90% land, huh? That would be interesting. The planet then would lack the moderating influence that oceans and ocean currents have on land masses. The air would be much drier. In fact, the whole planet would be a near desert. River systems would be dramatically decreased. Yet you could still do a lot towards reaching your goal if you kept altitude in mind. In fact, you could make a fair amount of the western hemisphere below sea level, preferably inland areas to protect it from flooding from the small seas and lakes. The eastern hemisphere would be very high above sea level. Think of the Andes in Ecuador and Peru. Even at the equator, they're frozen. The summit of Mt. Kilimanjaro come to mind too.