Planet-Earth-Buring-Space-FireWe are currently in the midst of the sixth mass extinction event in the history of life on Earth, warns an international research team in a new scientific research review published in the journal Science. The study was conducted by researchers from Stanford University, the University of California-Santa Barbara, Sao Paulo State University in Brazil, the National Autonomous University of Mexico, the Natural Environment Research Council Centre for Ecology and Hydrology in England and University College London. Throughout the 3.5-billion-year history of life, our planet has gone through several mass extinction events, characterized by dramatic drops in species diversity. Unlike prior mass extinctions, which were caused by factors such as natural climate change or asteroid collisions, the current mass extinction is caused exclusively by the activity of a single species: human beings. More