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Chapter 3 - Changes in Climate Extremes and their Impacts on the Natural Physical Environment
- from Section III
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- By Sonia I. Seneviratne, Neville Nicholls, David Easterling, Clare M. Goodess, Shinjiro Kanae, James Kossin, Yali Luo, Jose Marengo, Kathleen McInnes, Mohammad Rahimi, Markus Reichstein, Asgeir Sorteberg, Carolina Vera, Xuebin Zhang, Matilde Rusticucci, Vladimir Semenov, Lisa V. Alexander, Simon Allen, Gerardo Benito, Tereza Cavazos, John Clague, Declan Conway, Paul M. Della-Marta, Markus Gerber, Sunling Gong, B. N. Goswami, Mark Hemer, Christian Huggel, Bart van den Hurk, Viatcheslav V. Kharin, Akio Kitoh, Albert M.G. Klein Tank, Guilong Li, Simon Mason, William McGuire, Geert Jan van Oldenborgh, Boris Orlowsky, Sharon Smith, Wassila Thiaw, Adonis Velegrakis, Pascal Yiou, Tingjun Zhang, Tianjun Zhou, Francis W. Zwiers
- Edited by Christopher B. Field, Vicente Barros, Thomas F. Stocker, Qin Dahe
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- Book:
- Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation
- Published online:
- 05 August 2012
- Print publication:
- 28 May 2012, pp 109-230
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Summary
Executive Summary
This chapter addresses changes in weather and climate events relevant to extreme impacts and disasters. An extreme (weather or climate) event is generally defined as the occurrence of a value of a weather or climate variable above (or below) a threshold value near the upper (or lower) ends (‘tails’) of the range of observed values of the variable. Some climate extremes (e.g., droughts, floods) may be the result of an accumulation of weather or climate events that are, individually, not extreme themselves (though their accumulation is extreme). As well, weather or climate events, even if not extreme in a statistical sense, can still lead to extreme conditions or impacts, either by crossing a critical threshold in a social, ecological, or physical system, or by occurring simultaneously with other events. A weather system such as a tropical cyclone can have an extreme impact, depending on where and when it approaches landfall, even if the specific cyclone is not extreme relative to other tropical cyclones. Conversely, not all extremes necessarily lead to serious impacts. [3.1]
Many weather and climate extremes are the result of natural climate variability (including phenomena such as El Niño), and natural decadal or multi-decadal variations in the climate provide the backdrop for anthropogenic climate changes. Even if there were no anthropogenic changes in climate, a wide variety of natural weather and climate extremes would still occur. [3.1]
A changing climate leads to changes in the frequency, intensity, spatial extent, duration, and timing of weather and climate extremes, and can result in unprecedented extremes. Changes in extremes can also be directly related to changes in mean climate, because mean future conditions in some variables are projected to lie within the tails of present-day conditions. Nevertheless, changes in extremes of a climate or weather variable are not always related in a simple way to changes in the mean of the same variable, and in some cases can be of opposite sign to a change in the mean of the variable. Changes in phenomena such as the El Nino-Southern Oscillation or monsoons could affect the frequency and intensity of extremes in several regions simultaneously. [3.1]
2 - Observed changes in the global distribution of daily temperature and precipitation extremes
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- By David R. Easterling, National Climatic Data Center NOAA, 151, Patton Ave Asheville, NC 28801, USA
- Edited by Henry F. Diaz, National Oceanic and Atmospheric Administration, District of Columbia, Richard J. Murnane
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- Book:
- Climate Extremes and Society
- Published online:
- 14 September 2009
- Print publication:
- 22 May 2008, pp 24-34
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Summary
Condensed summary
Observed changes in climate extremes have been documented for both temperature and precipitation in many parts of the globe. These changes include decreases in frost days and a lengthening of the frost-free season, increases in the number of days with temperatures above percentile-based thresholds, and increases in heavy precipitation events. These changes are generally consistent with observed warming in mean annual temperatures, and with observed changes in annual precipitation.
Introduction
This chapter reviews the scientific literature on variability and change in observed climate extremes over the globe. Observed changes in extremes should be considered in light of observed changes in mean quantities, including observed changes in annual average temperature, and changes in maximum and minimum temperatures and the diurnal temperature range (DTR) (Easterling et al., 1997; Vose et al., 2005). The globally averaged annual temperature (Fig. 2.1) shows a linear increase of approximately 0.6 degrees per century since the late 1800s, but the rate of increase since the mid 1970s has itself increased to approximately 2 degrees per century. Seasonally, the strongest increases have occurred in the boreal winter (December–January–February, DJF) and spring (March–April–May, MAM). Figure 2.2 shows that, regionally, the southeastern United States and northern Atlantic continue to show a trend to cooling, but the southeastern US trend appears to be getting smaller with each additional year of data; the largest increases in temperature have occurred in the high latitudes of the Northern Hemisphere.
2 - The research strategy: linking the local to the global
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- By Thomas J. Wilbanks, Corporate Research Fellow and Leader of Global Change and Developing country Programs Oak Ridge National Laboratory (ORNL)., Robert W. Kates, University Professor Brown University, David P. Angel, Associate Professor of Geography and Dean of Graduate Studies and Research Clark University, Susan L. Cutter, Carolina Distinhuished Professor University of South Carolina, William E. Easterling, Professor of Geography and Earth System Science Pennsylvania State University, Michael W. Mayfield, Professor Department of Geography and Planning, Appalachian State University
- Association of American Geographers GCLP Research Team
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- Book:
- Global Change and Local Places
- Published online:
- 31 July 2009
- Print publication:
- 26 June 2003, pp 27-54
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Summary
In the beginning …
The Global Change and Local Places project of the Association of American Geographers originated in a 1992 meeting at which participants formulated three propositions:
The grand query regarding the ways scale matters in understanding global climate change would benefit from detailed case studies of localities that were linked to scholars active in climate change-related research at global and national scales;
Such case studies could constitute a basis for designing a research protocol for use in other local case studies, thereby helping build a body of empirical research that could serve as a basis for developing a bottom-up paradigm for global climate change research to complement the dominant top-down paradigm; and
These locality studies should be based at universities whose faculty possessed detailed, long-term knowledge of their local areas, in some cases engaging scholars in global change research who might otherwise not normally participate in a large-scale research project.
Funding for the project outlined at the 1992 meeting was sought and eventually obtained from the National Aeronautics and Space Administration's Mission to Planet Earth Program (subsequently renamed Destination Earth). Intensive work on the project began in 1996 and continued through 2001. The several rounds of proposal writing that preceded funding refined the theoretical rationale for the project and its central components: four study areas located in Kansas, North Carolina, Ohio, and Pennsylvania; and three cross-cutting modules devoted respectively to estimating local greenhouse gas emissions, understanding the forces driving those emissions, and assessing local emission reduction potentials.