The beginning of the Anthropocene, a proposed geological epoch denoting human-caused changes to Earth’s systems, and what metrics signify its onset is currently under debate. Proposed initiation points range from the beginning of the Atomic Age to the Industrial Revolution to the adoption of agriculture in the early Holocene. Most of the debate centers on the effects of modern industrially oriented technological and economic development. The effects of preindustrial and preagricultural populations on Earth’s systems are less commonly evaluated. Because the utility of the Anthropocene concept is to denote measurable impacts of human activity on Earth’s systems, we argue that focusing on an exact date or single event ignores time-transgressive, spatially variable processes of anthropogenic ecosystem engineering. We argue instead for a flexible, anthropologically and ecologically informed conceptualization of the Anthropocene—one that recognizes spatial, temporal, and scalar variability in the effects of humans on Earth systems. We present evidence in support of an ecologically informed pre-Columbian Anthropocene in California using a meta-analysis of sedimentological, palynological, and archaeological data sets from California mountains. We argue that use of fire for resource management by pre-Columbian populations was sufficiently frequent and extensive enough to result in widescale anthropogenic modification of California’s biota and that an Anthropocene therefore began in California by at least 650 years ago, centuries before the arrival of Europeans. Recognizing a pre-Columbian Anthropocene in California constructively conceptualizes a marker for human economic–ecological intensification processes that could be more meaningful for policy, resource management, and research than focusing on any single historical event.

人类世的开始，一个提议的地质时期，它表示人为导致的地球系统的变化，以及衡量其发生的度量标准目前正在辩论中。提议的起始点范围从原子时代的开始到工业革命再到全新世早期的农业采用。大多数辩论集中在以现代工业为导向的技术和经济发展的影响上。工业界和农业前人口对地球系统的影响很少被评估。由于人类世概念的效用是表示人类活动对地球系统的可测量影响，因此我们认为，关注确切的日期或单个事件会忽略人类活动的生态系统工程的时间跨度，空间可变过程。我们主张灵活，从人类学和生态学角度出发的人类世系概念化，它认识到人类对地球系统的影响在空间，时间和标量上的变化。我们使用来自加利福尼亚山区的沉积学，孢粉学和考古数据集的荟萃分析，提供了支持加利福尼亚州生态知情的哥伦比亚前人类世的证据。我们认为，前哥伦布时期的居民使用火进行资源管理足够频繁和广泛，足以对加利福尼亚生物群进行大规模的人为改造，因此人类世始于加利福尼亚，至少在650年前，即欧洲人到来之前的几个世纪。