Bushfires are a part of life in Australia and they're often deadly. But the scale of these fires is unprecedented. Areas across multiple states have ignited. Australian cities have suffocated in smoke, on some days giving residents the worst air quality in the world. And according to one estimate, a billion animals have been killed. Scientists say climate change is transforming Australia's fragile climate.

60 Minutes CBS (USA) spoke to one of those scientists, Dr Joelle Gergis from the Fenner School of Environment & Society.