Thread by @Limits2Growth

To get rid of the CO2 in 24 years using negative emissions would require a system with a capacity (measured in Gt/year) 12 times our current annual rate of oil consumption. The claim by scientists that negative emissions could be a viable path doesn't seem practical.

We applied a basic understanding of levels and rates and arithmetic to formulate this hypothesis. These are key concepts in system dynamics.

The levels are the accumulations within a system. The rates represent the system activity which causes a particular level to change.

We used a simple model with assumptions. This is a formal model. We can describe it and have a rational debate about its validity. It leads to important conclusions but paradoxically the only thing we can be certain of is that the model is wrong.

All models are wrong!

By the way, here is a more accurate simulation of CO2 accumulation dynamics!

…dsworldclimate.climateinteractive.org

If all models are wrong, why should we use them?

Well, first, some modeling frameworks are simply better in describing the structure and dynamic behavior of complex non-linear systems. Also, what matters is the modeling process and how we use the models. Models evolve.

Second, humans have a poor intuitive understanding of levels, rates, delays, inertia, conservation of mass and energy. Besides, many judgments and decisions are quick and dirty, based on heuristics and biases. Intrinsic aspects of complex systems amplify these weaknesses.

Consider one of the simplest systems one can think of. The glorious bathtub.

Almost anyone can describe how the bathtub works. And even operate it.