U.S. scientists say species are becoming extinct thousands of times faster than they have historically, and that is posing problems for humanity.

The statistical analysis led by University of California-Santa Barbara Associate Professor Bradley Cardinale concludes both the number and varying types of species are needed to maintain ecological balance and "services."

"By combining the results of more than a hundred studies performed over two decades, we were able to conclusively show the extinction of species from our planet will change the way pests and diseases are controlled, organic wastes are broken down and recycled, food is produced by ecosystems, and water is purified," Cardinale said.

Cardinale said a third to half of all the species now on the planet are expected to be lost during the next 100 years, primarily due to the cutting of rainforests, development and pollution.

The research appears in the journal Nature.