Trending Science: Is this climate change’s first big casualty?

On Monday 18 February, the Australian government confirmed what Queensland has known for a few years already. A rodent in northern Australia has been declared the first mammal lost to man-made climate change. Australian scientists have found no trace of the animal.

The Bramble Cay melomys lived solely on a small island on the Great Barrier Reef. It had not been sighted since 2009. Several hundred lived there as late as the 1970s. By 1992, the Queensland state government had classified the species as endangered because of a sharp drop in its population.

So long, little brown rat, we hardly knew you

“The Bramble Cay melomys was a little brown rat” Tim Beshara a spokesman for advocacy group The Wilderness Society told the ‘BBC’. “But it was our little brown rat and it was our responsibility to make sure it persisted. And we failed.”

The confirmation follows the same conclusion reached by the state of Queensland in 2016 in a report published by the University of Queensland. It details failed attempts to find the rodent. Researchers state that a survey effort involving “900 small mammal trap-nights 60 camera trap-nights and two hours of active daytime searches produced no records of the species confirming that the only known population of this rodent is now extinct.”

The state government report blames the extinction on rising seas that destroyed the rat’s habitat. “The key factor responsible for the extirpation of this population was almost certainly ocean inundation of the low-lying cay, very likely on multiple occasions, during the last decade, causing dramatic habitat loss and perhaps also direct mortality of individuals.”

Animals’ greatest enemy

And who is at fault for the island’s increased flooding? We are, of course. “Available information about sea-level rise and the increased frequency and intensity of weather events producing extreme high water levels and damaging storm surges in the Torres Strait region over this period point to human-induced climate change being the root cause of the loss of the Bramble Cay melomys.” The report adds: “Significantly, this probably represents the first recorded mammalian extinction due to anthropogenic climate change.”

Greens party senator Janet Rice who is chairing a senate inquiry into the country’s extinction crisis didn’t hold back on Twitter: “Bramble Cay Melomys extinction is an absolute tragedy.” Another tweet soon followed: “First mammal in world to go extinct from climate change on this gov’s watch. A huge tragedy. Recovery plan wasn’t implemented or reviewed & Morrison gov turned a blind eye.”

More species worldwide will become extinct if temperatures continue to rise. That’s not good news, particularly for Australia, home to large numbers of some of the world’s most endangered species. It also has the world’s highest rates of animal extinction, according to the International Union for Conservation of Nature.