"Arctic Melt Down" is the story featured in issue #65 of Action Man
Something is melting the ice caps, causing tidal waves and flooding. The United Nations call Action Man for help. The origin seems to be storms from the North Pole, so Action Man goes there.
At the Arctic Circle, Action Man finds Dr X's secret camp, but Tempest finds him, shoots him a ray of lightning and makes him fall from an edge, but he doiesn't notice Action Man saves himself with hgis mountainering equipment.
Back at the camp, Tempest calls Dr X to tell him about Action Man's demise, to which Dr X congratulates Tempest and tells him to continue the storms to flood the world. When a worried henchman asks if they will also drown when the world is underwater, Tempest assures him that they will be safe in Dr X's underwater city and the world will soon be theirs.
Another henchman points Action Man approaching, so Tempest goes to his encounter on a dog sled and tries to fry him with more lightning rays. Action Man climbs a cliff and throws a snowball at Tempest, so a henchman who watches AM shouts "Get him!" which causes an avalanche, burying Tempest and his men. AM believes he has seen the last of Tempest, but Tempest raises his hand from under the snow while the narration box says "Don't count on it, Action Man!"