multifractal parameters, such as the Hurst exponent and fitted parameters a and b from the q-order Hurst exponent h(q). However, the relationship between the width of the singularity spectrum (Δα) and watershed area is not clear. Further investigation revealed that increasing forest coverage and reservoir storage can effectively enhance the persistence of daily streamflow, decrease the hydrological complexity of large fluctuations, and increase the small fluctuations.  相似文献   

14.
We propose a new model to estimate daily global radiation from daily temperature range measurements. This model combines that of Majumdar et al. (Sol Energy 13(4):383–394, 1972) to estimate clear sky radiation with a Gompertz function to estimate the relation between temperature range and cloud transmittance. Model parameters are estimated from historical weather data: maximum and minimum temperatures and, if available, relative humidity; no other calibration is required. The model was parametrized and validated using 788 weather stations in Mexico. When calibrated using historical humidity data, daily global radiation was estimated with a mean root mean square error of 3.06 MJ m?2 day?1. The model performed well in all situations, except for a few stations around the Gulf of Mexico and in mountain areas. When using estimated humidity, the root mean square error of prediction was only slightly degraded (3.07 MJ m?2 day?1). Possible theoretical basis and applicability of this model to other environments are discussed.  相似文献   

15.
Snow surface and sea-ice energy budgets were measured near 87.5°N during the Arctic Summer Cloud Ocean Study (ASCOS), from August to early September 2008. Surface temperature indicated four distinct temperature regimes, characterized by varying cloud, thermodynamic and solar properties. An initial warm, melt-season regime was interrupted by a 3-day cold regime where temperatures dropped from near zero to ?7°C. Subsequently mean energy budget residuals remained small and near zero for 1 week until once again temperatures dropped rapidly and the energy budget residuals became negative. Energy budget transitions were dominated by the net radiative fluxes, largely controlled by the cloudiness. Variable heat, moisture and cloud distributions were associated with changing air-masses. Surface cloud radiative forcing, the net radiative effect of clouds on the surface relative to clear skies, is estimated. Shortwave cloud forcing ranged between ?50 W m?2 and zero and varied significantly with surface albedo, solar zenith angle and cloud liquid water. Longwave cloud forcing was larger and generally ranged between 65 and 85 W m?2, except when the cloud fraction was tenuous or contained little liquid water; thus the net effect of the clouds was to warm the surface. Both cold periods occurred under tenuous, or altogether absent, low-level clouds containing little liquid water, effectively reducing the cloud greenhouse effect. Freeze-up progression was enhanced by a combination of increasing solar zenith angles and surface albedo, while inhibited by a large, positive surface cloud forcing until a new air-mass with considerably less cloudiness advected over the experiment area.  相似文献   

16.
We evaluated two methods to estimate evapotranspiration (ETo) from minimal weather records (daily maximum and minimum temperatures) in Mexico: a modified reduced set FAO-Penman-Monteith method (Allen et al. 1998, Rome, Italy) and the Hargreaves and Samani (Appl Eng Agric 1(2): 96–99, 1985) method. In the reduced set method, the FAO-Penman-Monteith equation was applied with vapor pressure and radiation estimated from temperature data using two new models (see first and second articles in this series): mean temperature as the average of maximum and minimum temperature corrected for a constant bias and constant wind speed. The Hargreaves-Samani method combines two empirical relationships: one between diurnal temperature range ΔT and shortwave radiation Rs, and another one between average temperature and the ratio ETo/Rs: both relationships were evaluated and calibrated for Mexico. After performing a sensitivity analysis to evaluate the impact of different approximations on the estimation of Rs and ETo, several model combinations were tested to predict ETo from daily maximum and minimum temperature alone. The quality of fit of these models was evaluated on 786 weather stations covering most of the territory of Mexico. The best method was found to be a combination of the FAO-Penman-Monteith reduced set equation with the new radiation estimation and vapor pressure model. As an alternative, a recalibration of the Hargreaves-Samani equation is proposed.  相似文献   

17.
18.
In the northern Bay of Bengal, mechanisms of seasonal sea-level variation have not previously been examined, and the understanding of longer-term inter-annual sea-level variation is also not concrete. These parameters are addressed in this study utilizing available tide gauge and satellite altimetry data. The contribution of steric sea level to seasonal and longer-term inter-annual sea-level variations is quantified, and statistical analysis is performed to determine the correlations of various atmospheric and oceanic factors with sea level. This study suggests that the trend of sea-level rise in this bay (4 ± 1.33 mm/year) is higher than the global average (3.32 ± 0.46 mm/year) for the studied period 1993 to 2018. The rate of sea-level rise is higher along the coast than in the offshore area and the highest in the central part of the coast. Sea level shows a strong seasonal variation: sea level is the lowest in the winter but the highest in autumn. The contribution from the thermosteric sea level is higher to the observed sea level from winter to early summer, whereas contributions from the halosteric sea level and wind stress curl are higher during autumn. Long-term variations in sea level show strong positive correlations with thermosteric sea level, indicating that temperature is a major local controlling factor for sea-level change. In addition to local factors, long-term sea level also varies by remote forcing (equatorial zonal wind stress), which explains approximately 36 % of the sea-level variation in this bay. Sea level is low during the combined events of positive Indian Ocean dipole (IOD) and El Niño, whereas the sea level is high during the combined events of negative IOD and La Niña. This study provides an improved understanding of seasonal and longer-term inter-annual variations of sea level and the necessary groundworks for a dedicated model study to further quantify all the components of the sea-level budget in the study areas.  相似文献   

19.
This paper describes different ways of reducing urban air temperature and their results in two cities: Campinas, Brazil—a warm temperate climate with a dry winter and hot summer (Cwa), and Mendoza, Argentina—a desert climate with cold steppe (BWk). A high-resolution microclimate modeling system—ENVI-met 3.1—was used to evaluate the thermal performance of an urban canyon in each city. A total of 18 scenarios were simulated including changes in the surface albedo, vegetation percentage, and the H/W aspect ratio of the urban canyons. These results revealed the same trend in behavior for each of the combinations of strategies evaluated in both cities. Nevertheless, these strategies produce a greater temperature reduction in the warm temperate climate (Cwa). Increasing the vegetation percentage reduces air temperatures and mean radiant temperatures in all scenarios. In addition, there is a greater decrease of urban temperature with the vegetation increase when the H/W aspect ratio is lower. Also, applying low albedo on vertical surfaces and high albedo on horizontal surfaces is successful in reducing air temperatures without raising the mean radiant temperature. The best combination of strategies—60 % of vegetation, low albedos on walls and high albedos on pavements and roofs, and 1.5 H/W—could reduce air temperatures up to 6.4 °C in Campinas and 3.5 °C in Mendoza.  相似文献   

20.
Effects of time-dependent large-scale forcing, solar zenith angle, and sea surface temperature on time-mean rainfall during the Tropical Ocean Global Atmosphere Coupled Ocean?CAtmosphere Response Experiment (TOGA COARE) are examined through a partitioning analysis of a series of sensitivity cloud-resolving model experiment data based on surface rainfall budget. The model is forced by time-dependent large-scale forcing (LSF), solar zenith angle (SZA), and sea surface temperature (SST) in the control experiment and is forced only by either time-dependent LSF, SZA, or SST while others are replaced with their time averages in the sensitivity experiments. The rainfall associated with water vapor divergence and local atmospheric drying and hydrometeor loss/convergence has the largest contribution to total rainfall among eight rainfall types. The largest rainfall contribution is increased in the simulations where either time-dependent LSF, SZA, or SST is replaced with its average, whereas it is decreased in the simulation where COARE-derived large-scale vertical velocity is replaced with zero vertical velocity. The contribution of the rainfall associated with water vapor convergence to total rainfall is decreased in the simulations with time-mean LSF, SZA, and SST, whereas it is increased in the simulation without large-scale vertical velocity.  相似文献   

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