中国气温的降尺度研究

Monthly mean temperatures at 562 stations in China are estimated using a statistical downscaling technique. The technique used is multiple linear regressions （MLRs） of principal components （PCs）. A stepwise screening procedure is used for selecting the skilful PCs as predictors used in the regression equation. The predictors include temperature at 850 hPa （7）, the combination of sea-level pressure and temperature at 850 hPa （P＋T） and the combination of geo-potential height and temperature at 850 hPa （H＋T）. The downscaling procedure is tested with the three predictors over three predictor domains. The optimum statistical model is obtained for each station and month by finding the predictor and predictor domain corresponding to the highest correlation. Finally, the optimum statistical downscaling models are applied to the Hadley Centre Coupled Model, version 3 （HadCM3） outputs under the Special Report on Emission Scenarios （SRES） A2 and B2 scenarios to construct local future temperature change scenarios for each station and month, The results show that （1） statistical downscaling produces less warming than the HadCM3 output itself; （2） the downscaled annual cycles of temperature differ from the HadCM3 output, but are similar to the observation; （3） the downscaled temperature scenarios show more warming in the north than in the south; （4） the downscaled temperature scenarios vary with emission scenarios, and the A2 scenario produces more warming than the B2, especially in the north of China.     

Emission characteristic of ozone related trace gases at a semi-urban site in the Indo-Gangetic plain using inter-correlations

Measurements of surface O₃, CO, NO_x and light NMHCs were made during December 2004 at Hissar, a semi-urban site in the state of Haryana in north-west region of the Indo-Gangetic Plain (IGP). The night-time O₃ values were higher when levels of CO, NO and NO₂ were lower but almost zero values were observed during the episodes of elevated mixing ratios of CO (above 2000 ppbv) and NO_x (above 50 ppbv). Slopes derived from linear fits of O₃ versus CO and O₃ versus NO_x scatter plots were also negative. However, elevated levels of O₃ were observed when CO and NO_x were in the range of 200–300 ppbv and 20–30 ppbv, respectively. Slope of CO-NO_x of about 33 ppbv/ppbv is much larger than that observed in the US and Europe indicating significant impact of incomplete combustion processes emitting higher CO and lesser NO_x. Correlations and ratios of these trace gases including NMHCs show dominance of recently emitted pollutants mostly from biomass burning at this site.     

中国北方未来50年土地利用变化模拟

1 IntroductionLand use m odelling is a useful tool to analyze the land use cause, process and result, torecognize the im pact of land use system change on ecological environm ent,and to support theland use planning and policy (IIA SA ,1998;Costanza etal.,…     

Comparison between numerical and analytical solution of solute transport models

The fate and movement of dissolved substances in soils and groundwater has generated considerable concern for the quality of the subsurface environment. Many analytical solutions for the partial differential equations that describe solute and pollutant movement exist. Numerical solutions are more general, and often more difficult to verify. In order to determine the model error, the examination of the ability of numerical methods compared to analytical methods is strongly recommended. The objective of the study is to make a comparison between numerical and analytical solution models for solute transport equation. In this study, the numerical solution calculated with the WAVE-model is compared with the analytical solution calculated with CXTFTT-model. The study scenarios considered variables such as compartment depth, applied flux at the top and soil dispersivity under steady-state conditions. The simulations depend on 27 solute infiltration scenarios. The solute concentrations were calculated with the WAVE-model and the CXTFIT-model for each scenario. The WAVE-model error was evaluated with three methods: absolute average maximum error, relative average maximum error and relative average area error. The study implied that the WAVE-model error increased with the increase of the compartment depth, decreasing soil dispersivity, and decrease in flux. The study leads to the recommendation to use compartment depth as thin as possible to minimise the WAVE-model error. Furthermore, it is more useful to use several numerical solution models, such as SWMS-2D model, to evaluate and examine the WAVE-model.     

县域土地持续利用情景分析

以河北省曲周县为例，根据农户调查数据以及黄淮海平原多年的试区试验研究，应用投入产出分析方法，分别计算了现状和可能替代技术条件下土地利用系统的投入产出技术系数；以纯收入为目标函数，以土地、水资源和其它自然、经济、环境条件为约束条件，用线性规划方法构建了不同技术策略下的土地持续利用情景，用LINDO软件求解后，对不同的土地利用情景进行了分析和评价。     

Convergence or divergence?: Status and prospects for US climate strategy

The objective of this paper is to assess recent developments and prospects for future changes in United States (US) climate strategy. In doing so, the paper explores some of the key factors that have shaped strategies and policies to date, distinguishing between factors related to institutional and governance structures, linkages between science and policy, energy technology and the role of interest groups. Against this background, the paper attempts to explore future development paths for US climate policy. More specifically, the paper assesses opportunities for policy changes compared to the preferences of the current administration, and the prospects for future linkages between US and international climate change strategies. In brief, the paper argues that substantial changes are unlikely to take place in the near to medium term, leaving open, however, the possibility of wide-ranging changes in domestic politics or major incidents that could facilitate a shift in the perceived need for near-term action.     

Biophysical impacts of climate change on some terrestrial ecosystems in Estonia

Climate warming due to the enhanced greenhouse effect is expected to have a significant impact on the natural environment and human activity in high latitudes. Because of its geography, wide coastal areas, water resources, forests, and wetlands, the environment of Estonia is sensitive to climate change and sea level rise. Climate change scenarios for Estonia were generated using a Model for the Assessment of Greenhouse-gas Induced Climate Change (MAGICC) and a regional climate change database, Scenario Generator (SCENGEN). Three alternative emission scenarios were combined with data from 14 general circulation model experiments. The assessment results of forest resources using RipFor, a forest-soil-atmosphere model, show that climate warming would enhance forest growth in Estonia resulting in increased productivity (2–9%) of harvestable timber on highly productive sites. Nutrient mobility increases greatly and in highly permeable soils with stable vegetation, increased mobility may result in nutrient losses through leaching. The assessment results of water resources using the simple water balance model, WatBal, show that the runoff regime of Estonian rivers would equilibrate and the groundwater table would rise. Climate warming would not cause any particular problems with water supply but the groundwater quality may suffer from increased leaching. Due to milder winters and increased storminess, the destruction of coastal areas, inundation of wetlands and disappearance of rare plant communities in coastal areas would be the most damaging results of climate change. Most sandy beaches high in recreational value would disappear. However, isostatic uplift and settlements inland from the present coastline reduce the risk of socio-economic decline. This revised version was published online in July 2006 with corrections to the Cover Date.     

South East Europe electricity roadmap – modelling energy transition in the electricity sectors

One of the most important challenges for the South East Europe region will be replacing more than 30% of its presently installed fossil fuel generation capacity by the end of 2030, and more than 95% by 2050 if its age structure is considered. This requires a strong policy framework to incentivise new investments in a region currently lacking investors, but also presents an opportunity to shape the electricity sector over the long term according to the broader energy transition strategy of the EU and the Energy Community. The aim of this paper is to assess what type of long-term pathways exist for electricity sector development in the region if they follow the energy transition process of the EU. In this model-based scenario assessment, long term electricity sector futures are explored using a set of interlinked electricity models evaluating the level of renewable energy investment required in the region to reach a deep decarbonization target, assuming emission reduction above 94% by 2050 compared to 1990 in line with the long term market integration and climate policy goals of the EU. It also explores what are the most important system wide impacts of the high deployment of renewable energy concerning generation adequacy and security of supply.

Key policy insights

• Energy policies in the South East Europe (SEE) region, both at the national and regional level, should focus on enabling renewable energy integration, as this will be a key component of the future energy mix.

• EU and Energy Community policies should be incorporated into national energy planning to ensure that SEE countries embark on the energy transition process at an early stage.

• Stranded costs should be carefully considered in decision-making on new fossil-fuel generation and gas network investment in order to avoid lock-in to carbon intensive technologies.

• If consistent decarbonization policy prevails, with a significant and persistent CO2 price signal, the role of natural gas remains transitory in the region.

• The SEE region offers relatively cheap decarbonization options: the power sector can reduce GHG emissions above 94% by 2050 in the modelled scenarios.

     

Extending the Shared Socioeconomic Pathways for sub-national impacts,adaptation, and vulnerability studies

The exploration of alternative socioeconomic futures is an important aspect of understanding the potential consequences of climate change. While socioeconomic scenarios are common and, at times essential, tools for the impacts, adaptation and vulnerability and integrated assessment modeling research communities, their approaches to scenario development have historically been quite distinct. However, increasing convergence of impacts, adaptation and vulnerability and integrated assessment modeling research in terms of scales of analysis suggests there may be value in the development of a common framework for socioeconomic scenarios. The Shared Socioeconomic Pathways represents an opportunity for the development of such a common framework. However, the scales at which these global storylines have been developed are largely incommensurate with the sub-national scales at which impacts, adaptation and vulnerability and, increasingly, integrated assessment modeling studies are conducted. The objective of this study was to develop sub-national and sectoral extensions of the global SSP storylines in order to identify future socioeconomic challenges for adaptation for the U.S. Southeast. A set of nested qualitative socioeconomic storyline elements, integrated storylines, and accompanying quantitative indicators were developed through an application of the Factor–Actor–Sector framework. In addition to revealing challenges and opportunities associated with the use of the SSPs as a basis for more refined scenario development, this study generated sub-national storyline elements and storylines that can subsequently be used to explore the implications of alternative sub-national socioeconomic futures for the assessment of climate change impacts and adaptation.     

Tradable permit programs: What are the lessons for the new Alaska halibut catch sharing plan?

To address long-standing allocation conflicts between the Pacific halibut commercial fishing sector and recreational charter (for-hire) sector in Alaska, an Alaska halibut catch sharing plan (CSP) is being implemented in 2014 that has a provision allowing the leasing of commercial individual fishing quota to recreational charter businesses. This one-way inter-sectoral trading allows for the charter sector to increase its share of the total allowable catch while compensating commercial fishermen. This type of catch shares program is novel in fisheries. In this paper, the literature on non-fisheries tradable permit programs (TPPs) that have similarities to the Alaska halibut CSP program is examined. Several successful TPPs are discussed, including ones from emissions trading programs, water quality trading programs, water markets, and transferable development rights programs. They are then evaluated in terms of their similarities and differences to the Alaska CSP program. Characteristics not part of the current CSP that other TPPs have used and that may increase the likelihood for the CSP to be effective in achieving its primary goals (if they are implemented) are identified, such as allowing more flexible transfers (e.g., internal transfers), intertemporal banking, cooperative structures, and multi-year leasing.