While global climate change is proving harmful to many plants and animals in a variety of ways, for some creatures, it’s actually proving helpful. For most creatures, increasing temperatures from global warming results in moving to other locations or struggling to survive. For Swedish sand lizards, however, it’s actually a good thing.


Since reptiles are cold blooded, external temperatures have a huge impact on them, determining how active they are, and influencing their lifecycles. For the Swedish sand lizards, increasing average temperatures over he last fifteen years has resulted in females laying eggs earlier in the year, which presumably gives their young more time to feed and grow before the cold season moves in, because earlier egg laying correlates to better overall health for sand lizards. The sand lizards benefit from warmer temperatures because that means they can be more active earlier in the year. But the same isn’t true everywhere.

Despite being cold blooded, reptiles still have optimal body temperatures, and being too warm isn’t good for them either. Most scientists have been predicting that increasing global temperatures will be bad for reptiles, especially in the tropics. That’s because, in the tropics at least, the temperature is already pretty optimal for many species of reptile, so if it gets any hotter, they’ll start to suffer.

But the environments that reptiles live in vary, as do the average temperatures, and that’s important to keep in mind. Increasing temperatures in Sweden is good for reptiles, even if it’s bad in the tropics. What we need to do is study reptiles in other parts of the world and see how they’ve fared in warming environments. Sweden is pretty far north, but it’s possible that rising temperatures are benefiting lizards further south as well. It also shines some light on the fact that climate change doesn’t affect all creatures in the same way.