In 1983, Czechoslovakia (and partly West Germany) shot The Visitors, a science-fiction series that I liked a lot - and so did many other Czechoslovak and German viewers.
Click here for the 1st part; warning: DVD stability issues. The user has posted all episodes.
In May 2484, the United Nations' top supercomputer, the Central Brain of Mankind (CBM, not to be confused with Commodore Business Machines) or CML in Czech, calculates that a comet will nearly collide with the Earth in half a year. The distorted orbit would lead to a catastrophic climate change.
The United Nations employ a time machine (an enhanced SUV) to send a stealth expedition back to 1984 when a little boy, Adam Bernau, celebrates his 11th birthday. Yes, your humble correspondent was born in 1973. Adam Bernau would later win a physics Nobel prize.
The science historians in 2484 believe that the fire in their house burned and destroyed Bernau's documents that describe a method how to easily move whole continents. (Adam actually tore the notebook apart before the fire, to impress his sweetheart.) This method could save life of billions of people and animals on Earth in 2484.
The Central Brain of Mankind experiences a couple of glitches that affect the expedition. For example, the expedition of science historians etc. receives old banknotes that are no longer valid. After lots of adventures, the expedition largely fails.
By an accident, a simple-minded old chap, "Grandpa Drchlík", who was mentioned as a childhood inspiration and "The Great Teacher" in Bernau's memoirs accidentally gets to the time machine and returns to 2484 with the expedition. In this final video, he manages to solve the whole crisis:
Video by klimaskeptik.cz. Music by Karel Svoboda
Don't be afraid, the life in 2484 will be OK. For example, the amarouns will be among the people's most favorite foods. These jelly substances that you can cook out of a pill and a paste contain all the nutrients and flavors from many traditional foods. See 400+ YouTube videos from the series.
It's kind of fun that already back in 1983, the authors of the show figured out that the future Armageddon threats would be based on computer models and these models would be flawed because of the computers' lack of balance.
The series was shot during communism and the future society was probably a sort of communism but you couldn't tell: it superficially looked just like the kind of United Nations-centered global system that many Western politicians are trying to build today, 25+ years after the series was shot.