Abstract for: Towards a fully coupled Integrated Climate Assessment Model: FRIDA Version 0.1

We document FRIDA V0.1, a simple, box-model-type joint climate - IAM (Integrated Assessment Model), or World-Earth model, using the computational framework of System Dynamics. It places nature and humans on similar footing: both sides are extensively calibrated (back to 1980), and of similar complexity. The objective is to deliver to the international climate community a model that overcomes several key weaknesses of state-of-the-art Earth System Models (ESMs) and IAMs: limited level of connections from climate to human societies, lack of transparency into the models, limited understanding of uncertainty associated with model results, and limited scope for stakeholder engagement. These weaknesses can be mitigated by using the System Dynamics framework to its full extent, involving domain expertise from the climate research community. We will develop FRIDA in several steps. V0.1 focuses on the effects of climate-to-human feedbacks. The strongest impact of including those feedbacks is not that the rate of warming, nor the level of anthropogenic emissions, changes greatly. The greatest change is found in the global economy. Models run without feedbacks from the climate to human societies are, according to our study, likely to greatly underestimate the detrimental effect of climate change on the economy.