A policymaker argues: "The difference between the 2°C and 1.5°C Paris targets is trivial — we should focus resources on 2°C compliance rather than the politically unrealistic 1.5°C goal." Construct a rigorous scientific and economic rebuttal incorporating IPCC SR1.5 (non-linear impacts), tipping points, the MDC/MCC framework, and intergenerational equity. Honestly engage the "politically unrealistic" point.