The physical processes causing global sea-level rise are highlighted in the animation. The main causes are thermal expansion of oceans, as they accumulate the excess heat caused by greenhouse gas emissions, the melting of ice from the ice sheets and glaciers, as well as changes in land water storage such as lakes. Regionally, sea level changes vary quite dramatically. The reasons for this are different to the global causes of sea-level changes and include changes to sea water density, influenced by salinity and temperature.