This paper investigates climate control coalition games. It studies whether incentives exist for non-cooperating, nations like the USA to join a coalition based upon issue linkage. Issue linkage is considered through increased R&D expenditures triggering improved technological innovations that advance energy efficiencies. Model calculations demonstrate that incentive.,,, exist for non-cooperating countries like the USA to join a climate control coalition if nations cooperate on technological innovations. Restrictions on trade Such as sanction mechanisms against non-cooperating Countries are not necessarily an incentive to join a coalition. Technological spillover effects lead to improved economic Situations and increased energy efficiencies in non-cooperating countries. (C) 2003 Elsevier Ltd. All rights reserved.