Unilateral or sub-global policies to combat climate change are potentially sensitive to free-riding and carbon leakage. One way of dealing with carbon leakage and competitiveness is the imposition of border adjustment measures for competing imports, for example in the form of the obligation to importers of goods to purchase and surrender emissions allowances to the authorities when importing. In this paper, we explore some implications of border adjustment measures in the EU ETS, for sectors that might be subject to carbon leakage. We examine the implications of two variants of these measures on the competitiveness of these sectors and on the global environment with the help of a multi-sector, multi-region computable general equilibrium (CGE) model of the global economy. Our calculations suggest that border adjustment might reduce the sectoral rate of leakage of the iron and steel industry rather forcefully, but that the reduction would be less for the mineral products sector, including cement. The reduction of the overall or macro rate of leakage would be modest. So, from an environmental point of view border tax adjustments would not be a very effective policy measure, but might mainly be justified by considerations of sectoral competitiveness. © 2009 Elsevier Ltd. All rights reserved.