Border carbon adjustments aim at reducing the negative competitiveness effects and emission leakage resulting from unilateral climate policy. The analyses by Matthias Weitzel and Sonja Peterson show that this instrument has only limited effects on competitiveness and leakage. It can further be misused for other purposes e.g. for trade policy and is neither politically nor administratively feasible. Border carbon adjustments are thus not be considered as an instrument of choice in international climate policy.