Rule variant to discourage no islands strategy

I was thinking of rules variations to discourage the no islands strategy, while still having it be viable early to delay taking damage. My idea is:

"If you would discard an island while you have no islands in play, you lose the game."

I was hoping to get some thoughts on this. Does it seem too severe? Instead of losing the game, should you take 4 damage? I look forward to reading your responses!