Detecting Patterns of Climate Change at Volcán Chimborazo, Ecuador, by Integrating Instrumental Data, Public Observations, and Glacier Change Analysis

Abstract

The people of Andean Ecuador face considerable risks due to climate change; however, a fundamental obstacle for those seeking to understand these risks is the lack of detailed, long-term meteorological data for the region. This research describes recent patterns of climate change at Volcán Chimborazo, Ecuador, through an integration of climatological data, qualitative data provided by local residents, and information derived from a detailed analysis of recent glacier change on the mountain. Although instrumental records indicate a local warming of 0.11°C decade⁻¹ between 1986 and 2011 (0.26°C total), these data suggest that precipitation has remained largely unchanged. Local residents (farmers and nonfarmers, irrigators and nonirrigators), however, report that there has been a noticeable reduction in rainfall and surface water availability in recent decades, and the near ubiquity of this observation suggests that the instrumental record has not captured these patterns of climate change. Between 1986 and 2013, Chimborazo experienced a 21 percent (±9 percent) reduction in ice surface area and a 180 m increase in the mean minimum elevation of non-debris-covered ice. Because measured warming can only account for an ∼50 m increase in freezing level height, these changes indicate that shifting precipitation patterns are indeed occurring. These results show that integrating information from a variety of empirical and nonempirical sources provides valuable information about local manifestations of climate change that might otherwise remain unrecognized in highly heterogeneous mountain landscapes. This integrative capacity is a unique—and critically important—contribution that geographers can make to climate change science.

安第斯地区的厄瓜多尔人正面临因气候变迁所导致的重大风险；但对于企图理解这些风险的研究者而言，最根本的困难在于该区域缺乏仔细且长期的气象数据。本研究透过整合气候数据、地方居民提供的质性数据，以及从晚进山区冰河变迁的细緻分析获得的数据，描绘厄瓜多尔钦博拉索山晚近的气候变迁模式。尽管工具记录显示，1986 年至 2011 年间，每十年有 0.11℃（共 0.26℃）的地方暖化，这些数据却显示降雨仍大幅维持不变。地方居民（农民与非农民、灌溉者与非灌溉者）却回报近数十年来，降雨和可使用的地表水显着减少，而此般几乎普遍存在的观察，意味着工具记录未能捕捉这些气候变迁的模式。1986 年至 2013 年间，钦博拉索的冰表层面积减少了百分之二十一（正负百分之九），而未受岩层覆盖的冰的最小海拔平均数增加了一百八十公尺。由于测得的暖化仅能说明结冰层高度约五十公尺的增加，因此这些改变意味着转变中的降雨模式的确正在发生。这些研究结果显示，整合来自多样经验与非经验性的信息，为气候变迁的地方展现提供了宝贵的信息，且若缺少这些信息的话，气候变迁在高度异质的山区地景中的展现将持续未能受到指认。此般整合能力是地理学者能够对气候变迁科学做出的特殊——且相当关键——之贡献。

La gente de la parte andina del Ecuador enfrenta riesgos serios debido al cambio climático; sin embargo, a quienes pretenden entender aquellos riesgos se les presenta un obstáculo fundamental, cual es la falta de datos meteorológicos detallados y de suficiente antigüedad sobre la región. Esta investigación describe patrones recientes del cambio climático en el Volcán Chimborazo, en Ecuador, por medio de la integración de datos climatológicos, datos cualitativos suministrados por los residentes locales y la información derivada de un análisis minucioso del cambio frecuente de los glaciares de la montaña. Aunque los registros instrumentales indican un calentamiento local de 0.11°C por década^–1 entre 1986 y 2011 (0.26°C en total), estos datos sugieren que la precipitación en gran medida ha continuado sin alteraciones. No obstante, los residentes locales (agricultores y otros, practicantes de regadío y otros) informan que en décadas recientes se ha presentado una apreciable reducción de las lluvias y en la disponibilidad de agua corriente, y el carácter casi ubicuo de esta observación sugiere que el registro instrumental no ha captado estos patrones de cambio climático. Entre 1986 y 2013, el Chimborazo experimentó un 21 por ciento (± 9 por ciento) de reducción en el área cubierta de hielo y un incremento de 180 m en la media mínima de elevación del hielo no cubierto con debris. Debido a que el calentamiento registrado apenas puede responder por un incremento de ∼50 m en la altura del nivel de congelamiento, estas transformaciones indican que en verdad se está dando un cambio en los patrones de precipitación. Estos resultados muestran que integrar la información procedente de una variedad de fuentes empíricas y no empíricas genera datos valiosos acerca de las manifestaciones locales del cambio climático, que de otra manera podrían permanecer sin reconocimiento en los altamente heterogéneos paisajes montañosos. Tal capacidad integradora es una contribución única—y críticamente importante––que los geógrafos pueden hacer a la ciencia del cambio climático.

Key Words:

• Andes Mountains
• climate change
• Ecuador
• glacier change
• mixed methods

关键词：:

• 安第斯山，气候变迁，厄瓜多尔，冰河改变，混合方法。

Palabras clave:

• Montañas de los Andes
• cambio climático
• Ecuador
• cambio glaciario
• métodos mixtos

Acknowledgments

The authors wish to acknowledge Ecuador's Instituto Nacional de Meteorología e Hidrología (INAMHI), particularly Bolivar Cáceres and Luis Maisincho, for providing data and overall support; Paul Morin of the Polar Geospatial Center at the University of Minnesota for assistance with imagery; Nellie McLean-Browne and Ximena Raza for assistance with household surveys; Frank Paul of the University of Zürich for his helpful comments on an earlier draft of this article; Zoe Pearson of the University of Wyoming for many thoughtful suggestions; and the anonymous reviewers who greatly aided in improving this work. Jeff La Frenierre is grateful to his PhD committee members, Bryan G. Mark, Kendra McSweeney, W. Berry Lyons, Ellen Mosely-Thompson, and Michael Durand, for guidance throughout this project, as well as numerous Ecuadorian and U.S. friends and colleagues for assistance and company while in the field.

Funding

Funding for this research was provided by the National Science Foundation's Doctoral Dissertation Research Improvement Grant #1103235, the Fulbright Commission of Ecuador, and the Geological Society of America.

Additional information

Notes on contributors

Jeff La Frenierre

JEFF LA FRENIERRE is an Assistant Professor in the Department of Geography and the Environmental Studies Program at Gustavus Adolphus College, St. Peter, MN 56082. E-mail: [email protected]. His research interests include glacier change analysis, the hydrological consequences of environmental change, climate change resilience and vulnerability, mountain geography, and problem solving using geospatial technologies.

Bryan G. Mark

BRYAN G. MARK is a Professor in the Department of Geography and at the Byrd Polar and Climate Research Center at The Ohio State University, Columbus, OH 43210. E-mail: [email protected]. His research interests include climate–glacier–hydrologic dynamics, coupled human–natural systems of water resources, and paleoclimatology. He is currently the State Climatologist for Ohio.