In this context the world global refers to all the people in the whole world more than physical world itself.
And the world potential has some similar meanings you can use in different contexts.The meaning for this word you thought is likely to be used in a context related to physics or generally science.
In this context the word potential was used as a synonym of the word possible.And the definition for this sense from Oxford Dictionary is that
(often potential for/to do something) The possibility of something
happening or of someone doing something in the future.
And some related example sentences are
They were of course unaware of the latent potential for economic
growth just around the corner.
It has experienced strong growth in the past three years and has good
potential for future growth.
the crane operator’s clear view reduces the potential for accidents.
So the organizers in this forum forecasts and takes attention how possible tourist movements for the future can affect socially and economically a country or a city which has a potential to be visited by millions of people.