英国控制气候变化政策框架

英国政府对气候变化十分关注，已制定出防止气候变化的具体方案。本文对该方案做了简要介绍。在该方案中，到2010年，二氧化碳的排放量将比1990年减少20％。为了达到这个目标，英国对各主要行业的温室气体减排措施和减排潜力作了详细分析，使该政策框架具有可操作性。

控制气候变化的国际法律问题探析

控制气候变化的国际合作是极其艰巨复杂的,必须建立科学有效的国际法律制度。但现行制度很大程度上是大国利益妥协的产物,存在很多缺陷,制约着现行机制发挥最大效用。希望2009年召开的哥本哈根气候变化会议对现行机制能做出相应的改善,使控制气候变化的国际合作更加有力有效。

On assessing haze attribution and control measures in China

This paper analyzes the air pollution situation in China,particularly the severe intensifying tendency in central North China.Five major comments on the air pollution issue in China are proposed,emphasizing the scientific understanding on the mechanisms of air pollution formation processes,the interannual variability,the relative roles of climate change and pollutant emissions,the interaction between climate change and atmospheric chemical processes,and the seasonal prediction of air pollution.The viewpoints have significance for air pollution management in China and around the world.

Spatial Scale Effects of Water Erosion Dynamics:Complexities, Variabilities, and Uncertainties

Severe water erosion is notorious for its harmful effects on land-water resources as well as local societies. The scale effects of water erosion, however, greatly exacerbate the difficulties of accurate erosion evaluation and hazard control in the real world. Analyzing the related scale issues is thus urgent for a better understanding of erosion variations as well as reducing such erosion. In this review article, water erosion dynamics across three spatial scales including plot, watershed, and regional scales were selected and discussed. For the study purposes and objectives, the advantages and disadvantages of these scales all demonstrate clear spatial-scale dependence. Plot scale studies are primarily focused on abundant data collection and mechanism discrimination of erosion generation, while watershed scale studies provide valuable information for watershed management and hazard control as well as the development of quantitatively distributed models. Regional studies concentrate more on large-scale erosion assessment, and serve policymakers and stakeholders in achieving the basis for regulatory policy for comprehensive land uses. The results of this study show that the driving forces and mechanisms of water erosion variations among the scales are quite different. As a result, several major aspects contributing to variations in water erosion across the scales are stressed: differences in the methodologies across various scales, different sink-source roles on water erosion processes, and diverse climatic zones and morphological regions. This variability becomes more complex in the context of accelerated global change. The changing climatic factors and earth surface features are considered the fourth key reason responsible for the increased variability of water erosion across spatial scales.

Carbon Dioxide Control-Technology for the Future

The world is experiencing global climate change, and most scientists attribute it to the accumulation in the atmosphere of carbon dioxide, methane, nitrous oxide, and chlorofluorocarbons. Because of its enormous emission rate, carbon dioxide （CO2） is the main culprit. Almost all the anthropogenic CO2 emissions come from the burning of fossil fuels for electricity, heat, and transportation. Emissions of COg can be reduced by conservation, increased use of renewable energy sources, and increased efficiencies in both the production of electrical power and the transportation sector. Capture of CO2 can be accomplished with wet scrubbing, dry sorption, or biogenic fixation. After CO2 is captured, it must be transported either as a liquid or a supercritical fluid, which realistically can only be accomplished by pipeline or ship. Final disposal of CO2 will either be to underground reservoirs or to the ocean; at present, the underground option seems to be the only viable one. Various strategies and technologies involved with reduction of CO2 emissions and carbon capture and sequestration （CCS） are briefly reviewed in this paper.

Germination strategies under climate change scenarios along an aridity gradient

Aims Climate change in the eastern Mediterranean region will have a strong impact on ecosystem functioning and plant community dynamics due to a reduction in annual rainfall and increased variability.We aim to understand the role of seed banks as potential buffers against climatic uncertainty determined by climate change.Methods We examined germination strategies of 18 common species present along an aridity gradient.Data were obtained from soil seed banks germinated during nine consecutive years from arid,semi-arid,Mediterranean and mesic Mediterranean ecosystems.At the semi-arid and Mediterranean sites,rainfall manipulations simulating 30%drought and 30%rainfall increase were applied.Germination strategies were tested under optimal irrigation conditions during three consecutive germination seasons to determine overall seed germinability in each soil sample.Changes in germination strategy were examined using a novel statistical approach that considers the climatic and biotic factors that may affect seed germinability.Important Findings The results showed that dominant species controlled their germination fractions by producing seeds with a different yearly germination fraction probability.The amount of rainfall under which the seeds were produced led to two major seed types with respect to germinability:high germinability,seeds leading to transient seed banks,and low germinability,seeds leading to persistent seed banks.We conclude that differential seed production among wet and dry years of both seed types creates a stable balance along the aridity gradient,enabling the soil seed bank to serve as a stabilizing mechanism buffering against rainfall unpredictability.Additionally,we present a general model of germination strategies of dominant annual species in Mediterranean and arid ecosystems that strengthens the notion of soil seed banks as buffers against climatic uncertainty induced by climate change in the region.