World environmental ImpacT aNd Economics ScenarioS
- Explore potential energy transition paths through simulation,
identify the most influential transition drivers - Jointly agree on a trajectory envelope,
engage a critical mass of actors to make it happen (self-fulfilling prophecy) - Estimate risk by measuring the difference between planned trajectory and worse ones
WITNESS is a framework to structure the problem following a system of systems approach, allowing to leverage numerical simulation methods and tools to build a complete world transition model.
Such a framework makes it possible to plug-in and connect best-in-class models from various origins, in order to assess various strategies in the context of possible energy, resources, climate or economy evolutions, collaboratively securing and combining various experts’ advices on strategies strengths or weaknesses, coverage or gaps of the various strategies.
Key coupling assumptions in WITNESS
“Labour without energy is a corpse; capital without energy is a sculpture.” Steve Keen
▪ Gross Domestic Product depends on capital, labour and net energy output (see here)
usable capital : capital needs to be fed with energy, for it to be able to produce output
maximum usable energy of capital : not able to absorb more energy that it is built for
productivity factor of capital : representing loss of productivity if minimum number of labour are not available
▪ Need to have a population model to properly create world scenarios (as in World3 model – see here)
labour : GDP depends on evolving population age distribution
population : impacted by climate change damage (extreme weather conditions, sea level rise, etc…)
amount of food available : evolves with climate change impact on productivity of agriculture and land usage
▪ Access to net energy production to properly feed production function (see here)
production technologies : needed to model resources impact and interdependencies in global energy production mix
production interdependencies : to solve net energy production computation
production investments in energy sector : linked to overall GDP as depending on economy evolutions
▪ Earth is a finite system with many resources boundaries reflected in the framework (e.g. copper, land use…)
resources consumption: tracked (e.g. energy, economy, agriculture…) & pitched against reserve estimations
capital : all assets, for instance factories, buildings, machines and so on
labour : employed population, changes depending on age distribution and population evolution.
net energy output: usable energy, removing from raw production, energy used to produce energy itself
WITNESS vs many existing Integrated Assessment Models
(from CarbonBrief “How ‘integrated assessment models’ are used to study climate change”)
