The Federal Government has recognized that human-induced climate change has caused the first known extinction of a mammal, a tiny island rodent known as the Bramble Cay melomys.

Environment minister Melissa Price quietly declared the extinction in a note on threatened species released by her office on Monday.  It wasn't the subject of a major announcement, but buried in a listing of species at the bottom.  The Department of the Environment and Energy recommended it for "transfer from the Endangered Category to the Extinct Category".  Environmentalists say this unceremonious dumping denies the importance of the moment:

"The Bramble Cay melomys was a little brown rat," said Tim Beshara, federal policy director for the Wilderness Society to the Sydney Morning Herald.  "But it was our little brown rat and it was our responsibility to make sure it persisted.  And we failed."

The fate of the Bramble Cay melomys has been in doubt for a decade, since the last one was seen.  A Queensland report (.pdf link) in 2016 concluded that the rodent was more than likely "the first recorded mammalian extinction due to anthropogenic climate change" due to extreme storm surges and "climate change-induced sea-level rise" around the tiny five-hectare island where the highest point is only three meters above sea level.

"Business as usual is the death warrant for our threatened animals," said Greens Senator Janet Rice, chair of the Senate inquiry into Australia's animal extinction crisis.  She adds that the Environment Department's release quietly moved the spectacled flying fox onto the endangered category in Monday's update.

"The extinction of the Bramble Cay Melomys should be a national tragedy, and the Morrison government's failure to protect Australia's nearly 500 animals threatened with extinction is an absolute disgrace," said Senator Rice.  "The environment department says it's learned from this extinction and takes extinction seriously, but if it was serious it should be conducting an immediate review of how this happened."

The significance for Australia is that the rodent could very well be a harbinger of things to come.  The waters off the northern coast are warming and rising.  That has caused horrific bleaching along the Great Barrier Reef and forced several Pacific Island nations to prepare contingency plans for climate migration as people are displaced by rising waters.