Climate Change Makes Most Sea Turtles Female And It's Not Good

In Australia's Northern Great Barrier Reef, for the past 20 years, almost all of the green turtle hatchlings that dug themselves out of the sand to flipper-flop into the ocean have been female. 

According to the research published by Current Biology and led by researchers at the National Oceanic and Atmospheric Administration, no one had predicted this.

"This is extreme—like capital letters extreme, exclamation point extreme," NOAA's Camryn Allen, a research biologist and one of the lead authors, told National Geographic. "We're talking a handful of males to hundreds and hundreds of females. We were shocked."

The temperatures of where sea turtles lay eggs are what determines their sex. Colder temperatures produce more males, with more and more females hatching as the sand heats up. As the temperatures have been warming, as much as 99 percent of the newborn turtles have been female.

Climate change is only one of the ways that mess with the ecosystems where turtles reproduce: Sea level rise and bigger storms erode nesting beaches, making it harder for turtles to find safe spots to lay their eggs. Sometimes it's so warm, none of the eggs in the nest hatch.

However, Jacques-Olivier Laloë, an associate research fellow at Deakin University, still has hope:

"They've been around for millions of years, and they survived the catastrophic event that wiped out the dinosaurs, so I have a lot of faith in them,” he said.