There have been plenty of these conferences over the years. A few stand out, as pivotal/important, usually because of who came, who sponsored it (and why) and what was said. Particularly important were the Villach 1985 conference, the Toronto 1988 conference and the 2009 “4 degrees” one.
But we can hold as many conferences as we like, they don’t change the underlying trajectory or power relations. Imho, every scientific conference could usefully have emblazoned on its programme the words of Sherry Rowland, co-discoverer of the ozone problem;
“What’s the use of having developed a science well enough to make predictions if, in the end, all we’re willing to do is stand around and wait for them to come true?”
(See the lovely Real Climate piece about Rowland.)