Time travel, through speculative wormholes or at the edge of a black hole, may be theoretically possible given certain interpretations of general relativity; but as far as we know, no device can instantly teleport us forward and backward in time.
However, let's imagine that you, by some miracle, stumble across an abandoned "time machine" capable of traveling any number of years into the past or future.
After such a profound discovery, you assemble a team of researchers to travel with you through time and collect data on the future of our planet.
On the day of your expedition, you and your team enter the machine for the first time, equipped with research tools and safety suits that protect you from whatever the future may hold.
The doors of the time machine suddenly slam shut behind you.
Blinding lights flash all around as the cabin begins to shake.
Over your head, a screen displays the years rapidly flying by, climbing higher and higher until the dials stop turning, the lights stop flashing, and the cabin becomes very still.
You and your team have been transported one billion years into the future.
The doors of the time machine slowly open, revealing a landscape entirely different from the lush natural world you left behind.
Earth has become a superheated desert stretching as far as the eye can see.