Fast & comprehensive: First version of Potsdam Earth Model POEM ready for use

In a new study published in Geoscientific Model Development, PIK scientists from the research department ‘Earth System Analysis’ coupled the state-of-the-art Dynamic Global Vegetation Model LPJmL5 to the coupled climate model developed by GFDL (CM2Mc-LPJmL v.1.0). Several improvements to LPJmL5 were implemented to allow a fully functional biophysical coupling. The new Earth model is able to capture important biospheric processes, including fire, mortality, permafrost, hydrological cycling and the impacts of managed land (crop growth and irrigation).

Using a flexible coupling software, the POEM team also successfully coupled the ice-sheet model PISM to the ocean model MOM, creating a useful tool to analyze interactions between the Antarctic Ice Sheet and the global ocean over centuries to millennia. Both coupling achievements contribute to further advance POEM, and analyze multidimensional changes of the Earth system in the Anthropocene, including interacting planetary boundaries.

First application of POEM framework: possible tipping point of Amazon

CM2Mc-LPJmL is now completed and published, which opens new opportunities to investigate important biophysical vegetation-climate feedbacks. In a first application, the team was able to find a potentially dangerous path bifurcation for tropical forests under severe climate change. Tropical rainforests could undergo detrimental transitions as a result of changing fire and biophysical feedbacks with climate. When looking at the climate-induced hysteresis, the question arises on the impact of continued tropical deforestation on increasing fire danger which might additionally destabilize tropical rainforests and possible adaptation effects, such as enhanced water-use efficiency under rising CO2.

This work contributes to the planetary boundary simulator currently funded by the Volkswagen Foundation.