Model Documentation - WITNESS - Revision history

Mathijs Harmsen at 15:27, 21 July 2025

2025-07-21T15:27:41Z

← Older revision		Revision as of 17:27, 21 July 2025
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	Please check [https:///www.witness4climate.org/events/ here] for next sessions and registration.		Please check [https:///www.witness4climate.org/events/ here] for next sessions and registration.


			== Table of contents ==

			=== [[Model scope and methods - WITNESS\|Model scope and methods]] ===

			* '''[[Model concept, solver and details - WITNESS\|Model concept, solver and details]]'''
			* '''[[Temporal dimension - WITNESS\|Temporal dimension]]'''
			* '''[[Spatial dimension - WITNESS\|Spatial dimension]]'''
			* '''[[Policy - WITNESS\|Policy]]'''

			=== [[Socio-economic drivers - WITNESS\|Socio-economic drivers]] ===

			* '''[[Population - WITNESS\|Population]]'''
			* '''[[Economic activity - WITNESS\|Economic activity]]'''

			=== [[Macro-economy - WITNESS\|Macro-economy]] ===

			* '''[[Production system and representation of economic sectors - WITNESS\|Production system and representation of economic sectors]]'''
			* '''[[Capital and labour markets - WITNESS\|Capital and labour markets]]'''
			* '''[[Monetary instruments - WITNESS\|Monetary instruments]]'''
			* '''[[Trade - WITNESS\|Trade]]'''
			* '''[[Technological change - WITNESS\|Technological change]]'''

			=== [[Energy - WITNESS\|Energy]] ===

			* '''[[Energy resource endowments - WITNESS\|Energy resource endowments]]'''
			** [[Fossil energy resources - WITNESS\|Fossil energy resources]]
			** [[Uranium and other fissile resources - WITNESS\|Uranium and other fissile resources]]
			** [[Bioenergy - WITNESS\|Bioenergy]]
			** [[Non-biomass renewables - WITNESS\|Non-biomass renewables]]

			* '''[[Energy conversion - WITNESS\|Energy conversion]]'''
			** [[Electricity - WITNESS\|Electricity]]
			** [[Heat - WITNESS\|Heat]]
			** [[Gaseous fuels - WITNESS\|Gaseous fuels]]
			** [[Liquid fuels - WITNESS\|Liquid fuels]]
			** [[Solid fuels - WITNESS\|Solid fuels]]
			** [[Grid, pipelines and other infrastructure - WITNESS\|Grid, pipelines and other infrastructure]]
			** [[Energy end-use - WITNESS\|Energy end-use]]
			** [[Transport - WITNESS\|Transport]]
			** [[Residential and commercial sectors - WITNESS\|Residential and commercial sectors]]
			** [[Industrial sector - WITNESS\|Industrial sector]]
			** [[Other end-use - WITNESS\|Other end-use]]

			* '''[[Energy demand - WITNESS\|Energy demand]]'''
			* '''[[Technological change in energy - WITNESS\|Technological change in energy]]'''

			=== [[Land-use - WITNESS\|Land-use]] ===

			* '''[[Agriculture - WITNESS\|Agriculture]]'''
			* '''[[Forestry - WITNESS\|Forestry]]'''
			* '''[[Land-use change - WITNESS\|Land-use change]]'''
			* '''[[Bioenergy land-use - WITNESS\|Bioenergy land-use]]'''
			* '''[[Other land-use - WITNESS\|Other land-use]]'''
			* '''[[Agricultural demand - WITNESS\|Agricultural demand]]'''
			* '''[[Technological change in land-use - WITNESS\|Technological change in land-use]]'''
			=== [[Emissions - WITNESS\|Emissions]] ===
			* '''[[GHGs - WITNESS\|GHGs]]'''
			* '''[[Pollutants and non-GHG forcing agents - WITNESS\|Pollutants and non-GHG forcing agents]]'''
			* '''[[Carbon dioxide removal (CDR) options - WITNESS\|Carbon dioxide removal (CDR) options]]'''

			=== [[Climate - WITNESS\|Climate]] ===
			* '''[[Modelling of climate indicators - WITNESS\|Modelling of climate indicators ]]'''
			* '''[[Climate damages, temperature changes - WITNESS\|Climate damages, temperature changes ]]'''
			=== [[Non-climate sustainability dimension - WITNESS\|Non-climate sustainability dimension]] ===

			* '''[[Air pollution and health - WITNESS\|Air pollution and health]]'''
			* '''[[Water - WITNESS\|Water]]'''
			* '''[[Other materials - WITNESS\|Other materials]]'''
			* '''[[Other sustainability dimensions - WITNESS\|Other sustainability dimensions]]'''

			=== [[Appendices - WITNESS\|Appendices]] ===
			* '''[[Mathematical model description - WITNESS\|Mathematical model description]]'''
			* '''[[Data - WITNESS\|Data]]'''

			=== [[References - WITNESS\|References]] ===

Thierry Chevalier at 09:44, 26 December 2024

2024-12-26T09:44:46Z

← Older revision		Revision as of 11:44, 26 December 2024
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	The global structure of WITNESS is often presented using this picture		The global structure of WITNESS is often presented using this picture (Water not well implemented yet despite shown here) :

	[[File:WITNESS Overview Small.png\|alt=WITNESS overview]]		[[File:WITNESS Overview Small.png\|alt=WITNESS overview]]

Thierry Chevalier: /* Model presentation */

2024-12-26T09:37:39Z

Model presentation

← Older revision		Revision as of 11:37, 26 December 2024
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	WITNESS is an open source Integrated Assessment Model [[wikipedia:Software framework\|software framework]] - which means it's can be used as an application ready to use as is, or a toolset you can use, complete, customize or overload.		WITNESS is an open source Integrated Assessment Model [[wikipedia:Software framework\|software framework]] - which means it's can be used as an application ready to use as is, or a toolset you can use, complete, customize or overload.

	It can be used to explore potential future pathways for greenhouse gas emissions under different policy scenarios, assess how different levels of global warming will affect natural and human systems, identify the most cost-effective strategies producing energy while reducing emissions, analyze how to transition from fossil fuels to renewable energy sources while ensuring energy security and economic stability, evaluate the potential impacts of specific climate policies (e.g., carbon pricing, renewable energy incentives impact on emissions, economic growth~~, and social equity~~), determine the role of emerging technologies such as carbon capture and storage or advanced nuclear in achieving climate goals…		It can be used to explore potential future pathways for greenhouse gas emissions under different policy scenarios, assess how different levels of global warming will affect natural and human systems, identify the most cost-effective strategies producing energy while reducing emissions, analyze how to transition from fossil fuels to renewable energy sources while ensuring energy security and economic stability, evaluate the potential impacts of specific climate policies (e.g., carbon pricing or renewable energy incentives impact on emissions or economic growth), determine the role of emerging technologies such as carbon capture and storage or advanced nuclear in achieving climate goals…

	Its cooperative study setup and analysis capabilities also allow WITNESS to enhance cooperation to achieve global climate targets within a group of "coopetitors".		Its cooperative study setup and analysis capabilities also allow WITNESS to enhance cooperation to achieve global climate targets within a group of "coopetitors".

Thierry Chevalier at 09:05, 26 December 2024

2024-12-26T09:05:46Z

← Older revision		Revision as of 11:05, 26 December 2024
Line 9:		Line 9:
	WITNESS is an open source Integrated Assessment Model [[wikipedia:Software framework\|software framework]] - which means it's can be used as an application ready to use as is, or a toolset you can use, complete, customize or overload.		WITNESS is an open source Integrated Assessment Model [[wikipedia:Software framework\|software framework]] - which means it's can be used as an application ready to use as is, or a toolset you can use, complete, customize or overload.

	It's built on a powerful open source cooperative simulation platform called [https://www.witness4climate.org/sostrades-3/ SoSTrades], and uses [[wikipedia:Multidisciplinary design optimization#:~:text=Multi-disciplinary design optimization (MDO) is a field of,solve design problems incorporating a number of disciplines.\|multi-disciplinary analysis and optimization (MDAO)]] library called [https://gemseo.readthedocs.io/en/stable// GEMSEO].		It can be used to explore potential future pathways for greenhouse gas emissions under different policy scenarios, assess how different levels of global warming will affect natural and human systems, identify the most cost-effective strategies producing energy while reducing emissions, analyze how to transition from fossil fuels to renewable energy sources while ensuring energy security and economic stability, evaluate the potential impacts of specific climate policies (e.g., carbon pricing, renewable energy incentives impact on emissions, economic growth, and social equity), determine the role of emerging technologies such as carbon capture and storage or advanced nuclear in achieving climate goals…

			Its cooperative study setup and analysis capabilities also allow WITNESS to enhance cooperation to achieve global climate targets within a group of "coopetitors".


			WITNESS is built on a powerful open source cooperative simulation platform called [https://www.witness4climate.org/sostrades-3/ SoSTrades], and uses [[wikipedia:Multidisciplinary design optimization#:~:text=Multi-disciplinary design optimization (MDO) is a field of,solve design problems incorporating a number of disciplines.\|multi-disciplinary analysis and optimization (MDAO)]] library called [https://gemseo.readthedocs.io/en/stable// GEMSEO].

	This leading edge simulation base allow using the framework to set up and solve a large range of problems, be it in the pure IAM ecosystem area or deriving IAM scenarios/results for various applications such as evaluation of physical risks, optimization of ecosystem energy migration, or assets portfolio valuation…		This leading edge simulation base allow using the framework to set up and solve a large range of problems, be it in the pure IAM ecosystem area or deriving IAM scenarios/results for various applications such as evaluation of physical risks, optimization of ecosystem energy migration, or assets portfolio valuation…

Thierry Chevalier at 15:45, 23 December 2024

2024-12-23T15:45:11Z

← Older revision		Revision as of 17:45, 23 December 2024
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	The initial motivations to code "Yet Another IAM", a were - in that order :		The initial motivations to code "Yet Another IAM", a were - in that order :

	# to properly take into account energy-macroeconomy coupling, which was very well highlighted as problematic in current scenarios in a [https://www.carbone4.com/lancement-iris-initiative/ document from Carbon4], and well synthetized in the World GDP vs World energy production diagram it contains showing how most IAM predictions represent a sudden and abrupt change from decades of correlation between these 2 quantities. ~~This is something the energy-economy coupling estimate well in WITNESS as shown for example in the following studies~~		# to properly take into account energy-macroeconomy coupling, which was very well highlighted as problematic in current scenarios in a [https://www.carbone4.com/lancement-iris-initiative/ document from Carbon4], and well synthetized in the World GDP vs World energy production diagram it contains showing how most IAM predictions represent a sudden and abrupt change from decades of correlation between these 2 quantities.
	~~[[File:Study319-GDPvsEnergy-IEAvsWITNESS.png\|alt=Study319-GDPvsEnergy-IEAvsWITNESS]]~~
	# to properly add and couple an endogenous population model. Population is exogeneous in most models whereas climate impact on population and increase of pandemic rates with pressure on land could have significant economic impact- as demonstrated by impact of SARS-CoV-1, or measured productivity losses during recent heatwaves		# to properly add and couple an endogenous population model. Population is exogeneous in most models whereas climate impact on population and increase of pandemic rates with pressure on land could have significant economic impact- as demonstrated by impact of SARS-CoV-1, or measured productivity losses during recent heatwaves
	# to build an open and cooperative basis for a modular IAM that would be easy to extend and scale, thanks to re-using in the IAM area the leading edge complex system of systems simulation techniques that initial authors were experts at using in aerospace sector (including but not limited to MBSE and MDAO) - with the ability to reliably manage very large amount of models and automating handling of interactions and feedback loops and avoid the simulation constraints hampering modeling intend.		# to build an open and cooperative basis for a modular IAM that would be easy to extend and scale, thanks to re-using in the IAM area the leading edge complex system of systems simulation techniques that initial authors were experts at using in aerospace sector (including but not limited to MBSE and MDAO) - with the ability to reliably manage very large amount of models and automating handling of interactions and feedback loops and avoid the simulation constraints hampering modeling intend.

Thierry Chevalier at 15:43, 23 December 2024

2024-12-23T15:43:15Z

← Older revision		Revision as of 17:43, 23 December 2024
Line 16:		Line 16:
	The initial motivations to code "Yet Another IAM", a were - in that order :		The initial motivations to code "Yet Another IAM", a were - in that order :

	# to properly take into account energy-macroeconomy coupling, which was very well highlighted as problematic in current scenarios in a [https://www.carbone4.com/lancement-iris-initiative/ document from Carbon4], and well synthetized in the World GDP vs World energy production diagram it contains showing how most IAM predictions represent a sudden and abrupt change from decades of correlation between these 2 quantities		# to properly take into account energy-macroeconomy coupling, which was very well highlighted as problematic in current scenarios in a [https://www.carbone4.com/lancement-iris-initiative/ document from Carbon4], and well synthetized in the World GDP vs World energy production diagram it contains showing how most IAM predictions represent a sudden and abrupt change from decades of correlation between these 2 quantities. This is something the energy-economy coupling estimate well in WITNESS as shown for example in the following studies
			[[File:Study319-GDPvsEnergy-IEAvsWITNESS.png\|alt=Study319-GDPvsEnergy-IEAvsWITNESS]]
	# to properly add and couple an endogenous population model. Population is exogeneous in most models whereas climate impact on population and increase of pandemic rates with pressure on land could have significant economic impact- as demonstrated by impact of SARS-CoV-1, or measured productivity losses during recent heatwaves		# to properly add and couple an endogenous population model. Population is exogeneous in most models whereas climate impact on population and increase of pandemic rates with pressure on land could have significant economic impact- as demonstrated by impact of SARS-CoV-1, or measured productivity losses during recent heatwaves
	# to build an open and cooperative basis for a modular IAM that would be easy to extend and scale, thanks to re-using in the IAM area the leading edge complex system of systems simulation techniques that initial authors were experts at using in aerospace sector (including but not limited to MBSE and MDAO) - with the ability to reliably manage very large amount of models and automating handling of interactions and feedback loops and avoid the simulation constraints hampering modeling intend.		# to build an open and cooperative basis for a modular IAM that would be easy to extend and scale, thanks to re-using in the IAM area the leading edge complex system of systems simulation techniques that initial authors were experts at using in aerospace sector (including but not limited to MBSE and MDAO) - with the ability to reliably manage very large amount of models and automating handling of interactions and feedback loops and avoid the simulation constraints hampering modeling intend.

Thierry Chevalier at 15:35, 23 December 2024

2024-12-23T15:35:21Z

← Older revision		Revision as of 17:35, 23 December 2024
Line 20:		Line 20:
	# to build an open and cooperative basis for a modular IAM that would be easy to extend and scale, thanks to re-using in the IAM area the leading edge complex system of systems simulation techniques that initial authors were experts at using in aerospace sector (including but not limited to MBSE and MDAO) - with the ability to reliably manage very large amount of models and automating handling of interactions and feedback loops and avoid the simulation constraints hampering modeling intend.		# to build an open and cooperative basis for a modular IAM that would be easy to extend and scale, thanks to re-using in the IAM area the leading edge complex system of systems simulation techniques that initial authors were experts at using in aerospace sector (including but not limited to MBSE and MDAO) - with the ability to reliably manage very large amount of models and automating handling of interactions and feedback loops and avoid the simulation constraints hampering modeling intend.

	We decided to develop a Stock Flow Coherent model, as it seems they are the only models that succeeds in back-testing evaluations (cf [https://chair-energy-prosperity.org/wp-content/uploads/2024/10/WP2024-les-modeles-IAMs-et-leurs-limites.pdf/ "Les modèles IAMs et leurs limites" A.Grandjean 2024]).		We decided to develop a Stock Flow Coherent model, as it seems they are the only models that succeeds in back-testing evaluations (cf [https://chair-energy-prosperity.org/wp-content/uploads/2024/10/WP2024-les-modeles-IAMs-et-leurs-limites.pdf "Les modèles IAMs et leurs limites" A.Grandjean 2024]).

Thierry Chevalier: _ changed in + in some links... again !!!

2024-12-23T15:32:30Z

_ changed in + in some links... again !!!

← Older revision		Revision as of 17:32, 23 December 2024
Line 21:		Line 21:

	We decided to develop a Stock Flow Coherent model, as it seems they are the only models that succeeds in back-testing evaluations (cf [https://chair-energy-prosperity.org/wp-content/uploads/2024/10/WP2024-les-modeles-IAMs-et-leurs-limites.pdf/ "Les modèles IAMs et leurs limites" A.Grandjean 2024]).		We decided to develop a Stock Flow Coherent model, as it seems they are the only models that succeeds in back-testing evaluations (cf [https://chair-energy-prosperity.org/wp-content/uploads/2024/10/WP2024-les-modeles-IAMs-et-leurs-limites.pdf/ "Les modèles IAMs et leurs limites" A.Grandjean 2024]).



	The global structure of WITNESS is often presented using this picture		The global structure of WITNESS is often presented using this picture

	[[File:WITNESS Overview Small.png\|alt=WITNESS overview]]		[[File:WITNESS Overview Small.png\|alt=WITNESS overview]]



	but the detailed coupling structure is depending of the problem you solve, coupling being handled automatically.		but the detailed coupling structure is depending of the problem you solve, coupling being handled automatically.

	As an example, [https:///www.witness4climate.org/files/WITNESSCouplings/~~WITNESS Val Full Optim new x0 converged Eval interface diagram~~.sozi.html here] is a map of a typical WITNESS full couplings.		As an example, [https:///www.witness4climate.org/files/WITNESSCouplings/WITNESS_Val_Full_Optim_new_x0_converged_Eval_interface_diagram.sozi.html here] is a map of a typical WITNESS full couplings.

Thierry Chevalier at 15:29, 23 December 2024

2024-12-23T15:29:01Z

← Older revision		Revision as of 17:29, 23 December 2024
Line 24:		Line 24:

	The global structure of WITNESS is often presented using this picture		The global structure of WITNESS is often presented using this picture
	[[File:WITNESS Overview Small.png\|alt=~~WITNESS overview\|thumb\|WITNESS overview]]~~		[[File:WITNESS Overview Small.png\|alt=WITNESS overview]]
	~~[[File:WITNESS Overview Small.png\|alt=WITNESS overview\|thumb\|~~WITNESS overview]]

Thierry Chevalier at 15:27, 23 December 2024

2024-12-23T15:27:20Z

← Older revision		Revision as of 17:27, 23 December 2024
Line 20:		Line 20:
	# to build an open and cooperative basis for a modular IAM that would be easy to extend and scale, thanks to re-using in the IAM area the leading edge complex system of systems simulation techniques that initial authors were experts at using in aerospace sector (including but not limited to MBSE and MDAO) - with the ability to reliably manage very large amount of models and automating handling of interactions and feedback loops and avoid the simulation constraints hampering modeling intend.		# to build an open and cooperative basis for a modular IAM that would be easy to extend and scale, thanks to re-using in the IAM area the leading edge complex system of systems simulation techniques that initial authors were experts at using in aerospace sector (including but not limited to MBSE and MDAO) - with the ability to reliably manage very large amount of models and automating handling of interactions and feedback loops and avoid the simulation constraints hampering modeling intend.

	We decided to develop a Stock Flow Coherent model, as it seems they are the only models that succeeds in back-testing evaluations (cf [[/chair-energy-prosperity.org/wp-content/uploads/2024/10/WP2024-les-modeles-IAMs-et-leurs-limites.pdf\|"Les modèles IAMs et leurs limites" A.Grandjean 2024]]).		We decided to develop a Stock Flow Coherent model, as it seems they are the only models that succeeds in back-testing evaluations (cf [https://chair-energy-prosperity.org/wp-content/uploads/2024/10/WP2024-les-modeles-IAMs-et-leurs-limites.pdf/ "Les modèles IAMs et leurs limites" A.Grandjean 2024]).

← Older revision		Revision as of 17:27, 21 July 2025
Line 73:		Line 73:

	Please check [https:///www.witness4climate.org/events/ here] for next sessions and registration.		Please check [https:///www.witness4climate.org/events/ here] for next sessions and registration.


			== Table of contents ==

			=== [[Model scope and methods - WITNESS\|Model scope and methods]] ===

			* '''[[Model concept, solver and details - WITNESS\|Model concept, solver and details]]'''
			* '''[[Temporal dimension - WITNESS\|Temporal dimension]]'''
			* '''[[Spatial dimension - WITNESS\|Spatial dimension]]'''
			* '''[[Policy - WITNESS\|Policy]]'''

			=== [[Socio-economic drivers - WITNESS\|Socio-economic drivers]] ===

			* '''[[Population - WITNESS\|Population]]'''
			* '''[[Economic activity - WITNESS\|Economic activity]]'''

			=== [[Macro-economy - WITNESS\|Macro-economy]] ===

			* '''[[Production system and representation of economic sectors - WITNESS\|Production system and representation of economic sectors]]'''
			* '''[[Capital and labour markets - WITNESS\|Capital and labour markets]]'''
			* '''[[Monetary instruments - WITNESS\|Monetary instruments]]'''
			* '''[[Trade - WITNESS\|Trade]]'''
			* '''[[Technological change - WITNESS\|Technological change]]'''

			=== [[Energy - WITNESS\|Energy]] ===

			* '''[[Energy resource endowments - WITNESS\|Energy resource endowments]]'''
			** [[Fossil energy resources - WITNESS\|Fossil energy resources]]
			** [[Uranium and other fissile resources - WITNESS\|Uranium and other fissile resources]]
			** [[Bioenergy - WITNESS\|Bioenergy]]
			** [[Non-biomass renewables - WITNESS\|Non-biomass renewables]]

			* '''[[Energy conversion - WITNESS\|Energy conversion]]'''
			** [[Electricity - WITNESS\|Electricity]]
			** [[Heat - WITNESS\|Heat]]
			** [[Gaseous fuels - WITNESS\|Gaseous fuels]]
			** [[Liquid fuels - WITNESS\|Liquid fuels]]
			** [[Solid fuels - WITNESS\|Solid fuels]]
			** [[Grid, pipelines and other infrastructure - WITNESS\|Grid, pipelines and other infrastructure]]
			** [[Energy end-use - WITNESS\|Energy end-use]]
			** [[Transport - WITNESS\|Transport]]
			** [[Residential and commercial sectors - WITNESS\|Residential and commercial sectors]]
			** [[Industrial sector - WITNESS\|Industrial sector]]
			** [[Other end-use - WITNESS\|Other end-use]]

			* '''[[Energy demand - WITNESS\|Energy demand]]'''
			* '''[[Technological change in energy - WITNESS\|Technological change in energy]]'''

			=== [[Land-use - WITNESS\|Land-use]] ===

			* '''[[Agriculture - WITNESS\|Agriculture]]'''
			* '''[[Forestry - WITNESS\|Forestry]]'''
			* '''[[Land-use change - WITNESS\|Land-use change]]'''
			* '''[[Bioenergy land-use - WITNESS\|Bioenergy land-use]]'''
			* '''[[Other land-use - WITNESS\|Other land-use]]'''
			* '''[[Agricultural demand - WITNESS\|Agricultural demand]]'''
			* '''[[Technological change in land-use - WITNESS\|Technological change in land-use]]'''
			=== [[Emissions - WITNESS\|Emissions]] ===
			* '''[[GHGs - WITNESS\|GHGs]]'''
			* '''[[Pollutants and non-GHG forcing agents - WITNESS\|Pollutants and non-GHG forcing agents]]'''
			* '''[[Carbon dioxide removal (CDR) options - WITNESS\|Carbon dioxide removal (CDR) options]]'''

			=== [[Climate - WITNESS\|Climate]] ===
			* '''[[Modelling of climate indicators - WITNESS\|Modelling of climate indicators ]]'''
			* '''[[Climate damages, temperature changes - WITNESS\|Climate damages, temperature changes ]]'''
			=== [[Non-climate sustainability dimension - WITNESS\|Non-climate sustainability dimension]] ===

			* '''[[Air pollution and health - WITNESS\|Air pollution and health]]'''
			* '''[[Water - WITNESS\|Water]]'''
			* '''[[Other materials - WITNESS\|Other materials]]'''
			* '''[[Other sustainability dimensions - WITNESS\|Other sustainability dimensions]]'''

			=== [[Appendices - WITNESS\|Appendices]] ===
			* '''[[Mathematical model description - WITNESS\|Mathematical model description]]'''
			* '''[[Data - WITNESS\|Data]]'''

			=== [[References - WITNESS\|References]] ===