"More than 99% of all species that ever lived on Earth, amounting to Billions of various species, are estimated to have died out."
The Earth has been a constant rotation of various species living and going extinct. The idea that the Human Species won't join this fate doesn't gel with Earth's Billion Year History. Yes this is a "Life" Planet but that doesn't mean we get to stay forever. I agree it will be weather that causes the most damage. As for us not making out of this Century. Even with weather events or Nuclear war, There still may be a small colony of survivors that could keep the human speices going. Like Dr. Ian Malcolm of Jurassic Park said. "Life Finds a Way". With that said, Humans have survived a lot including deadly plagues and other weather events. It may not be 2100 but I do think the Human species could definitely be on the clock.
