Abstract This study critically examines the use of ‘no additional warming’ approaches, such as temperature neutrality (TN), to determine national climate policy on agricultural methane (CH 4 ). The reduced-complexity climate model MAGICC was used to quantify future national warming contributions for Ireland (a country with high per-capita CH 4 emissions driven by large-scale dairy and beef production) under a business-as-usual pathway and three alternative scenarios: (1) TN, (2) a split-gas emission target, or (3) net-zero greenhouse gas emissions by 2050. TN implicitly ‘grandfathers’ CH 4 emissions, ‘rewarding’ modest emission reductions even when per capita warming remains high, thereby shifting the mitigation burden and constraining the developmental space for low-income, food-insecure countries. Weaker CH 4 emission reduction ambition, i.e. use of TN at the national level, is often justified on the basis of protecting global food security, because it can avoid ‘emission leakage’ from countries that export livestock products with below-average GHG intensities. However, this study demonstrates such justifications have little merit given that global trade in animal-sourced foods largely benefits wealthy markets, and often relies on imported feed, contributing to indirect land use change. The study concludes that the TN approach is not a robust basis for fair and effective national climate policy, and risks a potentially costly underestimation of both long-term CH 4 mitigation and carbon dioxide removal in the context of national planning for an equitable, sustainable, food secure future.
Duffy et al. (Tue,) studied this question.