text: Emeritus of Abundance's last ability checks at the moment it would trigger to see if you control eight or more lands. If you don't, the ability won't trigger at all. It's not possible to put lands onto the battlefield during your declare attackers step in time to have the ability trigger. If it does trigger, the ability will check again as it tries to resolve. If you don't control eight or more lands at that time, the ability won't resolve and none of its effects will happen.