University of East Anglia

About: University of East Anglia is a education organization based out in Norwich, Norfolk, United Kingdom. It is known for research contribution in the topics: Population & Climate change. The organization has 13250 authors who have published 37504 publications receiving 1669060 citations. The organization is also known as: UEA.

Time Series Modelling and Interpretation

Abstract: SUMMARY By considering the model generating the sum of two or more series, it is shown that the mixed ARMA model is the one most likely to occur. As most economic series are both aggregates and are measured with error it follows that such mixed models will often be found in practice. If such a model is found, the possibility of resolving the series into simple components is considered both theoretically and for simulated data. 1. INrRODUCTION THE recent publication of the book by Box and Jenkins has greatly increased interest by time series analysts and econometricians in more complicated, even if more "parsimonious", time series models. However, the intuitive interpretation of the models that arise is not always simple and an applied research worker may well ask how such a model could have arisen in practice. In this paper, the possibility that a complicated looking model could have arisen from a simpler situation is explored and some suggestions made about the possible interpreta- tion of some models that appear to arise in practice. The only series to be considered are those with zero means and generated by models with time-invariant parameters. Thus, possibly after an appropriate linear transformation, the series will be taken to be second-order stationary. Let Xi be such a series, so that E{X} =O, all t.

Problems with making and governing global kinds of knowledge.

Abstract: During its 20 years of publication, the journal Global Environmental Change has given visibility and coherence to the eponymous research paradigm. Global environmental research has brought forth new kinds of knowledge about the multi-scale interactions between physical and social dimensions of the environment. This essay reflects on some of the problems with making and governing these global kinds of knowledge, as suggested through the perspectives of a nascent geography of science. I use climate change – an emblematic theme of global environmental change research over the last 20 years – to examine three facets of the global environmental change paradigm: making global kinds of knowledge, globalising environmental values and the governance of knowledge-making. New global kinds of knowledge have gained power and visibility in contemporary scientific, public and political fora and yet such knowledge can be ‘brittle’, easily cracked and broken. A geography of global environmental change knowledge therefore demands we turn our attention away from the globalising instincts that so easily erase difference and collapse meaning, and instead concern ourselves with understanding the relationships between knowledge-making and human culture in evolving places. Only then will we recognise the ambiguities, voids and blind spots in our understanding of the world's complexity.

Climate and southern Africa's water-energy-food nexus

Abstract: In southern Africa, the connections between climate and the water–energy–food nexus are strong. Physical and socioeconomic exposure to climate is high in many areas and in crucial economic sectors. Spatial interdependence is also high, driven, for example, by the regional extent of many climate anomalies and river basins and aquifers that span national boundaries. There is now strong evidence of the effects of individual climate anomalies, but associations between national rainfall and gross domestic product and crop production remain relatively weak. The majority of climate models project decreases in annual precipitation for southern Africa, typically by as much as 20% by the 2080s. Impact models suggest these changes would propagate into reduced water availability and crop yields. Recognition of spatial and sectoral interdependencies should inform policies, institutions and investments for enhancing water, energy and food security. Three key political and economic instruments could be strengthened for this purpose: the Southern African Development Community, the Southern African Power Pool and trade of agricultural products amounting to significant transfers of embedded water.