Relative sea level in Venice rose by about 2.5 mm/year in the past 150 years due to the combined effect of subsidence and mean sea-level rise. We estimate the likely range of mean sea-level rise in Venice by 2100 due to climate changes to be between about 10 and 110 cm, with an improbable yet possible high-end scenario of about 170 cm. Projections of subsidence are not available, but historical evidence demonstrates that they can increase the hazard posed by climatically induced sea-level rise.

In South Korea, over 27 % of the population of 75 million live in coastal city areas. Despite the potential threat of sea level rise, there is little knowledge of how sea level has varied in the past and how those variations compare to present day sea level rise. In this study, new methods are proposed to improve the understanding of past sea level around the Korean Peninsula. The degree to which this understanding can inform policy makers about future sea level rise is also explored.

Sea ice reduction is accelerating in the Barents-Kara Seas, and the air temperature in this region is increasing much more rapidly than the global average temperature. In this study, we examined how the rapid air temperature increase, so-called Arctic amplification, is associated with the sea ice reduction in the Barents-Kara Seas in terms of a positive feedback process between the ocean surface and the atmosphere over the sea ice reduced areas. Details of this feedback are presented/discussed.

Analysis reveals that “Arctic amplification”, lower tropospheric winter temperature rise in the Arctic, is due to sea ice melting and the resulting increase in the amount of turbulent heat flux from the ocean. As a result of increased turbulent heat flux, lower atmosphere warms up, resulting in increased downward longwave radiation. A detailed physical mechanism is presented together with an explanation why this positive feedback process is currently possible in the Barents–Kara seas.