A study published today in the academic journal Science says that one out of every six species on Earth is at an increased risk of extinction because of the effects of climate change.
Currently, the global extinction risk is at 2.8 percent of species, but increases to 5.2 percent with just a 2°C temperature rise. That 2°C rise is the internationally-agreed upon goal. Many scientists, however, now feel that goal is unachievable, and the global temperature rise will be much greater.
According to study author Dr. Mark C. Urban, “if we follow our current, business-as-usual trajectory … climate change threatens one in six species (16%).”
The regions with the highest risk of mass extinctions are South America (23%) and Australia and New Zealand (14%). North America and Europe faced the lowest risk, at five and six percent, respectively.
Urban also found that endemic species, or ones that only live in a specific region, are at a greater risk than nonendemic species. “We urgently need to understand how [habitat] reductions determine future extinction risk better in order to predict accurately both the number and timing of future extinctions,” wrote Urban.
As climate change affects species’ habitats, they will have to “disperse into newly suitable habitats,” something easier said than done as “species-specific dispersal” increases the extinction risk from 6 percent to 10 percent.
Urban also pointed out that, although the risk of extinction increases as temperatures continue to rise, the number of species affected by climate change will be much greater than those that face extinction.
“Even species not threatened by extinction could experience substantial changes in abundances, distributions, and species interactions, which in turn could affect ecosystems and their services to humans. Already changes in species’ phenologies, range margins, and abundances are evident. Extinctions, although still uncommon, are increasingly attributed to climate change.”
For every degree rise in global temperatures, the risk of extinction not only increases but actually accelerates, said Urban, adding that “climate change-induced extinctions will become increasingly apparent if we do not act now to limit future climate change.”