Already facing the threat of habitat destruction, hundreds of plant and animal species are now under further pressure from manmade climate change, the IUCN said Tuesday in its updated "Red List of Threatened Species".
The International Union for the Conservation of Nature added 1,840 new species to its catalogue of plants and animals that risk extinction.
The list now contains more than 30,000 species under threat of disappearing.
"Climate change is adding to the multiple threats species face, and we need to act urgently and decisively to curb the crisis," said IUCN acting director general Grethel Aguilar.
"This update reveals the ever-increasing impacts of human activities on wildlife."
The IUCN said it had witnessed genuine declines in 73 species since its last assessment.
The group earlier this year released a devastating look at the state of wildlife on Earth, which made for alarming reading.
More than one million species are now at risk of vanishing as insatiable human demand puts them in danger of habitat loss, overexploitation, pollution and climate change.
Releasing its Red List update in the middle of COP25 climate talks in Madrid, the IUCN said Tuesday it was increasingly clear that climate change on its own was a growing threat.
Rising temperatures have already contributed to the declines of several freshwater fish and sharks.
The latest update showed that 37 percent of Australia's freshwater fish species were threatened with extinction.
Stocks of the Short-tail nurse shark have declined around 80 percent in the last 30 years. Its shallow water habitat is being degraded as the ocean warms.
Dozens of species of birds and plants are now also threatened by rising temperatures, the list found.
The IUCN did highlight a small handful of conservation successes, including the recovery of the Guam Rail, a bird previously listed as extinct in the wild.
"The results of determined conservation actions demonstrate that when governments, conservation organisations and local communities work together, we can reverse the trend of biodiversity loss,” said Jane Smart, global director of the IUCN Biodiversity Conservation Group.
Next year will see two global IUCN gatherings, one in June in Marseille and another in Kunming, China, in October.