"The science behind a new report in the Proceedings of the National Academy of Sciences journal is complicated, but the evidence is more precise than it has ever been: Sea levels are now rising at a faster rate than they were at any time in the past 2,000 years. For much of the two millenia measured in the study, sea levels were either stabilized or rising at .25 millimeters per year. But right around the end of the 19th century, sea levels started rising at a comparatively drastic 2.1 millimeters per year, and the trend has continued today.
The study marks a huge advancement in the science of measuring sea level changes because for the first time, scientists have recorded a precise and continuous record of sea level changes dating back over two millenia. This record, which the study based on salt marsh microfossil records from North Carolina's coast, shows that sea level changes for the past millenium have correspended to global temperatures. When the world started warming up, sea levels rose. When it cooled, they stabilized."