Source: Climate etc.
by David Wojick
The monster of all climate modeling efforts is the so-called Social Cost of Carbon (SCC). This involves what are called Integrated Assessment Models or IAMs. These models reflect the fact that, from a policy standpoint, the issue of climate change is simply an enormous environmental impact assessment.
An IAM begins with a CO2 emission model, then adds a climate change model, plus a physical damage-from-climate change model, followed by a global economic damage (from the physical damage) model. This complex combination of models is the ‘integration’ part.