Josh Willis of NASA explains the thermodynamic process of sea level rise, explaining how water takes up more room as it heats up, as well as how extra water is added to the ocean as glaciers and ice sheets melt.
“Over 90% of the heat trapped by GHG is being absorbed by the oceans; when that happens seawater expands and this helps drive sea level rise.”
Globally, sea levels have gone up about 6 centimeters over the last 23 years, as shown in the animation. Orange and red colors mean that sea levels have gone up; blue and white means that levels have actually dropped. Off the West coast of the US, sea levels have decreased due to cooling from the Pacific Decadal Oscillation. Yet, as the diagram shows, most places have risen.
In the Western Pacific in particular, sea levels have risen greatly. This is because of heat being pushed from east to west across the Pacific.
Sources: The Washington Post
, Reporting Climate Science