Life for newborn sea turtles is a brutal fight for survival.

Sea turtles hatch from eggs their mothers lay in sand nests they dig on warm beaches. When they all emerge simultaneously, the sand covering the nest looks like it’s bubbling. So-called “turtle” boils are cues for predators like foxes and birds to descend onto the beach and lie in wait to snack on on the baby turtles as they make a mad dash to the ocean. It’s not clear how many hatchlings get eaten before they make it to the water, but those that do the first years of life “mostly hiding and growing” because they’re so vulnerable, according to the National Oceanic and Atmospheric Administration. Only about one in 1,000 to 10,000 actually make it to adulthood.

Unfortunately, it’s getting tougher for these little guys to make it out of the nest at all: rising beach temperatures resulting from climate change are killing baby sea turtles before they even hatch.

According to Oceana, a Washington, DC-based nonprofit dedicated to marine conservation, rising sand temperatures have already killed off entire nests on beaches in Florida and Costa Rica. “We’re seeing more dead eggs,” Jeanette Wyneken, a biologist studying sea turtles at the Florida Atlantic University, told Oceana. “And when we do get turtles hatching, they’re often heat stressed: They may hatch and crawl to the water, but then die.” The strain of surviving at elevated temperatures drains them of the energy their tiny bodies need to travel far enough to start feeding.

Rising temperatures are a threat to these creatures in more ways than one. For sea turtles (and many other reptiles) the temperature of the sand the eggs develop in determines sex (paywall). Typically, sands above 29.5°C (85°F) produce female turtles and cooler temperatures around 28°C (82°F) produce males. So as temperatures have warmed, conservation scientists have found that females have begun to outnumber males by nearly four to one in some nesting locations.

Scientists aren’t sure what makes for a healthy ratio of male to female turtles—they only recently started studying these numbers in response to climate change. But theoretically, an all-female population would eventually die out because they couldn’t reproduce.

The demise of entire turtle nests due to heat, though, would accelerate the die-off of turtle populations Prior research has shown that when sand reaches 35°C (95°F) (pdf) or hotter, turtles eggs are not able to hatch at all. It’s unclear how many unhatched turtles die as a result of each degree warmer their nests are, but the problem is likely to only get worse as global temperatures increase.

Scientists are now desperately trying to devise ways of lowering sand temperatures cooler. Some have tried to manually shade or slosh chilled water over turtle nests to try to cool them down, although it would take a massive effort likely involving both scientists and local communities to do this for every nest. Additionally, scientists aren’t totally sure why turtles nest on some beaches and not others, making it harder to predict which beaches would need extra monitoring.

Six of the seven known species of sea turtles are already classified as either vulnerable or endangered by the International Union for Conservation of Nature. If sand temperatures continue to rise—as they undoubtedly will without global, concerted efforts to mitigate climate change—these sea turtles could become another victim of humanity’s destruction of life on the planet.