Temperature plays a key role as sea turtle eggs are incubating in the sand. Sea turtles experience a Temperature-Dependent Sex Determination or TSD. When the sand temperature is warmer around 33 degrees Celsius, the eggs develop into female turtles while slightly cooler temperatures below 28 degrees Celsius, cause the eggs to develop as males.
Scientists predicted that as a global temperatures climbed female turtles would be come the majority. As the numbers of female sea turtles increase there are fears that the girls could have a hard time finding mates, but that's a ways off in the future right?
Actually its not as far out in the future as you might think. Jensen et al. released a study in 2018 where they looked at populations of green sea turtles in the Northern and Southern parts of the Great Barrier Reef. They found turtles in the Southern area had a population that was 65-69% female. Even further illustrating their point, they found the Northern population to be 87-99% female. Researchers concluded that it was possible the Northern population would be come 100% female in a few years.
So what then? Considered to be a charismatic mega fauna and beloved by many, it is likely that with this trend in skewed sex ratios, we will see the rise of sea turtle hatcheries where temperature (and other factors their success depends on) are able to be regulated.
Curious about Michael Jensen's research paper? It is free and available for your reading pleasure:
https://www.cell.com/current-biology/fulltext/S0960-9822(17)31539-7