More than 3 500 animal species are threatened by climate change, according to a new analysis from Oregon State University which was published in the scientific journal BioScience earlier this summer.

“We’re at the start of an existential crisis for the Earth’s wild animals,” lead author William Ripple, a professor of ecology at Oregon State University, said in a statement. “Up till now, the primary cause of biodiversity loss has been the twin threats of overexploitation and habitat alteration, but as climate change intensifies, we expect it to become a third major threat to the Earth’s animals,” Ripple warned.

The researchers used publicly available biodiversity datasets to evaluate the potential threat to 70 814 species across 35 existing classes. The researchers then categorized species by class and climate change risks and found that there were six classes with at least 25 percent of assessed species being “severely” threatened by climate change, including arachnids, single-footed animals and coral animals. Marine invertebrates, which absorb most of the heat generated by climate change, were found to be particularly vulnerable. These marine invertebrates are becoming increasingly vulnerable because of their limited mobility that makes it hard for them to evade adverse environmental conditions.

The 2021 Pacific Northwest heat dome likely caused the death of billions of intertidal invertebrates. Besides invertebrates, there are plenty of other animals that are facing severe risks from the effects of climate change. The study points to a couple of examples: In 2015 and 2016, about 4 million common murres starved to death off the west coast of North America following a severe heat wave that wrecked havoc on their food sources. That same heatwave event also caused a 71 percent decline in Pacific cod. Other heat waves, the study notes, have likely contributed to the deaths of about 7 000 humpback whales in the Pacific.

Because moderate increases in average temperatures can lead to dramatic increases in the incidence of extreme weather, the researchers expect some of these threats will become much more serious in upcoming years. Even more worrying, the study's assessment represented just 5.5 percent of all wildlife species today. That means that the full scope and scale of the threat posed by climate change still remains largely unclear.