Well at least if you do jump ahead and find a wasteland of wreckage you know the human race done fucked up. At least you can come back with that knowledge of well it was for naught. Unless you then backtrack to find the events that made that happen and try to change that in the present.
The problem is that even though you might have the knowledge you could also come back after being exposed to nuclear fallout or radiation. Of course their are other issues with time travel that even includes trips to the past. Arriving in front of a moving car or landing someone in the middle of tornado. This is why in "Back to Future" they went to the mall. Doc Brown went somewhere where he felt it would be safe when going to the past because it was where nothing but open farmland was around back in the 1950's.
Jason