Joy, it is not at all clear from this chart that sea level rise is “already plainly accelerating.” Sea level over the last 100 years is an elusive concept empirically, because the sea is not level and the earth’s crust is in constant motion.
The supposed recent change in rate in this chart is due primarily to the splicing together of two different studies, which may well use different methods. In fact where the studies overlap, it appears that the C&W study does not show the increase, contradicting the UC study. Might this be a “hide the decline” case ? In any case it is simply wrong to claim the acceleration is plainly known, far from it.
Moreover, this supposed rise no more confirms AGW than warming does. The unanswered question is why is it warming? AGW is just one of multiple hypotheses, so warming per se, or its effects such as sea level rise, are not evidence for AGW. Neither is the conjectured energy imbalance. In fact the fact that the oceans are warming, if they actually are, is probably sufficient to explain the imbalance, if there is one. The question would then be why are the oceans warming? Natural causes must be ruled out before AGW can be confirmed.
But then I am skeptical of all of this conjectural noise, presented as facts, which rises far above what we actually know. AGW is a study in false certainty. Your chart is a perfect example of this fallacy.