The main factors that can cause an average rise in sea level are the thermal expansion of the oceans, the melting of ice caps and the change in salinity due to the exchange of water masses between the oceans and the freshwater reserves of the territory.
These contributions are commonly attributed to global climate change largely induced by anthropogenic emissions of greenhouse gases with consequent global warming. Furthermore, the absolute sea level also indirectly depends on the deformation of the solid earth caused by variations in the gravitational field and in the volume of the global ocean basin.
An important contribution to the global sea level variation is also given by the progressive melting of mountain glaciers and small ice caps, particularly sensitive to the global warming that has been affecting our planet in recent decades.
For the period 1993-2010, the contribution of glaciers and polar ice caps to sea level rise was estimated to be in the order of 30%.
Understanding of climate change-related sea-level rise
The study: Public understanding of climate change-related sea-level rise, published on the PloS one, explained: "Sea-level rise resulting from climate change is impacting coasts around the planet.
There is strong scientific consensus about the amount of sea- level rise to 2050 (0.24-0.32 m) and a range of projections to 2100, which vary depending on the approach used and the mitigation measures taken to reduce carbon emissions.
Despite this strong scientific consensus regarding the reality of climate change-related sea- level rise, and the associated need to engage publics in adaptation and mitigation efforts, there is a lack of empirical evidence regarding people's understanding of the issue.
Here we investigate public understanding of the amount, rate and causes of sea-level rise. Data from a representative sample of New Zealand adults showed a suprising tendency for the public to overestimate the scientifically plausible amount of sea-level rise by 2100 and to identify melting sea ic and as its primary causal mechanism.
These findings will be valuable for scientists communicating about sea-level rise, communicators seeking to engage publics on the issue of sea-level rise, and media reporting on sea-level rise."