diff --git a/Artifacts.toml b/Artifacts.toml
index 1bbe36cfbc9..0945016de4a 100644
--- a/Artifacts.toml
+++ b/Artifacts.toml
@@ -36,7 +36,14 @@ lazy = true
     [[earth_orography_60arcseconds.download]]
     sha256 = "eca66c0701d1c2b9e271742314915ffbf4a0fae92709df611c323f38e019966e"
     url = "https://caltech.box.com/shared/static/4asrxcgl6xsgenfcug9p0wkkyhtqilgk.gz"
-    
+
+[co2_dataset]
+git-tree-sha1 = "9c3bd05b68e820fceb43d130ce6b4e86ce788e4e"
+
+    [[co2_dataset.download]]
+    sha256 = "46923ec3e1f9028a11899c47e6b13d675d84daa9db2f37351a19ec9187f87865"
+    url = "https://caltech.box.com/shared/static/fuwajscgyblccy8y9aq01d0pgy91gwut.gz"
+
 [era5_cloud]
 git-tree-sha1 = "10742e0a2e343d13bb04df379e300a83402d4106"
 
diff --git a/NEWS.md b/NEWS.md
index 8970d52d75e..697287d11c6 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -5,20 +5,24 @@ Main
 -------
 
 
-v0.28.2
--------
 ### Features
 
-### Add van Leer class operator
+### Read CO2 from file
 
-Added a new vertical transport option `vanleer_limiter` (for tracer and energy variables)
-which uses methods described in Lin et al. (1994) to apply slope-limited upwinding. Adds
-operator
+`ClimaAtmos` now support using data from the Mauna Loa CO2 measurements to set
+CO2 concentration. This is currently only relevant for radiation transfer with
+RRTGMP.
 
-v0.28.1
+v0.28.2
 -------
 ### Features
 
+### Add van Leer class operator
+
+Added a new vertical transport option `vanleer_limiter` (for tracer and energy
+variables) which uses methods described in Lin et al. (1994) to apply
+slope-limited upwinding. Adds operator
+
 ### Read initial conditions from NetCDF files
 
 Added functionality to allow initial conditions to be overwritten by
diff --git a/calibration/experiments/gcm_driven_scm/model_config_diagnostic.yml b/calibration/experiments/gcm_driven_scm/model_config_diagnostic.yml
index 8026890f85a..5b109cb1749 100644
--- a/calibration/experiments/gcm_driven_scm/model_config_diagnostic.yml
+++ b/calibration/experiments/gcm_driven_scm/model_config_diagnostic.yml
@@ -25,6 +25,7 @@ z_elem: 60
 z_stretch: true
 dz_bottom: 30
 rad: allskywithclear
+co2_model: fixed
 insolation: "gcmdriven"
 dt: "100secs"
 t_end: "72hours"
diff --git a/calibration/experiments/gcm_driven_scm/model_config_prognostic.yml b/calibration/experiments/gcm_driven_scm/model_config_prognostic.yml
index ac8505fc78a..de79f10368d 100644
--- a/calibration/experiments/gcm_driven_scm/model_config_prognostic.yml
+++ b/calibration/experiments/gcm_driven_scm/model_config_prognostic.yml
@@ -25,6 +25,7 @@ z_elem: 60
 z_stretch: true
 dz_bottom: 30
 rad: allskywithclear
+co2_model: fixed
 insolation: "gcmdriven"
 perturb_initstate: false
 dt: "10secs"
diff --git a/calibration/test/model_config.yml b/calibration/test/model_config.yml
index d36b49d5162..9b0a7215651 100644
--- a/calibration/test/model_config.yml
+++ b/calibration/test/model_config.yml
@@ -8,6 +8,7 @@ output_dir: calibration_end_to_end_test
 output_default_diagnostics: false
 dt_rad: 6hours
 rad: clearsky
+co2_model: fixed
 diagnostics:
   - reduction_time: average
     short_name: rsut
diff --git a/config/default_configs/default_config.yml b/config/default_configs/default_config.yml
index 8028c8e78f8..5d3cd0789d7 100644
--- a/config/default_configs/default_config.yml
+++ b/config/default_configs/default_config.yml
@@ -289,6 +289,9 @@ restart_file:
 prescribe_ozone:
   help: "Prescribe time and spatially varying ozone from a file [`false` (default), `true`]"
   value: false
+co2_model:
+  help: "What CO2 concentration to use for RRTGMP. When fixed, it is set to 397.547 parts per million. Otherwise, it is read from the MaunaLoa measuraments. [`nothing` (default), `Fixed`, `MaunaLoa`]"
+  value: ~
 detect_restart_file:
   help: "When true, try finding a restart file and use it to restart the simulation. Only works with ActiveLink."
   value: false
diff --git a/config/gpu_configs/gpu_aquaplanet_dyamond_diag_1process.yml b/config/gpu_configs/gpu_aquaplanet_dyamond_diag_1process.yml
index 8ef339b47c1..1cddbf565a9 100644
--- a/config/gpu_configs/gpu_aquaplanet_dyamond_diag_1process.yml
+++ b/config/gpu_configs/gpu_aquaplanet_dyamond_diag_1process.yml
@@ -9,6 +9,7 @@ viscous_sponge: true
 moist: equil
 precip_model: 1M
 rad: allskywithclear
+co2_model: fixed
 idealized_insolation: false
 dt_rad: 1hours
 vert_diff: "DecayWithHeightDiffusion"
diff --git a/config/model_configs/aquaplanet_diagedmf.yml b/config/model_configs/aquaplanet_diagedmf.yml
index 65e8f1d36ec..d0ad1cc7236 100644
--- a/config/model_configs/aquaplanet_diagedmf.yml
+++ b/config/model_configs/aquaplanet_diagedmf.yml
@@ -10,6 +10,7 @@ viscous_sponge: true
 moist: equil
 surface_setup: DefaultMoninObukhov
 rad: allskywithclear
+co2_model: maunaloa
 insolation: "timevarying"
 dt_rad: 1hours
 dt_cloud_fraction: 1hours
diff --git a/config/model_configs/aquaplanet_progedmf.yml b/config/model_configs/aquaplanet_progedmf.yml
index a770e4ed443..cc23eb6155d 100644
--- a/config/model_configs/aquaplanet_progedmf.yml
+++ b/config/model_configs/aquaplanet_progedmf.yml
@@ -10,6 +10,7 @@ viscous_sponge: true
 moist: equil
 surface_setup: DefaultMoninObukhov
 rad: allskywithclear
+co2_model: fixed
 insolation: "timevarying"
 dt_rad: 1hours
 dt_cloud_fraction: 1hours
diff --git a/config/model_configs/diagnostic_edmfx_aquaplanet.yml b/config/model_configs/diagnostic_edmfx_aquaplanet.yml
index 01bf534cfed..bcef7014170 100644
--- a/config/model_configs/diagnostic_edmfx_aquaplanet.yml
+++ b/config/model_configs/diagnostic_edmfx_aquaplanet.yml
@@ -4,6 +4,7 @@ dz_bottom: 50.0
 rayleigh_sponge: true
 surface_setup: DefaultMoninObukhov
 rad: clearsky
+co2_model: fixed
 turbconv: diagnostic_edmfx
 implicit_diffusion: true
 approximate_linear_solve_iters: 2
diff --git a/config/model_configs/diagnostic_edmfx_aquaplanet_gpu.yml b/config/model_configs/diagnostic_edmfx_aquaplanet_gpu.yml
index dc988bb73cb..b2e62387b67 100644
--- a/config/model_configs/diagnostic_edmfx_aquaplanet_gpu.yml
+++ b/config/model_configs/diagnostic_edmfx_aquaplanet_gpu.yml
@@ -3,6 +3,7 @@ z_elem: 31
 dz_bottom: 50.0
 surface_setup: DefaultMoninObukhov
 rad: clearsky
+co2_model: fixed
 turbconv: diagnostic_edmfx
 implicit_diffusion: true
 approximate_linear_solve_iters: 2
diff --git a/config/model_configs/prognostic_edmfx_aquaplanet.yml b/config/model_configs/prognostic_edmfx_aquaplanet.yml
index a6f09b10ba9..cdae861c272 100644
--- a/config/model_configs/prognostic_edmfx_aquaplanet.yml
+++ b/config/model_configs/prognostic_edmfx_aquaplanet.yml
@@ -5,6 +5,7 @@
 # rayleigh_sponge: true
 surface_setup: DefaultMoninObukhov
 rad: clearsky
+co2_model: fixed
 turbconv: prognostic_edmfx
 prognostic_tke: true
 edmfx_upwinding: first_order
diff --git a/config/model_configs/prognostic_edmfx_gcmdriven_column.yml b/config/model_configs/prognostic_edmfx_gcmdriven_column.yml
index 046bfe3faf3..322e3510a6a 100644
--- a/config/model_configs/prognostic_edmfx_gcmdriven_column.yml
+++ b/config/model_configs/prognostic_edmfx_gcmdriven_column.yml
@@ -34,6 +34,7 @@ netcdf_output_at_levels: true
 netcdf_interpolation_num_points: [2, 2, 60]
 output_default_diagnostics: false
 rad: allskywithclear
+co2_model: fixed
 insolation: "gcmdriven"
 diagnostics:
   - short_name: [ts, ta, thetaa, ha, pfull, rhoa, ua, va, wa, hur, hus, cl, clw, cli, hussfc, evspsbl, pr]
diff --git a/config/model_configs/rcemipii_box_diagnostic_edmfx.yml b/config/model_configs/rcemipii_box_diagnostic_edmfx.yml
index c8e4fcdfec4..62163d001a6 100644
--- a/config/model_configs/rcemipii_box_diagnostic_edmfx.yml
+++ b/config/model_configs/rcemipii_box_diagnostic_edmfx.yml
@@ -3,6 +3,7 @@ surface_temperature: RCEMIPII
 insolation: rcemipii
 config: box
 rad: allskywithclear
+co2_model: fixed
 turbconv: diagnostic_edmfx
 implicit_diffusion: true
 approximate_linear_solve_iters: 2
diff --git a/config/model_configs/rcemipii_sphere_diagnostic_edmfx.yml b/config/model_configs/rcemipii_sphere_diagnostic_edmfx.yml
index d3d304dbf59..d3501c15ad0 100644
--- a/config/model_configs/rcemipii_sphere_diagnostic_edmfx.yml
+++ b/config/model_configs/rcemipii_sphere_diagnostic_edmfx.yml
@@ -1,6 +1,7 @@
 surface_setup: DefaultMoninObukhov
 surface_temperature: RCEMIPII
 rad: allskywithclear
+co2_model: fixed
 turbconv: diagnostic_edmfx
 implicit_diffusion: true
 approximate_linear_solve_iters: 2
diff --git a/config/perf_configs/flame_perf_target_prognostic_edmfx_aquaplanet.yml b/config/perf_configs/flame_perf_target_prognostic_edmfx_aquaplanet.yml
index a078d4b8798..8821158f118 100644
--- a/config/perf_configs/flame_perf_target_prognostic_edmfx_aquaplanet.yml
+++ b/config/perf_configs/flame_perf_target_prognostic_edmfx_aquaplanet.yml
@@ -7,6 +7,7 @@ dt_save_to_sol: "Inf"
 log_progress: false
 surface_setup: DefaultExchangeCoefficients
 rad: gray
+co2_model: fixed
 vert_diff: false
 turbconv: prognostic_edmfx 
 implicit_diffusion: true
diff --git a/docs/src/tracers.md b/docs/src/tracers.md
index ec737822013..2aef02da42c 100644
--- a/docs/src/tracers.md
+++ b/docs/src/tracers.md
@@ -39,10 +39,21 @@ We interpolate the data from file in time every time radiation is called. The
 interpolation used is the `LinerPeriodFilling` from `ClimaUtilities`. This is a
 linear period-aware interpolation that preserves the annual cycle.
 
+### Prescribed CO2 Profile
+
+In addition to ozone, `ClimaAtmos` can prescribe CO2 concentration using data
+from [Mauna Loa CO2 measurements](https://gml.noaa.gov/ccgg/trends/data.html).
+This option is enabled with `MaunaLoaCO2`. Alternatively, `FixedCO2`
+utilizes a constant value that can be prescribed (by default, 397.547 ppm).
+
 ### More docstrings
 
 ```@docs
 ClimaAtmos.AbstractOzone
 ClimaAtmos.IdealizedOzone
 ClimaAtmos.PrescribedOzone
+
+ClimaAtmos.AbstractCO2
+ClimaAtmos.FixedCO2
+ClimaAtmos.MaunaLoaCO2
 ```
diff --git a/src/cache/cache.jl b/src/cache/cache.jl
index abf60dd48dc..b81badc0088 100644
--- a/src/cache/cache.jl
+++ b/src/cache/cache.jl
@@ -147,7 +147,14 @@ function build_cache(Y, atmos, params, surface_setup, sim_info, aerosol_names)
 
     radiation_args =
         atmos.radiation_mode isa RRTMGPI.AbstractRRTMGPMode ?
-        (start_date, params, atmos.ozone, aerosol_names, atmos.insolation) : ()
+        (
+            start_date,
+            params,
+            atmos.ozone,
+            atmos.co2,
+            aerosol_names,
+            atmos.insolation,
+        ) : ()
 
     hyperdiff = hyperdiffusion_cache(Y, atmos)
     precipitation = precipitation_cache(Y, atmos)
diff --git a/src/cache/tracer_cache.jl b/src/cache/tracer_cache.jl
index 064f3972587..234eaa01efc 100644
--- a/src/cache/tracer_cache.jl
+++ b/src/cache/tracer_cache.jl
@@ -1,4 +1,5 @@
 import Dates: Year
+import ClimaUtilities
 import ClimaUtilities.TimeVaryingInputs
 import ClimaUtilities.TimeVaryingInputs:
     TimeVaryingInput, LinearPeriodFillingInterpolation
@@ -20,6 +21,38 @@ function ozone_cache(::PrescribedOzone, Y, start_date)
     return (; o3, prescribed_o3_timevaryinginput)
 end
 
+co2_cache(_, _, _) = (;)
+function co2_cache(::MaunaLoaCO2, Y, start_date)
+    FT = Spaces.undertype(axes(Y.c))
+    # co2 is well mixed, so it is just a number, but we create an array to
+    # update it with evaluate!
+    co2 = FT[zero(FT)]
+
+    years = []
+    months = []
+    CO2_vals = []
+    open(
+        AA.co2_concentration_file_path(; context = ClimaComms.context(Y.c)),
+        "r",
+    ) do file
+        for line in eachline(file)
+            # Skip comments
+            startswith(line, '#') && continue
+            parts = split(line)
+            push!(years, parse(Int, parts[1]))
+            push!(months, parse(Int, parts[2]))
+            # convert from ppm to fraction, data is in fourth column of the text file
+            push!(CO2_vals, parse(Float64, parts[4]) / 1_000_000)
+        end
+    end
+    # The text file only has month and year, so we set the day to 15th of the month
+    CO2_dates = Dates.DateTime.(years, months, 15)
+    CO2_times =
+        ClimaUtilities.Utils.period_to_seconds_float.(CO2_dates .- start_date)
+    prescribed_co2_timevaryinginput = TimeVaryingInput(CO2_times, CO2_vals)
+    return (; co2, prescribed_co2_timevaryinginput)
+end
+
 function tracer_cache(Y, atmos, prescribed_aerosol_names, start_date)
     if !isempty(prescribed_aerosol_names)
         target_space = axes(Y.c)
@@ -68,5 +101,6 @@ function tracer_cache(Y, atmos, prescribed_aerosol_names, start_date)
         aerosol_cache = (;)
     end
     o3_cache = ozone_cache(atmos.ozone, Y, start_date)
-    return (; aerosol_cache..., o3_cache...)
+    co2_cache_nt = co2_cache(atmos.co2, Y, start_date)
+    return (; aerosol_cache..., o3_cache..., co2_cache_nt...)
 end
diff --git a/src/callbacks/callbacks.jl b/src/callbacks/callbacks.jl
index 1334d397ae3..fd78d427056 100644
--- a/src/callbacks/callbacks.jl
+++ b/src/callbacks/callbacks.jl
@@ -59,6 +59,13 @@ function update_o3!(p, t, ::PrescribedOzone)
     return nothing
 end
 
+update_co2!(_, _, _) = nothing
+function update_co2!(p, t, ::MaunaLoaCO2)
+    evaluate!(p.tracers.co2, p.tracers.prescribed_co2_timevaryinginput, t)
+    return nothing
+end
+
+
 NVTX.@annotate function rrtmgp_model_callback!(integrator)
     Y = integrator.u
     p = integrator.p
@@ -71,6 +78,7 @@ NVTX.@annotate function rrtmgp_model_callback!(integrator)
 
     # If we have prescribed ozone or aerosols, we need to update them
     update_o3!(p, t, p.atmos.ozone)
+    update_co2!(p, t, p.atmos.co2)
     if :prescribed_aerosols_field in propertynames(p.tracers)
         for (key, tv) in pairs(p.tracers.prescribed_aerosol_timevaryinginputs)
             field = getproperty(p.tracers.prescribed_aerosols_field, key)
@@ -255,6 +263,9 @@ NVTX.@annotate function rrtmgp_model_callback!(integrator)
             )
             @. ᶜvmr_o3 = p.tracers.o3
         end
+        if :co2 in propertynames(p.tracers)
+            @. rrtmgp_model.volume_mixing_ratio_co2 = p.tracers.co2
+        end
     end
 
     set_surface_albedo!(Y, p, t, p.atmos.surface_albedo)
diff --git a/src/parameterized_tendencies/radiation/radiation.jl b/src/parameterized_tendencies/radiation/radiation.jl
index 9c6c70a18b0..30ac6ef7304 100644
--- a/src/parameterized_tendencies/radiation/radiation.jl
+++ b/src/parameterized_tendencies/radiation/radiation.jl
@@ -86,12 +86,24 @@ function idealized_ozone(z::FT) where {FT}
     return g1 * p^g2 * exp(-p / g3) * PPMV_TO_VMR
 end
 
+#######
+# CO2 #
+#######
+
+function center_vmr_co2(co2::FixedCO2)
+    return co2.value
+end
+
+# Initialized in callback
+center_vmr_co2(::MaunaLoaCO2) = NaN
+
 function radiation_model_cache(
     Y,
     radiation_mode::RRTMGPI.AbstractRRTMGPMode,
     start_date,
     params,
     ozone,
+    co2,
     aerosol_names,
     insolation_mode;
     interpolation = RRTMGPI.BestFit(),
@@ -150,6 +162,10 @@ function radiation_model_cache(
         else
             center_volume_mixing_ratio_o3 = center_vmr_o3(ozone, Y)
 
+            # FT is needed in case FixedCO2 is being used with an inconsistent
+            # floating point type
+            center_volume_mixing_ratio_co2 = FT(center_vmr_co2(co2))
+
             # the first value for each global mean volume mixing ratio is the
             # present-day value
             input_vmr(name) =
@@ -160,7 +176,7 @@ function radiation_model_cache(
                 center_volume_mixing_ratio_h2o = NaN, # initialize in tendency
                 center_relative_humidity = NaN, # initialized in callback
                 center_volume_mixing_ratio_o3,
-                volume_mixing_ratio_co2 = input_vmr("carbon_dioxide_GM"),
+                volume_mixing_ratio_co2 = center_volume_mixing_ratio_co2,
                 volume_mixing_ratio_n2o = input_vmr("nitrous_oxide_GM"),
                 volume_mixing_ratio_co = input_vmr("carbon_monoxide_GM"),
                 volume_mixing_ratio_ch4 = input_vmr("methane_GM"),
diff --git a/src/solver/model_getters.jl b/src/solver/model_getters.jl
index 53c15833b99..bbd1fc9d741 100644
--- a/src/solver/model_getters.jl
+++ b/src/solver/model_getters.jl
@@ -308,6 +308,18 @@ function get_ozone(parsed_args)
     return parsed_args["prescribe_ozone"] ? PrescribedOzone() : IdealizedOzone()
 end
 
+function get_co2(parsed_args)
+    if isnothing(parsed_args["co2_model"])
+        return nothing
+    elseif lowercase(parsed_args["co2_model"]) == "fixed"
+        return FixedCO2()
+    elseif lowercase(parsed_args["co2_model"]) == "maunaloa"
+        return MaunaLoaCO2()
+    else
+        error("The CO2 models supported are $(subtypes(AbstractCO2))")
+    end
+end
+
 function get_cloud_in_radiation(parsed_args)
     isnothing(parsed_args["prescribe_clouds_in_radiation"]) && return nothing
     return parsed_args["prescribe_clouds_in_radiation"] ?
diff --git a/src/solver/type_getters.jl b/src/solver/type_getters.jl
index 082508c161b..675738a696d 100644
--- a/src/solver/type_getters.jl
+++ b/src/solver/type_getters.jl
@@ -30,6 +30,16 @@ function get_atmos(config::AtmosConfig, params)
         @warn "prescribe_ozone is set to nothing with an RRTMGP model. Resetting to IdealizedOzone. This behavior will stop being supported in some future release"
         ozone = IdealizedOzone()
     end
+    co2 = get_co2(parsed_args)
+    with_rrtgmp = radiation_mode isa RRTMGPI.AbstractRRTMGPMode
+    if with_rrtgmp && isnothing(co2)
+        @warn (
+            "co2_model set to nothing with an RRTGMP model. Resetting to FixedCO2"
+        )
+        co2 = FixedCO2()
+    end
+    (isnothing(co2) && !with_rrtgmp) &&
+        @warn ("$(co2) does nothing if RRTGMP is not used")
 
     diffuse_momentum = !(forcing_type isa HeldSuarezForcing)
 
@@ -57,6 +67,7 @@ function get_atmos(config::AtmosConfig, params)
     atmos = AtmosModel(;
         moisture_model,
         ozone,
+        co2,
         radiation_mode,
         subsidence = get_subsidence_model(parsed_args, radiation_mode, FT),
         ls_adv = get_large_scale_advection_model(parsed_args, FT),
diff --git a/src/solver/types.jl b/src/solver/types.jl
index 6059303dc09..ebdbe804ca6 100644
--- a/src/solver/types.jl
+++ b/src/solver/types.jl
@@ -127,6 +127,42 @@ Refer to ClimaArtifacts for more information on how to obtain the artifact.
 """
 struct PrescribedOzone <: AbstractOzone end
 
+"""
+    AbstractCO2
+
+Describe how CO2 concentration should be set.
+"""
+abstract type AbstractCO2 end
+
+"""
+    FixedCO2
+
+Implement a static CO2 profile as read from disk.
+
+The data used is the one distributed with `RRTGMP.jl`.
+
+By default, this is 397.547 parts per million.
+
+This is the volume mixing ratio.
+"""
+struct FixedCO2{FT} <: AbstractCO2
+    value::FT
+
+    function FixedCO2(; FT = Float64, value = FT(397.547e-6))
+        return new{FT}(value)
+    end
+end
+
+"""
+    MuanaLoaCO2
+
+Implement a time-varying CO2 profile as read from disk.
+
+The data from the Mauna Loa CO2 measurements is used. It is a assumed that the
+concentration is constant.
+"""
+struct MaunaLoaCO2 <: AbstractCO2 end
+
 """
     AbstractCloudInRadiation
 
@@ -456,6 +492,7 @@ Base.@kwdef struct AtmosModel{
     F,
     S,
     OZ,
+    CO2,
     RM,
     LA,
     EXTFORCING,
@@ -486,8 +523,12 @@ Base.@kwdef struct AtmosModel{
     forcing_type::F = nothing
     subsidence::S = nothing
 
+    # Currently only relevant for RRTGMP, but will hopefully become standalone
+    # in the future
     """What to do with ozone for radiation (when using RRTGMP)"""
     ozone::OZ = nothing
+    """What to do with co2 for radiation (when using RRTGMP)"""
+    co2::CO2 = nothing
 
     radiation_mode::RM = nothing
     ls_adv::LA = nothing
diff --git a/src/utils/AtmosArtifacts.jl b/src/utils/AtmosArtifacts.jl
index 2a3092406c4..9ae2e90ce85 100644
--- a/src/utils/AtmosArtifacts.jl
+++ b/src/utils/AtmosArtifacts.jl
@@ -72,7 +72,7 @@ end
 
 Construct the file path for the 60arcsecond orography data NetCDF file.
 
-Downloads the 60arc-second dataset by default. 
+Downloads the 60arc-second dataset by default.
 """
 function earth_orography_file_path(; context = nothing)
     filename = "ETOPO_2022_v1_60s_N90W180_surface.nc"
@@ -82,4 +82,13 @@ function earth_orography_file_path(; context = nothing)
     )
 end
 
+"""
+    co2_concentration_file_path(; context = nothing)
+
+Construct the file path for the co2 concentration CSV file.
+"""
+function co2_concentration_file_path(; context = nothing)
+    return joinpath(@clima_artifact("co2_dataset", context), "co2_mm_mlo.txt")
+end
+
 end
diff --git a/test/coupler_compatibility.jl b/test/coupler_compatibility.jl
index 82a70fb466b..38abd299e59 100644
--- a/test/coupler_compatibility.jl
+++ b/test/coupler_compatibility.jl
@@ -213,6 +213,7 @@ end
             "surface_setup" => "PrescribedSurface",
             "moist" => "equil",
             "rad" => "clearsky",
+            "co2_model" => "fixed",
             "turbconv" => "diagnostic_edmfx",
             # NOTE: We do not output diagnostics because it leads to problems with Ubuntu on
             # GitHub actions taking too long to run (for unknown reasons). If you need this,
diff --git a/test/restart.jl b/test/restart.jl
index 92165e40875..04b500a80f3 100644
--- a/test/restart.jl
+++ b/test/restart.jl
@@ -406,6 +406,7 @@ if MANYTESTS
                             "rayleigh_sponge" => true,
                             "insolation" => "timevarying",
                             "rad" => radiation,
+                            "co2_model" => "fixed",
                             "dt_rad" => "1secs",
                             "surface_setup" => "DefaultMoninObukhov",
                             "call_cloud_diagnostics_per_stage" => true,  # Needed to ensure that cloud variables are computed