The scientists, along with international colleagues, have presented a detailed plan for the monumental effort in the journal Systematics and Biodiversity.
The authors have proposed "an intensive internationally collaborative mission aimed at discovering as many plant and animal species on Earth as possible and mapping their distributions in its biosphere."
"Earth's biosphere has proven to be a vast frontier that, even after centuries of exploration, remains largely uncharted," they wrote.
Scientists estimate about 2 million of Earth's species have been discovered and named, with about 18,000 new plants and animals found each year.
At least 10 million species on Earth are yet to be discovered or accurately classified, they said, whether tiny, large, buried, hidden in collections or in plain sight.
Roughly 30 percent of Earth's species will become extinct this century, the researchers said: "For the first time in human history, the rate of species extinction may exceed that of species discovery."
Time is running out, said Quentin Wheeler, the proposal's lead author and an entomologist and director of the International Institute for Species Exploration at Arizona State University.
"From the 18th century until our appreciation for the pace of biodiversity loss, it seemed that we could make do with fractional knowledge of Earth's species," he wrote. "It is now clear that this was a tragic miscalculation.
"Without exploring, describing and classifying Earth's species we may miss many of our best opportunities to learn from natural selection how to solve countless problems related to our own sustainable survival," he wrote.