Question

who gave the concept of global estimate? ​

Answer 1

Global biodiversity is the measure of biodiversity on planet Earth and is defined as the total variability of life forms. More than 99 percent of all species[1] that ever lived on Earth are estimated to be extinct.[2][3] Estimates on the number of Earth's current species range from 2 million to 1012,[4] of which about 1.74 million have been databased thus far[5] and over 80 percent have not yet been described.[6] More recently, in May 2016, scientists reported that 1 trillion species are estimated to be on Earth currently with only one-thousandth of one percent described.[7] The total amount of DNA base pairs on Earth, as a possible approximation of global biodiversity, is estimated at 5.0 x 1037, and weighs 50 billion tonnes.[8] In comparison, the total mass of the biosphere has been estimated to be as much as 4 TtC (trillion tons of carbon).[9]

Answer 2

In 1982, Terry Erwin published an estimate of global species richness of 30 million, by extrapolating from the numbers of beetles found in a species of tropical tree.