Complex sentence: In 2056 AD, Earth is in ecologic crisis as a consequence of pollution and overpopulation; wherefore automated interplanetary missions have been seeding Mars with atmosphere-producing algae as the first stage of terraforming the planet.
Split into simpler sentences: In 2056 AD, Earth is in ecologic crisis as a consequence of pollution and overpopulation. Automated interplanetary missions have been seeding Mars with atmosphere-producing algae as the first stage of terraforming the planet.