ON THE ROAD TO EXTINCTION.

• Author: Grise, Chrisanne

Humans are altering the Earth at an unprecedented pace, putting 1 million species at risk of disappearings. Can we survice without them?

Something was wrong. As tropical ecologist Brad Lister walked through the Puerto Rican rainforest a few years ago, he wondered: Where are all the butterflies? When he'd last visited, 35 years before, there had been hundreds in the air, and his traps had quickly become covered in bugs. Now he and his colleague, Andres Garcia, caught only a few lonely insects, if anything at all.

"We were incredulous," Lister says. "It was clear there had been a catastrophic collapse of the insect population."

Lister's research ultimately showed that 98 percent of the area's ground insects had vanished since the 1970s. Other scientists have had similar findings in different locations; one global review published in February even suggested that insects as a whole might "go down the path of extinction in a few decades."

Then, earlier this year, the United Nations released a shocking report: Insects aren't the only ones in trouble. Humans are transforming Earth's natural landscapes so dramatically, the assessment says, that as many as 1 million plant and animal species are now at risk of extinction. (Including insects, there are an estimated 8 million species on the planet in total.) In most major land habitats- from the savannas of Africa to the rainforests of South America-the average abundance of native plant and animal life has fallen by 20 percent or more, mainly over the past century.

And in September, research published in the journal Science appeared to support the findings by the U.N. There are 2.9 billion fewer birds in the U.S. and Canada than there were 50 years ago, the study says.

Scientists are alarmed by these results in part because of how closely human well-being is intertwined with the fate of other species.

"For a long time, people just thought of biodiversity as saving nature for its own sake," says Robert Watson, the British chemist who chaired the group of scientists that authored the U.N. report. "But this report makes clear the links between biodiversity and nature and things like food security and clean water in both rich and poor countries. "

As more research continues to emerge, people all over the world are beginning to ask: Can anything be done to slow the losses?

'Death by a Thousand Cuts'

There are multiple reasons for the rapid declines, according to the report-but humans are behind all of them...