A new study published earlier this week in the journal Science found that 1 in 6 species of animals and plants will be driven into extinction as a result of global warming by the end of the century.
According to a “business-as-usual trajectory”, if global warming continues to rise at the current rate, once the Earth’s temperature has increased by 2 degrees Celsius, as many as 5.2% of species could die out.
Once the Earth’s temperature has increased by 3 degrees Celsius, 8.5% of species will risk extinction. And once it has finally increased by 4.3 degrees Celsius, as many as 16% of species (1 in 6) could disappear off of the face of the planet.
To make matters worse, Mark Urban, study author and ecology and evolutionary biology researcher at the University of Connecticut, says that “extinction risks from climate change are expected not only to increase but to accelerate for every degree rise in global temperatures. […] The signal of climate change-induced extinctions will become increasingly apparent if we do not act now to limit future climate change”.
The study showed that “extinction risks were highest in South America, Australia and New Zealand, and risks did not vary by taxonomic group”, with South America being the most vulnerable one as 23% of their native species could face extinction.
14% of species could die out in New Zealand and Australia, 6% in North America and 5% in Europe.
Mark Urban analyzed 131 previous studies that used various types of computer simulations built by his peers and discovered that average extinction rate for the globe (all species, all regions) will be 7.9% by the end of the century (it’s currently at 2.8%). That’s how many species are predicted to die because of global warming. “It’s a sobering result” he said.
Scientists who didn’t participate in the study are quick to point out that Urban only took into consideration temperatures, never once looking at other endangering factors such as fires, interaction with other animals, habitat loss, nor considering how evolution could help species adapt to the rising temperature.
John J. Wiens, an evolutionary biologist at the University of Arizona, believes that as bad as Urban’s number is, the real number “may well be two to three times higher”, while Doctor Richard Pearson, a biogeographer at University College London, asked an intriguing question: “What happens to other species in an ecosystem when a species goes extinct?”.
The results revealed that the most affected species will be those with smaller habitat ranges, such as amphibians and reptiles that need specific types of environments to survive.
As it gets warmer, species tend to move closer to the poles and up in elevation to escape the heat. This is not necessarily a good impulse as some species, especially those on mountains such as the American pika, run out of space to move and could end up dying because there’s no place to escape the heat. It’s no different than being on an ever-shrinking island.
Urban hopes the study will help people realize the danger that the animals are facing and start reducing the amount of greenhouse gases released into the air to prevent a future tragedy from happening: “We have the choice […] The world can decide where on that curve they want the future Earth to be”.
Image Source: nwf.org