The Arctic sea-ice cover underwent remarkable changes in the past decade. The impact on, and relation to, global climate change of these developments is subject to a wide range of ongoing research often based on numerical models. However, the description of sea-ice processes in for instance global climate models is often not consistent with the current knowledge of the nature of sea ice. Neglected or only partially implemented processes may lead to different feedbacks between sea ice and other climate components and thus yield diverging model results. Here, we take a closer look at the impact of including sea-ice ridging in a global climate model. Ridging occurs under convergent or shear sea-ice motion, when floes break-up into smaller blocks which then often pile up along the edge of the thicker floe. This process turns thin level ice into thicker deformed ice and, as ice mass is conserved, results in the opening of leads. During winter the ocean loses more heat to the atmosphere through leads than through the insulating ice cover, which in turn enhances sea-ice growth. In summer the ocean may absorb more solar radiation through leads leading to warmer water temperatures, which then increase melting of the adjacent ice. In order to investigate these contradictory implications of ridging we applied the ridging scheme of Lipscomb and others (2007, JGR) to a coupled atmosphere–sea-ice–ocean climate model. We chose a direct derivative of the Geophysical Fluid Dynamics Laboratory's IPCC AR4 model CM2.1. The scheme redistributes ice between ten ice-thickness categories depending on the state of ice motion. We carried out six experiments covering the effect of single vs multi ice-thickness categories and ridging under two different sets of ice and snow albedo. We found that the ridging process increases the overall sea-ice volume significantly though the effect is smaller than that of a generally higher albedo. It also results in a more dynamically influenced spatial distribution of the ice mass. The two different sets of albedo show that a thicker ice cover yields generally cooler surface temperatures in the Arctic. However, the increased open-water area in the ridging experiments results in slightly warmer atmosphere and ocean temperatures as well as a lower surface albedo in summer compared with the experiments without ridging.