What will earth be like in one billion years?

Well, much will have changed - obviously.

• After about 250 million years - continental drift will probably cause all of our present continents to fuse into a single giant super-continent as the pacific ocean gradually shrinks. Exactly how this will play out is uncertain - but North America will almost certainly hit Eurasia.
• After around 500 million years - that gigantic continent will have been ripped apart again - it’s unclear what new continents might form from it.
• At intervals of around 500 million years, large gamma-ray bursts happen close enough to the Earth to cause mass-extinction events if they happen to point in our direction. We can expect this to happen a couple of times over the coming billion years…but it’s a matter of chance whether we get cooked.
• At around the same time, the sun will start to become gradually brighter - the consequences of this are huge - but at some point it’ll get hot enough to disrupt the carbon cycle and to start pouring water vapor into the air. That can cause a run-away global warming effect so that within about 600 million years, plant life will likely be impossible - and the knock-on effects of that would probably end all life on Earth by about 800 million years due to all of the oxygen in the atmosphere having been converted into CO2.
• And at 1 billion years, the sun will be about 10% brighter than it is now - the average temperature will be up to 48 deg C. This will cause all of our oceans to evaporate - except perhaps at the poles.

Over this time, the sun will have orbited the Milky Way galaxy about four times.

Interestingly, a billion years is considered to be the likely life of the two “Golden Records” that were placed aboard the Voyager 1 & 2 space probes…and these may be the last remaining traces of humanity in the universe.