Earth could be home to 1 trillion species: study

Earth could be home to nearly 1 trillion species, with only one-thousandth of 1 percent now identified, a U.S. study said Monday.

The estimate, published in the U.S. journal Proceedings of the National Academy of Sciences, was based on data representing more than 5.6 million microscopic and nonmicroscopic species from 35,000 locations across all the world's oceans and continents, except Antarctica.