Drowning World - S1.E62

Ming constructs a dam near the sea of Japan. This diverts the warm currents of the Japenease oceans towards the antartic, causing the polar Ice caps to melt, which results in major worldwide flooding and certain disaster. The Defenders race to the Artic to prevent the glaicers from further collapsing, when they are attacked by Ming's Ice Robots and Garax.

The Defenders do battle with the Ice Robots and are able to fend them off long enough to escape back to the U.S.A, where they discover that Ming's Dam is the source of the worldwide flooding.

Lothar suggests they take out the dam with the untested X-26 missile, whilst Ming takes control of an iceberg and sends it hurtling in the direction of New York City...