Exponential or parabolic, the rise is still accelerating. The second derivate of sea level is positive in either case.

Yep, like .2 mm/y^2. Exponentials grow much faster than parabolas. When you see that an exponential changes from almost 0 to something, it will change from something to too big to fit in the graph soon, really soon. Parabolas grow more smoothly. The difference is important to make some realistic predictions.