The climate change agreements (CCAs) in the UK were negotiated with a number of energy-intensive industrial sectors, and offered a reduction in the rate of the climate change levy (CCL), provided that negotiated energy efficiency targets were met. Through modelling and by analysis of the results of the first target period, this paper analyses the stringency of the targets, and the economic and environmental implications of the CCAs. It concludes that, while the targets in themselves were not stringent, and were in the main met well before the due date, the CCAs appear to have had an 'awareness effect' in stimulating energy savings. This has resulted in overall environmental benefits above those which would have derived from the imposition of a flat-rate tax with no rebate and no CCAs, and economic benefits for the sectors and companies with which CCAs were negotiated. (c) 2005 Elsevier Ltd. All rights reserved.