System Dynamics in Climate Change Mitigation Rachel Freeman (Tyndall Centre for Climate Change Research, University of Manchester) Presented at: UK Chapter of the SD Society Network Event 5 th December 2017
Welcome ▪ Housekeeping ▪ The purpose of today – Explore the role of system dynamics in climate change mitigation – Learn (more) about system dynamics – Learn (more) about climate change mitigation ▪ Why here? – Tyndall Manchester is one of only a few specialist academic centres working in climate change mitigation – Climate change mitigation is by nature a systemic problem – SD is not in common use here, but it could be! 2
Agenda 13:00 – 13:15 Arrivals, lunch available Welcome. Overview of climate change mitigation, introduction 13:15 – 13.35 Rachel Freeman to SD, use of SD in climate mitigation Martin Reynolds, Open 13:35 – 14:00 A critical systems view of sustainability University Frank Boons, University 14:00 – 14:25 Circular economy and climate change – a social science view of Manchester Daniel Schein, 14:25 – 14:50 SD modelling of the environmental impact of digital media University of Bristol 14:50 – 15:05 Refreshment Break John Broderick, 15:05 – 15:20 University of Manchester Using C-Roads to teach about climate change mitigation Plenary discussion: *Examples of climate change mitigation 15:20 – 15:35 *Causal issues common to the examples – critical systems Panel concepts, social science concepts, technology, economy, others… 15:35 – 15:45 Rachel Freeman Introduction to group model building 15:45 – 16:30 Group model building session in small groups, refreshments available 16:30 – 16:45 Presentations from the small groups 3 16:45 – 17:00 Plenary – general discussion and wrap up
The Problem Space – Climate Change Mitigation
The Carbon Cycle ▪ The carbon cycle links global climate with the response of local natural systems to atmosphere and climate ▪ Anthropogenic GHG emissions arise from fossil fuel based energy systems, agriculture and direct land use change – disrupting the previously stable carbon cycle of the Holocene 5
Climate Change Trajectory
Climate Change Impacts IPCC. (2014). Climate Change 2014 Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Inter- governmental Panel on Climate Change 7
Climate Change Mitigation ▪ Interventions that reduce anthropogenic greenhouse gas (GHG) emissions to abate climate change and its impacts ▪ Mitigation is a relatively new field of study/practice with many uncertainties: – Its characteristics as a problem space (what systemicity exists?) – Why mitigation progress is so difficult – Real/perceived tensions between human well-being and mitigation – What disciplines and theories are needed to unpick the problem space: engineering, social science, physical sciences, economics, systems science… 8
Mitigation Actions 1. Fossil fuel based energy systems – Transition away from fossil fuels to achieve net zero GHG emissions in buildings, transport, industry, agriculture, energy systems 2. Agriculture – Healthy soils, reduced toxic impact from chemicals, reduced water use – Reduced livestock production and waste 3. Direct land use change – Urban planning (e.g. higher density living, making space for nature) – Ecosystem preservation, restoration The circular economy could help mitigate all types of emissions 9
System Dynamics as Part of the Solution Space
System Dynamics ▪ SD is ‘The use of informal maps and formal models with computer simulation to uncover and understand endogenous sources of system behaviour’ 1 ▪ In SD understanding of structure and its relation to system behaviour is crucial: ‘The level -rate-feedback structure in system dynamics is indeed the fundamental and universal structure of real social and physical systems’ 2 ▪ SD uses simulation modelling since ‘the temporal and spatial boundaries of our mental models are dynamically deficient, omitting feedbacks, time delays, accumulations, and nonlinearities’ 3 1 G. P. Richardson, “Reflections on the foundations of system dynamics,” System Dynamics Review , vol. 27, no. 3, pp. 219 – 243, 2011 2 J. W. Forrester, “System dynamics , systems thinking , and soft OR,” System Dynamics Review , vol. 10, no. 2 – 3, pp. 245 – 256, 1994. 3 J. Sterman, Business dynamics : systems thinking and modeling for a complex world . Boston ; London: Irwin/McGraw-Hill, 2000 11
Modelling Causal Links + B Positive Causation/Influence: As A increases (or decreases) B increases (or decreases) A - D Negative Causation/Influence: As C increases (or decreases) D decreases (or increases) C F Causation/Influence with Delay: E causes an increase/decrease in F after some delay E Balancing Loop: goal seeking feedback that B counteracts and limits change Reinforcing Loop: amplification feedback that R grows indefinitely until disturbed 12
Causation and Feedback Incorrect Correct murder rate ice cream sales + + + murder rate ice cream sales average temperature - death rate population B birth rate R + - Births/population/year average fractional birth lifetime rate Causal Loop Diagrams are “visual representations of the dynamic influences and inter- relationships that exist among a collection of variables” (Spector et al. 2001) 13
Modelling stocks and flows ▪ “Stocks” or “levels” represent accumulations of things ▪ “Rates” or “flows” define the rate at which accumulating or draining processes move things into or out of the stocks ▪ “Auxiliaries” can influence flows but do not directly influence stocks – Constants (can represent exogenous influences on the system) – Variables calculated from stock values or auxiliaries fractional fractional birth death rate rate R B + + + + Population - + births deaths 14
Examples of SD in CC Mitigation 1 ▪ Stepp et al.: ‘ Qualitative framework for understanding the direct and indirect impacts of GHG reduction policies aimed at the transportation sector…identify important feedback loops that allow for the identification and discussion of unintended consequences, policy resistances, and policy synergies’. Stepp, M. D., Winebrake, J. J., Hawker, J. S., & Skerlos, S. J. (2009). Greenhouse gas mitigation policies and the transportation sector: The role of feedback effects on policy effectiveness. Energy Policy , 37 (7), 2774 – 2787 ▪ Anand et al.: ‘Mitigation strategies for curtailing CO2 emissions from the cement sector. Emissions are dependent on many interrelated variables, viz. population and GDP growth rate, cement demand and production, clinker consumption and energy use. A scenario with population stabilisation, structural shifting, 25% renewable energy sources, energy efficient processes and waste heat recovery could reduce CO2 emissions by 42% in the year 2020’. Anand, S., Vrat, P., & Dahiya, R. P. (2006). Application of a system dynamics approach for assessment and mitigation of CO2 emissions from the cement industry. Journal of Environmental Management , 79 (4), 383 – 98 15
Example page from World3 (LTG) <land yield> <marginal productivity marginal productivity of agricultural inputs> of land development social discount fraction of agricultural inputs allocated to land development cost per hectare table development table fraction of agricultural inputs development cost potentially arable land total allocated to land development per hectare <total agricultural investment> initial arable land initial urban and industrial land initial potentially arable land Urban and Potentially Arable Land Industrial Arable Land Land land development land removal for urban and industrial use rate average life of land normal <land life policy land erosion rate implementation time s> average life of land urban and industrial urban and industrial <Time> land development time land life multiplier land required from land yield <land life multiplier from land yield 2> urban and industrial <population> <one year> <land life multiplier from land yield 1> land required per capita initial land fertility urban and industrial land <industrial output per capita> required per capita table <persistent pollution Land Fertility index> <GDP pc unit> land fertility land fertility land fertility regeneration degredation degredation rate table land fertility <fraction of agricultural inputs inherent land fertility land fertility regeneration time for land maintenance> degredation rate 16 land fertility regeneration time table
World3 BAU Outputs 17
Carbon Cycle as SD Model + human population R1 + human consumption of resources B2 + GHG in fossil fuels availability of natural direct negative fossil fuel systems services impacts on B1 use ecosystems rate of GHG emissions from + GHG from + fossil fuels agriculture B3 - + rate of GHG take Natural systems on level of up in ecosystems land and below atmospheric water greenhouse gases - + rate of rate of GHG ecosystem emissions from regeneration ecosystems - R2 climate change impacts threshold + 18 impacts multiplier (1.5, 2.0, 3-4 degrees) +
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