Oh yeah... very old Sci-fi flick Voyage to the Bottom of the Sea...
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The state-of-the-art nuclear submarine, Seaview, is on diving trials in the Arctic Ocean. Seaview is designed by scientist Admiral Harriman Nelson (USN-Ret). Captain Lee Crane is Seaview's Commanding Officer. The mission includes being out of radio contact for 96 hours while under the Arctic ice cap. The polar ice begins to crack and melt, with boulder-size pieces sinking into the ocean around the submerged submarine. Surfacing, they discover the sky is on fire. After rescuing scientist Miguel Alvarez and his dog at Ice Floe Delta, Seaview receives a radio message from Mission Director Inspector Bergan at the Bureau of Marine Exploration. While piercing the Van Allen radiation belt, a meteor shower set it on fire, resulting in an increase in the global temperature.
The President summons Admiral Nelson to a United Nations Emergency Scientific meeting. Nelson and Commodore Lucius Emery have devised a plan to end the catastrophe. Seaview arrives in New York Harbor two days later. According to Nelson and Emery's calculations, if the increasing temperature is not stopped, it will become irreversible and the Earth will die in about three weeks. Nelson and Emery propose extinguishing the fire by launching a nuclear missile at the burning belt from the Mariana Islands. A nuclear explosion should extinguish the flames, "amputating" the belt from the Earth. Seaview can fire the missile. The chief scientist and head delegate, Vienna's Emilio Zucco, rejects Nelson's plan as too risky. He believes the composition of the belt's gasses will cause the fire to soon burn itself out. Nelson disagrees with Zucco's theory, claiming that his estimated burn-out point is incorrect. However, Nelson and Emery's plan is rejected. The two leave the proceedings intending to get authorization directly from the President himself.
The Seaview races to reach the optimal firing position above the Pacific Ocean's Mariana Trench in time for the needed angle of trajectory. Nelson and Crane attempt tapping the Rio-to-London telephone cable, trying to reach the President. During the cable tapping attempt, Crane and Alvarez battle a giant squid. They can only tap into the London cable, and Nelson learns there has been no contact with the U.S. for 35 hours.
An unsuccessful attempt on the Admiral's life indicates a saboteur is aboard. Alvarez, a religious zealot regarding the catastrophe, is the suspected saboteur. Dr. Susan Hiller, who privately supports Dr. Zucco's plan, is another suspect.
The Seaview's main generator is then sabotaged by a crew member who lost his mind, forcing Nelson to order Crane to proceed while repairs are made despite the risk of traveling without power for the sonar and radar. As a result, the submarine narrowly escapes a minefield left over from World War II. The crew are near-mutiny, to the point that when the Seaview encounters a motor ship whose crew is dead, Captain Crane and the Admiral allow any men who wish to leave rather than continue the mission to sail the derelict home.
Crane begins doubting the Admiral's tactics and reasoning. A hostile submarine pursues them, diving into the Mariana Trench, exceeding its crush depth; it implodes before it can destroy Seaview.
The saboteur has shut down the sub's power. Crane encounters Dr. Hiller, the saboteur, atop the shark tank, as she exits the restricted nuclear reactor core. Her radiation detector badge has turned red, showing she has been exposed to a fatal dose. When asked why, she says to prevent the sub from reaching its target. An explosion rocks the sub, throwing Dr. Hiller into the shark tank. The sharks kill her.
Seaview reaches the Mariana Islands in time to carry out the Admiral's plan. He learns that temperatures are rising faster than projected, proving Zucco's theory is incorrect. Alvarez, believing it is God's will for the Earth to be destroyed, attempts to sabotage the mission by threatening to explode a bomb. The nuclear missile is launched toward the belt by Captain Crane, who does it from outside the sub before Alvarez is aware. It explodes in the Van Allen Belt as intended, driving the burning flames away from Earth and saving humanity.
As the sky returns to its normal color, Seaview turns for home, her mission completed.
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Treating the entire planet as a test tube for various "global fixit experiments" doesn't sound very smart to me... of course we have already done so by burning billions of tons of fossil fuels... but these sorts of solutions have that "we are f'd so what the hell" vibe.
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