8 billion people is considered by climate scientists to be overpopulated. We consume more resources than the Earth can replenish and still retain a balanced atmosphere and ecosystems. We would need to reduce our total to about 5 million in order to maintain the balance in this current round of evolution. We also need to switch from fossil fuels to renewable energy from sun, wind and hydro. There are lots of other solutions we need to get into as quickly as possible. It will take everyone's efforts around the globe to make a sufficient difference to survive.
Element 99 