Only in the last century did science determine that in the distant future life on earth will be completely annihilated. In several billion years as our sun becomes significantly brighter and hotter, life on earth will face significant extinction pressures.
Eventually, in 4.5 to 5 billion years, the sun will become a red giant ultimately burning all life on earth to a crisp, thus bringing the existence of life to an end. Some models predict that changes in solar activity will result the complete loss of all of earth’s water in as little as 1 billion years causing a much sooner demise of life on earth.
And there are several other natural existential threats that could terminate earth life even sooner.