Nonlinear climate change and Andean feedbacks: an imminent turning point?
Nonlinear climate change and Andean feedbacks: an imminent turning point?
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DOI：
10.1111/j.1365-2486.2010.02203.x
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发表时间：
2010-12
影响因子：
11.6
通讯作者：
M. Bush;Jennifer A. Hanselman;W. Gosling
中科院分区：
文献类型：
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作者：
M. Bush;Jennifer A. Hanselman;W. Gosling
来自的的喀喀湖的37万年古生态记录提供了过去气候变化的详细记录，其中间冰期被认为具有一些共同点，但也有一些关键的差异。我们提出了一个概念性的反馈模型来解释所观察到的变化，包括以前忽略的湖泊效应。今天的喀喀湖使当地环境升温约4-5 °C，并增加降雨量。我们观察到，由于温暖，干燥，间冰期的条件下，在湖水位下降，有一个可能的区域冷却的湖泊对当地小气候的影响减少。正反馈机制促进干旱，直到大部分湖盆变成盐沼。因此，通常的概念，上坡迁移的物种与变暖将不适用于高原。如果像预测的那样，下一个世纪会带来比今天更温暖和更干燥的环境，那么在大约2000年内似乎存在一个临界点。1-2在那里，北方高原相对温和的农业条件将被不适宜居住的干旱气候所取代。这种变化将对玻利维亚首都拉巴斯的公民产生深远的影响。
A 370 000‐year paleoecological record from Lake Titicaca provides a detailed record of past climate change in which interglacial periods are seen to have some elements of commonality, but also some key differences. We advance a conceptual feedback model to account for the observed changes that includes previously ignored lake effects. Today Lake Titicaca serves to warm the local environment by about 4–5 °C and also to increase rainfall. We observe that as water levels in the lake are drawn down due to warm, dry, interglacial conditions, there is a possible regional cooling as the lake effect on local microclimates diminishes. Positive feedback mechanisms promote drying until much of the lake basin is reduced to salt marsh. Consequently, the usual concept of upslope migration of species with warming would not be applicable in the Altiplano. If, as projected, the next century brings warmer and drier conditions than those of today, a tipping point appears to exist within ca. 1–2 °C of current temperatures, where the relatively benign agricultural conditions of the northern Altiplano would be replaced by inhospitable arid climates. Such a change would have profound implications for the citizens of the Bolivian capital, La Paz.