This study analyses the possible approaches to greenhouse gas abatement by industrialised (Annex I) countries, to calculate their comparability. The reduction targets for Annex I countries and the abatement costs of achieving these different aggregated reduction targets show a wide range. To meet the EU climate target of 2°C, a 30% emission reduction by the EU is needed, combined with comparable reduction efforts by other Annex I countries and a 15 to 30% below-baseline emission reduction by developing countries.