Scenario: N_only_no_tripartite¶

Policy question¶

What is the minimum cost of meeting VP3 nitrogen targets with no political constraints on measure mix? This is the pure N cost-effectiveness frontier — the theoretical optimum if Denmark could choose any mix of measures purely based on DKK per ton N reaching the coast.

Parameters¶

var_N = 1
var_P = 0
var_B = 0
var_C = 0
// Tripartite constraints: ALL INACTIVE

Key results¶

Indicator	Value
Total cost (mDKK/yr)
N reduction achieved (tons N/yr)
Cost per ton N at coast (DKK/ton N)
Dominant measures selected
Geographic distribution of selected measures

Why this scenario matters¶

This is the benchmark for every other scenario. Any additional cost above this represents: - The cost of also meeting P targets - The cost of political constraints (tripartite floors) - The cost of biodiversity or climate co-benefits (when those modules are active)

The cost-effectiveness frontier generated here (if run at multiple target levels) shows the marginal cost curve for N reduction in Denmark — a fundamental policy input.

Expected measure mix¶

Based on model structure and parameter ranges: - CCS likely dominant on sandy-soil, high-livestock fields in low-retention catchments (cheap, good N effect, low opportunity cost) - N10 likely selected on intensively fertilized fields (very cheap) - WL likely selected in high-retention catchments (no retention penalty — NR advantage) - BZ10/20 likely selected near the coast where leaching is high and retention is low - SA, LRh only in the ~97 / 13 catchments where they have differentiated effects

Baseline_NP — the full-constraint run → Baseline_NP minus N_only_no_tripartite = total "policy overhead"
No_tripartite — adds P targets