By next year governments should have clear signs on how accurate this model is if food production and industrial output decrease by a significant amount which should also shock the economy.
I say governments should know by next year not the public because looking at the sources for the data it seems like there is a two year delay between the most current data and the present. We will probably be left in the dark until the collapse has already started.
I would not put too much faith into this graph to predict a specific date for the peak.
However what we can see from this graph is the inflexion of the curve, the growth slowed down and we already see the effect of it.
We are reaching the peak, it might plateaus for a few years before a slow decline or we could have a sharp decline happening before the end of the year.