Aftermath Population Zero, a dark documentary depicting the end of humanity and what the planet will look like after there are no humans left.
Of course, this documentary seems largely like speculation, though it is based on facts and features a number of scientists. Those featured speculate what planet Earth will be like after we are gone and what plant and animal life will be like.
One must consider that humans may never disappear, and if we do there could be a variety of states Earth could be left in. Probably the worst is in a nuclear winter with all the oceans full of plastic.
Sadly the narrator of this documentary, Reginald Eurias Cathey passed away on February 9th, 2018. RIP.