Author: Xiuquan Wang Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
Human-induced climate change has been regarded as one of the most pressing issues around the world because it often leads to severe, widespread, and irreversible consequences. Assessing the potential impacts of climate change is essential and critical for developing appropriate mitigation and adaptation strategies against the changing climate. In this research, a series of approaches and methodologies have been proposed for dealing with the challenges in climate change impact assessment due to the lack of highresolution climate projections and the difficulty in quantifying the uncertainties associated with future climate projections. The proposed approaches and methodologies have been applied to the Province of Ontario, Canada to demonstrate their effectiveness in generating probabilistic and high-resolution regional climate scenarios. Specifically, a new statistical downscaling tool, named SCADS, has been developed to help perform rapid development of downscaled scenarios under current and future climate forcing conditions. The SCADS uses a cluster tree to effectively deal with continuous and discrete variables, as well as nonlinear relations between large-scale atmospheric variables and local surface ones. A hybrid downscaling approach by coupling the PRECIS model and the SCADS model has been proposed to construct high resolution climate projections for studying climate change impacts at local scales. The coupled approach was applied for projecting the future climate over Ontario at a fine resolution of 10 km. A Bayesian hierarchical model has been developed to quantify the uncertainties of regional climate projections in a statistical framework based upon a limited number of explicit assumptions for prior distributions. By feeding the observations for current climate and the PRECIS ensemble simulations into the Bayesian model, probabilistic projections of future climatic changes over Ontario have been developed. The likely changes in temperature and precipitation as well as extreme precipitation events across the Province of Ontario were evaluated to help understand its local climate's response to global warming. A public climate change data portal, named Ontario CCDP, have been established to ensure impact researchers and decision makers have free access to the high-resolution climate projections, thus supporting further impact studies and development of climate mitigation and adaptation strategies.
Author: Rao Kotamarthi Publisher: Cambridge University Press ISBN: 1108587062 Category : Science Languages : en Pages : 213
Book Description
Downscaling is a widely used technique for translating information from large-scale climate models to the spatial and temporal scales needed to assess local and regional climate impacts, vulnerability, risk and resilience. This book is a comprehensive guide to the downscaling techniques used for climate data. A general introduction of the science of climate modeling is followed by a discussion of techniques, models and methodologies used for producing downscaled projections, and the advantages, disadvantages and uncertainties of each. The book provides detailed information on dynamic and statistical downscaling techniques in non-technical language, as well as recommendations for selecting suitable downscaled datasets for different applications. The use of downscaled climate data in national and international assessments is also discussed using global examples. This is a practical guide for graduate students and researchers working on climate impacts and adaptation, as well as for policy makers and practitioners interested in climate risk and resilience.
Author: Katharine A. Hayhoe Publisher: ISBN: Category : Languages : en Pages :
Book Description
Regional climate impact assessments require high-resolution projections to resolve local factors that modify the impact of global-scale forcing. To generate these projections, global climate model simulations are commonly downscaled using a variety of statistical and dynamical techniques. Despite the essential role of downscaling in regional assessments, there is no standard approach to evaluating various downscaling methods. Hence, impact communities often have little awareness of limitations and uncertainties associated with downscaled projections. To develop a standardized framework for evaluating and comparing downscaling approaches, I first identify three primary characteristics of a distribution directly relevant to impact analyses that can be used to evaluate a simulated variable such as temperature or precipitation at a given location: (1) annual, seasonal, and monthly mean values; (2) thresholds, extreme values, and accumulated quantities such as 24h precipitation or degree-days; and (3) persistence, reflecting multi-day events such as heat waves, cold spells, and wet periods. Based on a survey of the literature and solicitation of expert opinion, I select a set of ten statistical tests to evaluate these characteristics, including measures of error, skill, and correlation. I apply this framework to evaluate the skill of four downscaling methods, from a simple delta approach to a complex asynchronous quantile regression, in simulating daily temperature at twenty stations across North America. Identical global model fields force each downscaling method, and the historical observational record at each location is randomly divided by year into two equal parts, such that each statistical method is trained on one set of historical observations, and evaluated on an entirely independent set of observations. Biases relative to observations are calculated for the historical evaluation period, and differences between projections for the future. Application of the framework to this broad range of downscaling methods and locations is successful in that: (1) the downscaling method used is identified as a more important determinant of data quality than station location or GCM; and (2) key differences between downscaling methods are made apparent. For tests focusing on the general distribution of the variable, all methods except bias correction are relatively successful in simulating observed climate, suggesting that if an impact is most sensitive to changes in the mean, even a relatively simple downscaling approach such as 0́−delta0́+ will significantly improve simulation of local-scale climate. For tests that focus on the tails of the distribution, however, differences do arise between simple vs. quantile-based downscaling methods. Specifically, the latter appears less sensitive to location and more consistently able to reproduce observed climate. In terms of future projections, the most notable differences between downscaling methods becomes apparent at the right-hand tail of the distribution, where simple methods tend to simulate much greater increases (up to double the extreme heat days, for some locations) than more complex downscaling methods. I conclude by discussing how a standardized evaluation framework may advance our understanding of regional climate impact studies in understanding biases and limitations in results, as well as providing critical input into the selection of downscaling methods for future assessments. Given the potential exhibited by this initial test, I explore how this evaluation framework could be expanded in the future to make it even more useful: to the regional scale, for example, by including tests for spatial correlations and forcing relationships; or across variables, to capture interactions directly relevant to impact studies, such as heat waves (a function of temperature and humidity, affecting human health, energy demand, and agriculture) or snow amounts (a function of precipitation and temperature, affecting infrastructure and ecosystems); or to evaluate a broader selection of climate variables, downscaling methods, and predictor fields.
Author: Rasmus E. Benestad Publisher: World Scientific ISBN: 9812819126 Category : Science Languages : en Pages : 228
Book Description
Empirical-statistical downscaling (ESD) is a method for estimating how local climatic variables are affected by large-scale climatic conditions. ESD has been applied to local climate/weather studies for years, but there are few ? if any ? textbooks on the subject. It is also anticipated that ESD will become more important and commonplace in the future, as anthropogenic global warming proceeds. Thus, a textbook on ESD will be important for next-generation climate scientists.
Author: Xiong Zhou Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
Climate change has been one of the most prominent and critical environmental concerns due to its potential impacts. Climate change projections, as generated through global climate models (GCMs), have been widely employed for assessments of such impacts. However, GCMs have difficulty in representing the detailed local features over limited regions. Therefore, advanced metrologies are consequently required to investigate the potential impacts of climate change. In this dissertation research, a set of integrated regional climate modeling methodologies were developed to advance the previous methodologies for potential impact assessments at regional scales under climatic changing conditions, including (a) a coupled dynamical-copula downscaling (CDCD) approach, (b) an ANOVA-based factorial dynamical downscaling (AFDD) approach, (c) a Bayesian factorial modeling (BFM) approach, (d) an ensemble RCMs-driven VIC model, (e) a stepwise cluster Bayesian (SCB) ensemble method, and (f) a mixed-level factorial inference (MLFI) approach. The developed approaches in this research could be applicable to develop future projections of climate and hydrology. Such approaches are capable of exploring the possible effects of climate change at local and regional scales. Moreover, the main and interactive effects of multiple uncertain factors on climatic and hydrologic variables could be examined based on the proposed factorial analysis approaches. The results can provide decision makers with valuable information for mitigation and adaptation of the severe impacts of climatic changes on economic, social, and environmental sectors.
Author: The BACC II Author Team Publisher: Springer ISBN: 3319160060 Category : Science Languages : en Pages : 515
Book Description
This book is an update of the first BACC assessment, published in 2008. It offers new and updated scientific findings in regional climate research for the Baltic Sea basin. These include climate changes since the last glaciation (approx. 12,000 years ago), changes in the recent past (the last 200 years), climate projections up until 2100 using state-of-the-art regional climate models and an assessment of climate-change impacts on terrestrial, freshwater and marine ecosystems. There are dedicated new chapters on sea-level rise, coastal erosion and impacts on urban areas. A new set of chapters deals with possible causes of regional climate change along with the global effects of increased greenhouse gas concentrations, namely atmospheric aerosols and land-cover change. The evidence collected and presented in this book shows that the regional climate has already started to change and this is expected to continue. Projections of potential future climates show that the region will probably become considerably warmer and wetter in some parts, but dryer in others. Terrestrial and aquatic ecosystems have already shown adjustments to increased temperatures and are expected to undergo further changes in the near future. The BACC II Author Team consists of 141 scientists from 12 countries, covering various disciplines related to climate research and related impacts. BACC II is a project of the Baltic Earth research network and contributes to the World Climate Research Programme.
Author: Patrick A. Ray Publisher: World Bank Publications ISBN: 1464804788 Category : Business & Economics Languages : en Pages : 149
Book Description
Confronting Climate Uncertainty in Water Resources Planning and Project Design describes an approach to facing two fundamental and unavoidable issues brought about by climate change uncertainty in water resources planning and project design. The first is a risk assessment problem. The second relates to risk management. This book provides background on the risks relevant in water systems planning, the different approaches to scenario definition in water system planning, and an introduction to the decision-scaling methodology upon which the decision tree is based. The decision tree is described as a scientifically defensible, repeatable, direct and clear method for demonstrating the robustness of a project to climate change. While applicable to all water resources projects, it allocates effort to projects in a way that is consistent with their potential sensitivity to climate risk. The process was designed to be hierarchical, with different stages or phases of analysis triggered based on the findings of the previous phase. An application example is provided followed by a descriptions of some of the tools available for decision making under uncertainty and methods available for climate risk management. The tool was designed for the World Bank but can be applicable in other scenarios where similar challenges arise.
Author: Cynthia Rosenzweig Publisher: Cambridge University Press ISBN: 1139497405 Category : Science Languages : en Pages : 311
Book Description
Urban areas are home to over half the world's people and are at the forefront of the climate change issue. The need for a global research effort to establish the current understanding of climate change adaptation and mitigation at the city level is urgent. To meet this goal a coalition of international researchers - the Urban Climate Change Research Network (UCCRN) - was formed at the time of the C40 Large Cities Climate Summit in New York in 2007. This book is the First UCCRN Assessment Report on Climate Change and Cities. The authors are all international experts from a diverse range of cities with varying socio-economic conditions, from both the developing and developed world. It is invaluable for mayors, city officials and policymakers; urban sustainability officers and urban planners; and researchers, professors and advanced students.
Author: Intergovernmental Panel on Climate Change. Working Group II. Publisher: Cambridge University Press ISBN: 9780521634557 Category : Science Languages : en Pages : 532
Book Description
Cambridge, UK : Cambridge University Press, 1998.
Author: Xiuquan Wang
Author: Rao Kotamarthi
Author: Katharine A. Hayhoe
Author: Rasmus E. Benestad
Author: Xiong Zhou
Author: Xander Wang
Author: The BACC II Author Team
Author: Patrick A. Ray
Author: Cynthia Rosenzweig
Author: Intergovernmental Panel on Climate Change. Working Group II.