The global sea level is currently rising.
From 1900 and 2016, the sea level rose by 16–21 cm (6.3–8.3 in).
The factors that has contributed to the rising sea level are: Thermal expansion and the melting of glacier.
As the global temperature rise given to the rising in greenhouse gases produced by human activities, more heat is trapped in the atmosphere, the temperature increase.
As the temperature rise, the sea water would expand, hence causing the rise of sea level.
In addition, the glacier in North Pole, South Pole and Antarctica has melted due to the heat, increasing the amount of sea water, contributing to the rising sea level.
Hope it helps!