Phys.org November 4, 2024
The Atlantic meridional overturning circulation (AMOC) and the Amazon forest are viewed as connected tipping elements in a warming climate system. If global warming exceeds a critical threshold, the AMOC may slow down substantially, changing atmospheric circulation and leading to Amazonia becoming drier in the north and wetter in the south. An international team of researchers (Brazil, Morocco, Germany, Switzerland, the Netherlands, UK, France, China, USA – Keller Science Action Center) used pollen and microcharcoal data from a marine sediment core to assess changes in Amazon vegetation from 25,000 to 12,500 years ago and modeled vegetation responses to an AMOC slowdown under both glacial and pre-industrial conditions. During a past AMOC slowdown, pollen data showed a decline in cold- and moist-affinity elements, coupled with a rise in seasonal tropical vegetation. According to the researchers their modelling suggests similar changes for a comparable AMOC slowdown under pre-industrial conditions. Combined with current disturbances such as deforestation and wildfires elsewhere in the basin, an AMOC slowdown may exert a systemic impact on the Amazon forest… read more. Open Access TECHNICAL ARTICLE
Study region and representativity of the marine pollen spectra. Credit: Nature Geoscience, 1 November 2024