Claims that rising sea levels led to a remote island species’ demise is contradicted by evidence that sea levels were meters higher than today a few thousand years ago.
In 2019 Australia’s government announced that climate change – rising seas, specifically – had claimed its first-ever mammalian victim: a rat.
The Bramble Cay melomys lived on an island today situated only 1 meter above sea level. It has been assumed recent sea level changes around northeastern Australia have compromised the Bramble Cay coastal habitat.
But a new study (Köhler et al., 2021) says this same area had 2-3 meters higher sea levels just 7,000 to 4,000 years ago, as there was less glaciation and larger volumes of water in ocean basins during this time period.
This would call into question the explanation that modern relative sea level is the reason why this species disappeared – if it indeed has.
Image Source: Köhler et al., 2021
Additionally, a paper we highlighted here a few weeks ago indicated that the coasts and beaches around Australia have not been shrinking as would be expected with alarming rates of sea level rise. Instead, Australia’s coasts have been expanding (net) seaward at a pace of +0.10 of a meter per year since 1984 (Mao et al., 2021).
And the islands north of Australia have also been collectively expanding in size (Holdaway et al., 2021).
Thus, it would be difficult to imagine why a rat’s habitat would be compromised by coastal progradation.
Image Source: Mao et al., 2021
Image Source: Holdaway et al., 2021
So we once again have another alarmist claim – this time about a climate-change-induced animal extinction – that is contradicted by evidence found in the scientific literature.