The relationship between greenhouse-gas forcing, global mean temperature change and sea-level rise due to thermal expansion of the oceans is investigated using upwelling-diffusion and pure diffusion models. The sensitivities of sea-level to short-timescale forcing and deep-water formation rate changes are examined. The greenhouse-gas-induced thermal expansion contribution to sea-level rise between 1880 and 1985 is estimated at 2-5 cm. Projections are made to the year 2025 for different forcing scenarios. For the period 1985-2025 the estimate of greenhouse-gas-induced warming is 0.6-1.0 °C. The concomitant oceanic thermal expansion would raise sea level by 4-8 cm.