Here's an old trick:
As him/her for assumptions about the business over the same time period: acquisitions, divestitures, regulatory changes, industry trends (yours, business, economy), etc.
The make some projects based on that.
If s/he gives you none, provide your own and assume based on that. This kind of blue sky crap comes around all the time. Bean counters and budget planners ask for. make something up and give it to them in nice little spoonfuls.