When Alexander von Humboldt set out to explore the American continent, he came across terrestrial and marine (eco-)systems that are considered tipping elements today. Small perturbations linked to climate change may trigger abrupt and/or irreversible change in these systems. If Alexander von Humboldt had undertaken his expedition in modern times, he might have studied potential tipping behavior of the marine biological carbon pump, the Amazon rainforest, coral reefs in the Caribbean Sea, and the El Niño-Southern Oscillation (one of the major oceanic/atmospheric circulation modes on Earth). Likewise, when he later travelled across the vast plains of Russia, he might have been most interested in signs of approaching tipping points in boreal forests, permafrost soils, Tibetan glaciers, and marine methane hydrates off the Siberian coast. Here, we follow Alexander von Humboldt on a mental journey. We present recent scientific findings on tipping elements that are located along his expedition routes. To conclude, we sketch a research agenda whose successful completion would provide society with the knowledge and tools required to handle the risks arising from tipping elements.
Huber V. & Schellnhuber M. L., 2010. A tipping-elements expedition in the footsteps of Alexander von Humboldt. Nova Acta Leopoldina NF 112:29-42. Article.
