Tuesday briefing: What polar bear DNA tells us about a warming Arctic

Polar bears have been clear victims of the human-made climate crisis. Photograph: Russell Millner/Alamy

Good morning. Amid the constant drumbeat of bleak news about the planet’s environment and the accelerating climate emergency, the occasional bright spot still emerges. One example came last week, when researchers published the first statistical evidence that polar bears are changing their DNA in response to a warming Arctic.

But is it really good news that human activity – the burning of fossil fuels and the destruction of habitats – is forcing animals to alter their genetic makeup? The picture, as ever, is complicated.