We have defined the Biosphere Quality Index (BQI) as the total quality of the Earth’s common biosphere. The BQI reflects the results of two opposing sets of forces, the downward forces that reduce biosphere quality (the overall condition of our biosphere), and the upward forces that increase biosphere quality, causing the biosphere to improve. At present, the downward forces outweigh the upward forces as a result of the preponderant effects of human activities. This means that we are not living sustainably, by no means a new consideration.