Over the years I have read where humans are using up to 11 "Earths", and here 1.5 or so. It really depends on if you are looking at the depletion/regeneration rates of everything.
My research has indicated that we are using up some resources at 100 times their regeneration rate, and oil and coal at 500,000 times their regeneration rate. Pollution is roughly 1000 times the natural systems' absorption rate on average.
So, population overshoot is way past sustainable long term, by up to 1000 times. Unless people clean up their act within 8 years or so. Rotsa ruck!