It's worth noting, the last time there was this much CO2 in the atmosphere (>400ppm), sea levels were significantly higher. Estimates are all over the map, but most of them put global sea at least 10m above our current levels.

A few sources:

https://www.noaa.gov/news-release/carbon-dioxide-now-more-th...

https://www.nature.com/articles/s41586-019-1543-2?proof=t

https://www.science.org/doi/10.1126/science.1233137

https://royalsocietypublishing.org/doi/10.1098/rsta.2012.029...

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/200...

EDIT: Fix words.