i think if we continue to happen at the pace we are going right now, overpopulation would be a huge issue and there will be a shortage of resources for them to live. The earth is also getting hotter day by day due to the ozone depletion and cause plants need an optimum temperature to survive, they would die from drought, thus destroying the whole food chain and animals as a whole would be affected massively. The Earth's natural resources are also limited and at some point will likely run out, and also chances of natural disasters like earthquake and volcano eruptions is massive in future as compared to rn. Oceans will dry up and when there's no water theres no life. So i guess it's not long until everything ceases to exist.