If the polar ice caps melt most of the coastal areas of the north american continent will be submerged. In fact, the Kevin Costner vehicle, Water World was a fairly accurate depiction of a world lacking polar ice. No, but seriously, the results would still be catastrophic. A rise of a couple meters would flood the streets of many coastal cities, necessitating their evacuation. Low-lying countries such as many in Indonesia could be almost entirely submerged. The new standing water would be ideal for the breeding of mosquitos and other insects, spreading diseases such as malaria.