remindmodel · tabeado · Jul 16, 2026 · Jul 21, 2026 · Jul 22, 2026 · Jul 22, 2026
diff --git a/core/datainput.gms b/core/datainput.gms
@@ -290,9 +290,9 @@ fm_dataglob("inco0", "oae_ng") = fm_dataglob("inco0", "oae_ng") / (cm_33_OAE_eff
 fm_dataglob("inco0", "oae_el") = fm_dataglob("inco0", "oae_el") / (cm_33_OAE_eff / sm_c_2_co2);
 
 *** convert inco0, floorcost and omv to REMIND units by applying a factor 0.001
-***   category          energy technology   ccs technology    process-based industry 
-***   input data unit   $/kW                $/(tC/a)          $/(t/a)
-***   REMIND unit       T$/TW               T$/(GtC/a)        T$/(Gt/a)
+***   category          energy technology   ccs technology    process-based industry            weathering
+***   input data unit   $/kW                $/(tC/a)          $/(t/a)                         $/(t rocks/a)
+***   REMIND unit       T$/TW               T$/(GtC/a)        T$/(Gt/a)                       T$/(Gt rocks/a)
 fm_dataglob("inco0",te)        = s_DpKW_2_TDpTW   * fm_dataglob("inco0",te);
 fm_dataglob("floorcost",te)    = s_DpKW_2_TDpTW   * fm_dataglob("floorcost",te);
 fm_dataglob("omv",te)          = s_DpKWa_2_TDpTWa * fm_dataglob("omv",te);

diff --git a/core/input/generisdata_tech.prn b/core/input/generisdata_tech.prn
@@ -1,7 +1,7 @@
 *** SOF ./core/input/generisdata_tech.prn
 $ontext
 tech_stat   technology status: how close a technology is to market readiness. Scale: 0-3, with 0 'I can go out and build a GW plant today' to 3 'Still some research necessary'
-inco0       Initial investment costs given in $[2015] / kW[output] capacity; for dac/prc cc: $[2015] / (tC[captured]/a); for other indutry prc: $[2015]/(t[output]/a)
+inco0       Initial investment costs given in $[2015] / kW[output] capacity; for dac/prc cc: $[2015] / (tC[captured]/a); for other indutry prc: $[2015]/(t[output]/a); for weathering:  $[2015]/(t rock/a)
 floorcost   Floor investment costs, given in $[2015] / kW[output]; for dac: $[2015] / (tC[captured]/a)
 constrTme   Construction time in years, needed to calculate turn-key cost premium compared to overnight costs
 lifetime    Average lifetime of a technology, given in years. Effective maximum lifetime is longer than that.
@@ -155,14 +155,14 @@ lifetime               30        30          45          45          45
 
 *** carbon management
 +           ccsinjeon   ccsinjeoff    weathering         dac      oae_ng      oae_el
-tech_stat           0            0                         4
-inco0             350          525          0.01       18800         200         400
+tech_stat           0            0             1           4 
+inco0             350          525            43        18800        200         400
 floorcost                                               4800
 constrTme           3            5
 lifetime           40           40            20          20          25          25
 mix0             1.00         1.00
 eta              1.00         1.00          1.00        1.00        1.00        1.00
-omf              0.06         0.12          0.84       0.025        0.35        0.17
+omf              0.06         0.12          0.59       0.025        0.35        0.17
 ccap0                                                 0.0008
 learn                                                   0.15
 
@@ -303,6 +303,13 @@ Ocean Liming - oae
     Costs per tC removed is calculated in the code as it depends on the efficiency (tCO2/tCaO; exogenous):
         cost (USD/tC) = inco0 (USD/tCaO) / ( efficiency (tCO2/tCaO) / 3.66 (tCO2/tC) )
 
+Enhanced Rock Weathering - weathering
+    Parameterization based on Strefler et al (2018) doi.org/10.1088/1748-9326/aaa9c4
+    annuity factor = 0.08 for lifetime of 20 years and r = 0.05; capacity factor = 0.69
+    inco0: 5 (USD/t rock) * 0.69 / 0.08 = 43 USD/t rock/a for mining and production
+    omf: O&M cost from rock mining & production (25 USD/t rock) and transportation & distribution (12 USD/t rock), i.e. 37/(43/0.69) = 0.86
+    To use the upper Capital Cost estimate from Strefler et al, 15 USD/t rock, set inco0 = 129 and omf = 0.2
+
 Gas to Liquids (GtL) Fischer-Tropsch Process - gasftrec/gasftcrec
     efficiency eta = 0.60 (0.57 with capture), estimation at higher end of efficiency spectrum
     Details in Issue 518/PR 2034

diff --git a/main.gms b/main.gms
@@ -1086,10 +1086,17 @@ parameter
 ;
   cm_gs_ew                 = 20;     !! def = 20  !! regexp = is.numeric
 *'
+
 parameter
-  cm_LimRock                "limit amount of rock spread each year [Gt]"
+  cm_33_EW_rockRemPot             "Maximum CO2 removal potential per ton of rock."
 ;
-  cm_LimRock               = 1000;   !! def = 1000
+  cm_33_EW_rockRemPot            = 0.3;   !! def = 0.3 t CO2 / t basalt
+*' Theoretical potential is influenced by the chemical composition of the rock, in particular calcium and magnesium content. 
+*' * (0.3): 0.3 t CO2 / t basalt is the commonly used average, see e.g. Strefler et al 2018 (SI-A Table A-1)
+*' * (0.2-0.4): 0.2 and 0.4 t CO2 / t basalt are a lower and upper bound in Strefler et al 2018 (SI-A Table A-1) 
+*' The theoretical potential may not be reached due to different loss pathways (dissolution through strong acids;
+*' secondary mineral formation (esp. clays); secondary carbonate formation (where carbon retention is only temporary)) which 
+*' strongly depend on the local soil conditions. Reduction below 50% of the theoretical potential is well possible. 
 *'
 parameter
   cm_33_EW_upScalingRateLimit    "Annual growth rate limit on upscaling of mining & spreading rocks on fields"

diff --git a/modules/33_carbonRemoval/portfolio/datainput.gms b/modules/33_carbonRemoval/portfolio/datainput.gms
@@ -39,7 +39,9 @@ s33_step = 2.5;
 *' @code
 *' fix costs [T$/Gt stone]. Data from strefler et al. in $/t stone: mining, crushing, grinding (5.0 investment costs, 25.1 O&M costs), spreading (12.1 O&M costs)
 s33_costs_fix = 0.0422;
-s33_co2_rem_pot = 0.3 * 12/44;       !! default for basalt, for Olivine 1.1
+s33_rockRemPot = cm_33_EW_rockRemPot * 12/44;       !! default for basalt is 0.3 t CO2/t rock, for Olivine 1.1 t CO2/t rock. Converted to t C/t rock.
+*' Sources for loss pathways that would reduce the total removal potential per ton rock: 
+*' https://www.carbon-drawdown.de/blog/2026-7-18-where-does-the-co-removal-potential-of-enhanced-weathering-actually-go; https://cdrxiv.org/preprint/417
 
 *' rock weathering rate (i.e. fraction of rock weathering per year) at ambient temperature (25 degree C), based on 
 *' eq 2 in strefler, amann et al. (2018): 
@@ -54,17 +56,14 @@ p33_rock_weath_rate("2") = s33_rock_weath_rate_ambientT * 0.29;
 p33_fedem("weathering", "feels") = 6.62 * cm_gs_ew**(-1.16);
 p33_fedem("weathering", "fedie") = 0.3;
 
-*' Factor distributing the global rock limit across regions according to population
-p33_LimRock(regi) = pm_pop("2005",regi) / sum(regi2,pm_pop("2005",regi2));
-
 *' Annual growth rate limit on upscaling of mining & spreading rocks on fields
 p33_EW_upScalingLimit(ttot) = cm_33_EW_upScalingRateLimit;
 
 *' Calculation of short term limit on rocks spread on field in terms of Gt rocks that can be spread. 
 p33_EW_shortTermEW_Limit(regi) = cm_33_EW_shortTermLimit * sum(rlf, f33_maxProdGradeRegiWeathering(regi, rlf));
 
 *' Narrative switch: what share of cropland can be used for EW?
-parameter f33_EW_maxShareOfCropland(ext_regi) "Maximum share of cropland available for enhanced weathering by region" / %cm_33_EW_maxShareOfCropland% /;
+parameter f33_EW_maxShareOfCropland(ext_regi) "Maximum share of suitable cropland available for enhanced weathering by region" / %cm_33_EW_maxShareOfCropland% /;
 p33_EW_maxShareOfCropland(regi) = 1; !! if no value is assigned to GLO, the default share is set to 100%
 p33_EW_maxShareOfCropland(regi) = f33_EW_maxShareOfCropland("GLO"); !! if a value is assigned to GLO, this value is set for all regions
 loop(ext_regi$f33_EW_maxShareOfCropland(ext_regi),

diff --git a/modules/33_carbonRemoval/portfolio/declarations.gms b/modules/33_carbonRemoval/portfolio/declarations.gms
@@ -9,7 +9,7 @@ scalars
 *** Multiple options
 sm_capture_rate_cdrmodule       "CO2 capture rate for CDR energy and process emissions, i.e. fegas use in OAE and DAC and for calcination emissions in oae" / 0.9 /
 *** EW
-s33_co2_rem_pot                 "specific carbon removal potential [Gt C per Gt ground rock]"
+s33_rockRemPot                 "specific carbon removal potential [Gt C per Gt ground rock]"
 s33_rock_weath_rate_ambientT    "fraction of stone weathering per year at ambient temperature (25 degree C)"
 s33_costs_fix                   "fixed costs for mining, grinding, spreading [T$/Gt stone]"
 s33_step                        "size of bins in v33_weathering_onfield [Gt stone]"
@@ -24,7 +24,6 @@ parameters
 *** Multiple options
 p33_fedem(all_te,all_enty)               "final energy demand of each technology [EJ/GtC] (for EW the unit is [EJ/Gt stone])"
 *** EW
-p33_LimRock(all_regi)                    "regional share of EW limit [fraction], calculated ex ante for a maximal annual amount of 8 Gt rock in D:\projects\CEMICS\paper_technical\supply_curve_transport_remind_regions.m"
 p33_rock_weath_rate(rlf)                 "fraction of stone weathering per year depending on climate grade (warm or temperate)"
 p33_EW_upScalingLimit(ttot)              "Annual growth rate limit on upscaling of mining & spreading rocks on fields"
 p33_EW_shortTermEW_Limit(all_regi)       "Limit on 2030 potential for enhanced weathering, defined in Gt rocks, based on % of land on which EW is applied"
@@ -89,7 +88,6 @@ q33_EW_omcosts(ttot,all_regi)  "calculates O&M costs for spreading ground rocks
 q33_EW_FEdemand(ttot,all_regi,all_enty)  "calculates final energy demand from enhanced weathering"
 q33_EW_potential(ttot,all_regi,rlf)  "limits the total potential of EW per region and grade"
 q33_EW_emi(ttot,all_regi)  "calculates amount of carbon captured by EW"
-q33_EW_LimEmi(ttot,all_regi)  "limits EW to a maximal annual amount of ground rock of cm_LimRock"
 q33_EW_upscaling_rate(ttot, all_regi) "limits spreading of rock to a steep but credible upscaling rate"
 q33_EW_ShortTermBound(ttot,all_regi)   "Limits short term potential for enhanced weathering"
 

diff --git a/modules/33_carbonRemoval/portfolio/equations.gms b/modules/33_carbonRemoval/portfolio/equations.gms
@@ -154,7 +154,7 @@ q33_EW_emi(t,regi)..
     vm_emiCdrTeDetail(t,regi, "weathering")
     =e=
     sum((rlf_cz33, rlf),
-        - v33_EW_onfield_tot(t,regi,rlf_cz33,rlf) * s33_co2_rem_pot * p33_rock_weath_rate(rlf_cz33)
+        - v33_EW_onfield_tot(t,regi,rlf_cz33,rlf) * s33_rockRemPot * p33_rock_weath_rate(rlf_cz33)
         )
     ;
 
@@ -189,16 +189,6 @@ q33_EW_potential(t,regi,rlf_cz33)..
     ;
 
 
-***---------------------------------------------------------------------------
-*'  An annual limit for the maximum global amount of rocks spread [Gt] can be set via cm_LimRock,
-*'  e.g. due to sustainability concerns.
-***---------------------------------------------------------------------------
-q33_EW_LimEmi(t,regi)..
-    sum((rlf_cz33, rlf), v33_EW_onfield(t,regi,rlf_cz33,rlf))
-    =l=
-    cm_LimRock * p33_LimRock(regi)
-    ;
-
 ***---------------------------------------------------------------------------
 *' Short term bound on spreading of rock
 ***---------------------------------------------------------------------------

diff --git a/modules/33_carbonRemoval/portfolio/realization.gms b/modules/33_carbonRemoval/portfolio/realization.gms
@@ -19,8 +19,7 @@
 *' on crop fields where it weathers in reaction with water and atmospheric CO2. Electricity is needed to grind the
 *' rocks and diesel is needed for transportation and spreading on crop fields. The weathering process leads to an exponential
 *' decay over time of the spread rocks. There is an upper limit on the amount of rock that can be on the fields, so that
-*' in equilibrium only the part that decays in one timestep can be replaced in the next. In addition, an arbitrary
-*' limit of the amount of rock spread each year can be set in cm_LimRock. Costs consist of costs for capital, O&M,
+*' in equilibrium only the part that decays in one timestep can be replaced in the next. Costs consist of costs for capital, O&M,
 *' distribution and transport (grades depend on region specific transport distance from mine to fields).
 *'
 *' (OAE) Ocean alkalinity enhancement via ocean liming draws down CO2 from the atmosphere by adding (hydrated) lime

diff --git a/standalone/MOFEX/MOFEX.gms b/standalone/MOFEX/MOFEX.gms
@@ -170,7 +170,6 @@ c_export_tax_scen    "choose which oil export tax is used in the model. 0 = none
 cm_iterative_target_adj "whether or not a tax or a budget target should be iteratively adjusted depending on actual emission or forcing level"
 cm_gdximport_target   "whether or not the starting value for iteratively adjusted budgets, tax scenarios, or forcing targets (emiscen 5,6,8,9) should be read in from the input.gdx"
 cm_gs_ew              "grain size (for enhanced weathering, CDR module) [micrometre]"
-cm_LimRock             "limit amount of rock spread each year [Gt]"
 cm_expoLinear_yearStart "time at which carbon price increases linearly instead of exponentially"
 
 c_budgetCO2FFI        "carbon budget for CO2 emissions from FFI (in GtCO2)"
@@ -299,7 +298,6 @@ cm_iterative_target_adj  = 0;      !! def = 0
 cm_gdximport_target      = 0;      !! def = 0
 $setglobal c_SSP_forcing_adjust  forcing_SSP2   !! def = forcing_SSP2
 cm_gs_ew                 = 20;     !! def = 20
-cm_LimRock               = 1000;   !! def = 1000
 cm_expoLinear_yearStart  = 2050;   !! def = 2050
 c_budgetCO2FFI           = 1000;   !! def = 1000
 c_abtrdy                 = 2010;   !! def = 2010

diff --git a/standalone/template.gms b/standalone/template.gms
@@ -166,7 +166,6 @@ c_export_tax_scen    "choose which oil export tax is used in the model. 0 = none
 cm_iterative_target_adj "whether or not a tax or a budget target should be iteratively adjusted depending on actual emission or forcing level"
 cm_gdximport_target   "whether or not the starting value for iteratively adjusted budgets, tax scenarios, or forcing targets (emiscen 5,6,8,9) should be read in from the input.gdx"
 cm_gs_ew              "grain size (for enhanced weathering, CDR module) [micrometre]"
-cm_LimRock             "limit amount of rock spread each year [Gt]"
 cm_expoLinear_yearStart "time at which carbon price increases linearly instead of exponentially"
 
 c_budgetCO2FFI        "carbon budget for CO2 emissions from FFI (in GtCO2)"
@@ -253,7 +252,6 @@ cm_iterative_target_adj  = 0;      !! def = 0
 cm_gdximport_target      = 0;      !! def = 0
 $setglobal c_SSP_forcing_adjust  forcing_SSP2   !! def = forcing_SSP2
 cm_gs_ew                 = 20;     !! def = 20
-cm_LimRock               = 1000;   !! def = 1000
 cm_expoLinear_yearStart  = 2050;   !! def = 2050
 c_budgetCO2FFI           = 1000;   !! def = 1000
 c_abtrdy                 = 2010;   !! def = 2010

diff --git a/standalone/trade/trade.gms b/standalone/trade/trade.gms
@@ -174,7 +174,6 @@ c_export_tax_scen    "choose which oil export tax is used in the model. 0 = none
 cm_iterative_target_adj "whether or not a tax or a budget target should be iteratively adjusted depending on actual emission or forcing level"
 cm_gdximport_target   "whether or not the starting value for iteratively adjusted budgets, tax scenarios, or forcing targets (emiscen 5,6,8,9) should be read in from the input.gdx"
 cm_gs_ew              "grain size (for enhanced weathering, CDR module) [micrometre]"
-cm_LimRock             "limit amount of rock spread each year [Gt]"
 cm_expoLinear_yearStart "time at which carbon price increases linearly instead of exponentially"
 
 c_budgetCO2FFI        "carbon budget for CO2 emissions from FFI (in GtCO2)"
@@ -304,7 +303,6 @@ cm_iterative_target_adj  = 0;      !! def = 0
 cm_gdximport_target      = 0;      !! def = 0
 $setglobal c_SSP_forcing_adjust  forcing_SSP2   !! def = forcing_SSP2
 cm_gs_ew                 = 20;     !! def = 20
-cm_LimRock               = 1000;   !! def = 1000
 cm_expoLinear_yearStart  = 2050;   !! def = 2050
 c_budgetCO2FFI           = 1000;   !! def = 1000
 c_abtrdy                 = 2010;   !! def = 2010