Biology
How many species have been identified on Earth?
~8.7 million estimated
How many species have been identified on Earth?
About 8.7 million eukaryotic species are estimated to exist on Earth. Of these, only around 1.2 million have been formally described. Scientists discover roughly 15,000–18,000 new species each year. At this rate, cataloguing all life would take another 480 years.
Source: Mora et al. (2011), PLOS Biology