DICEModel

Julia/JuMP port of the Nordhaus' DICE (Dynamic Integrated Climate-Economy model) model.

This package currently implements the DICE2023-b-4-3-10.gms gams version.

This program and output is not the original Barrage/Nordhaus version, which is currently only available in GAMS.

While DICEModel.jl is implemented in Julia it can easily be used in Python or R using the JuliaCall (Python) and JuliaCall (R) packages respectively.

Goals of this package

Provide a practical, full open-source (using all open-source tools) implementation of the latest version of the DICE model, keeping the model readable, compact and as close as possible to the original (GAMS) code.

This package provides two functions:

• run_dice_scenario(scenario_name) [browse code - documentation ] : runs one of the "official" 10 scenarios;
• run_dice(;optimizer,bounds,kwargs...) [browse code - documentation] : run DICE with custom solver engine (and eventually options), custom variable constraints (bounds) or custom parameters (see Parameters).

In both cases the output (results) is a named tuple. Use keys(results) to find the available information (or just look at the source code) and results.VARIABLEX to obtain the values.

A summary of the main results is available on this page.

Example

using Pkg
Pkg.activate(@__DIR__)
Pkg.add(["DICEModel","Plots"]) # run only once, then comment out
using DICEModel, Plots

# CB Optimal scenario...
res_cbopt    = run_dice_scenario("cbopt")

# Base scenario...
res_base    = run_dice_scenario("base")

# Paris "extended" scenario...
tidx = 1:81
# upper limit to emissions mitigation rate
miuup = @. min( 0.05 + 0.04*(tidx-1) - 0.01*max(0,tidx-5)  ,1.00) 
res_parisext = run_dice(miuup = miuup) # or simply: run_dice_scenario("parisext")

# Max 2 °C scenario...
res_t2c = run_dice(bounds = Dict("TATM"=>("<=",2.0))) # or simply: run_dice_scenario("t2c")

# Plots
times = res_cbopt.times

# CO2 emissions plot...
plot(times[1:11],res_cbopt.ECO2[1:11],ylim=(0,70), title="CO₂ emissions",ylabel="GtCO₂/yr",label="C/B optimal", color=:blue4, markershape=:circle, markercolor=:white)
plot!(times[1:11],res_base.ECO2[1:11], label="Base", colour=:goldenrod3, markershape=:circle, markercolor=:goldenrod3)
plot!(times[1:11],res_parisext.ECO2[1:11], label="Paris ext", colour=:red, linestyle=:dash)
plot!(times[1:11],res_t2c.ECO2[1:11], label="T < 2 °C", colour=:green, markershape=:cross, markercolor=:green)

# Carbon price plot...
plot(times[1:9],res_cbopt.CPRICE[1:9],ylim=(0,300), title="Carbon price",ylabel="2019\$ / t tCO₂",label="C/B optimal", color=:blue4, markershape=:circle, markercolor=:white)
plot!(times[1:9],res_base.CPRICE[1:9], label="Base", colour=:goldenrod3, markershape=:circle, markercolor=:goldenrod3)
plot!(times[1:9],res_parisext.CPRICE[1:9], label="Paris ext", colour=:red, linestyle=:dash)
plot!(times[1:9],res_t2c.CPRICE[1:9], label="T < 2 °C", colour=:green, markershape=:cross, markercolor=:green)

Other packages or implementations of the DICE model

• DuBois Julia implementation: No updates to DICE 2023, code divided in many pieces
• MIMI framework based implementations (eg. v2016 or v2016R2): Not updated to DICE 2023, code divided in many pieces (different implementation and solver structure)
• olugovoy implementation in various languages (Julia included): No updates, code very "R like"
• Benet and Akshay MATLAB implementation : Still require MATLAB, code not readable/compact as GAMS or JuMP
• Nie and Welch Python implementation : Code not readable/compact as GAMS or JuMP

Licence

The licence of the original GAMS code has never being specified. The Julia port itself (and only that) is MIT.