No, they are being pushed farther apart by the constructive boundary at the Mid-Atlantic Ridge.
Thanks! Another thought I had - glacial rebound. The land, and I imagine the ocean crust, is still rising after it had been depressed by the huge amount of ice resting on it.
Before they figured that out, they thought the water levels were dropping - but it was really the water level meters, stuck in the ocean floor near the shore - were rising!
But if they measure the water level from satellites - that might show the water level rising, but it is really everything rising? Hopefully they are smart enough to take glacial rebound into account.
Manmade CO2 is about 0.12% of the greenhouse effect. That’s really small. I imagine there are numerous other factors than can cause apparent sea-level rise that I’ve never heard them consider such as tectonics or glacial rebound. What about comet ice debris? I wonder what the variability in that is. I could easily see that being a cyclical thing as we pass through different parts of the galaxy/ universe with more or less debris.