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Abstract: Climate change is increasingly been called a ‘security’ problem, and there has been speculation that climate change may increase the risk of violent conflict. This paper integrates three disparate but well-founded bodies of research – on the vulnerability of local places and social groups to climate change, on livelihoods and violent conflict, and the role of the state in development and peacemaking, to offer new insights into the relationships between climate change, human security, and violent conflict. It explains that climate change increasingly undermines human security in the present day, and will increasingly do so in the future, by reducing access to, and the quality of, natural resources that are important to sustain livelihoods. Climate change is also likely to undermine the capacity of states to provide the opportunities and services that help people to sustain their livelihoods. We argue that in certain circumstances these direct and indirect impacts of climate change on human security may in turn increase the risk of violent conflict. The paper then outlines the broad contours of a research programme to guide empirical investigations into the risks climate change poses to human security and peace. [Copyright &y& Elsevier]

Abstract: The papers in this special issue are derived from a selection of presentations given at the RACHAD workshop titled “Pattern of Holocene Climate Change in Central Asia: Data Synthesis” held at Lanzhou University, People''s Republic of China, from 25th to 27th July 2006. RACHAD is INQUA Palaeoclimate Commission (PALCOMM) Project (#0502), concerned with ‘rapid climate change in Central Asia''s drylands’, and the 2006 workshop was its fourth gathering. The RACHAD project was established in 2000 and has been led by Prof Fahu Chen from Lanzhou University. RACHAD''s initial objectives were to stimulate the reconstruction of Holocene climatic and environmental changes in arid Central Asia at high resolution, to intensify international research collaboration, and to develop and refine techniques for environmental reconstruction and dating. [Copyright &y& Elsevier]

Abstract: The debate on the enhanced greenhouse effect continues, confusing the climate change impact analysis and the decision makers. Hence, this paper is addressed to the extreme regional-scale evaluation of global climate model (GCM). Given that assessment of models is crucial to consider future scenarios in climate change impact analyses, the exploratory work is essential, as it identifies the strengths and weaknesses of GCM to regional-scale differences in model performance, providing insights on regional-scale climate interactions and processes. That is why this manuscript attempts to compare the spatial pattern of a longer temporal aggregation period (1960/61–1989/90) for extreme temperatures simulated by a particular GCM (HadCM3) to that of NCEP Reanalyses, which are considered as “truth”. Climatic risk analyses and forecasting, concern among other topics, assess an interpretation in intensity and frequency of recurrence of long duration extreme values (heat/cold waves). One study assesses the impact of extreme events analysing the temporal dependence of extreme events. The present study leads to the conclusion that the HadCM3 Simulations do not reproduce reasonably the NCEP Reanalyses over the Modelling the Impact of Climate Extremes (MICE—EU Project) domain, even despite the fact that the climatology of extremes has demonstrated very similar spatial patterns. Consequently, all diagnostics of extremes led support to the fitted Generalised Extreme Value (GEV) model for extrapolation, suggesting that the HadCM3 is not adequate for forecasting, simulating future scenarios of extremes based on the analysis of risk or probability maps for spatial uncertainties. The greatest difference between the two models is in terms of the precision of estimation. [Copyright &y& Elsevier]

It is well known that there is a vast expanse of grassland on the Tibetan Plateau, China. It is suggested that a major climatic factor limiting production of the grassland ecosystem is the low thermo-conditions on the Tibetan Plateau. An increase in temperature may therefore increase the productivity of grasslands on the Plateau. Monthly mean temperature and monthly precipitation data for recent years on the Tibetan Plateau were analyzed. It is clear that the increase in air temperature on the Plateau is greater than that in the whole China and East Asia. On the other hand, statistics show that the production of livestock or meat in the Tibetan Plateau has increased by one to three times since 1978, which means that there should be an equivalent increase in the consumption of plant biomass from the grassland. How is the “increased biomass” related to human activities and climate changes? This paper tries to clarify the relationship between human activities and climate change and to propose a possible answer by laying emphasis on the importance of grassland protection and CO2 flux monitoring. It is suggested that there is a positive feedback in which degradation of grassland by overgrazing will increase potential evapotranspiration level thereby promoting the climate warming and the degradation process. This feedback should be considered seriously in the future. [Copyright &y& Elsevier]

Climate in northeast Qinghai–Tibetan Plateau is characterised by the alternation of summer and winter monsoon circulation, which is generated by thermodynamic and kinetic effects of the immense plateau. The Plateau Monsoon system during the recent geological past has been investigated through a 44-m loess–paleosol section and a 17-m well to obtain the Plateau Monsoon climate changes during the last glacial–interglacial cycle.Thermoluminescence (TL) and optically stimulated luminescence (OSL) methods, as well as field observations and stratigraphic correlation, are used to date the deposit. Magnetic susceptibility (MS), frequency-dependent magnetic susceptibility (FMS), and calcium carbonate content, which are regarded as proxy indicators of strength of the Plateau Summer Monsoon (PSM), are measured. Measurement of grain size distribution, which is regarded as a proxy index of strength of the Plateau Winter Monsoon (PWM), is also carried out. The results show that changes of the unique Plateau Monsoon system during the past 130 kyr are associated with the glacial and interglacial alternations in the Northern Hemisphere. The PSM was unusually strengthened during a period matching the marine oxygen isotope stage 5e (OIS 5e), but it was weak during the OIS 5a and OIS 5c, and was close to that of the OIS 3. The PWM was significantly depressed during OIS 3, and was as weak as that in the Holocene. The PWM and PSM circulations were not always coupled during the last glacial cycle. Changes of the Plateau Monsoon system did not always parallel the SE Asian monsoon, although linkage between them existed to some extent.There are millennial-scale variations in the Plateau Monsoon system, but this is not further discussed in this paper. [Copyright &y& Elsevier]