We have been taken in by the fundamental misunderstanding that the effects of global warming and climate change will not be felt within the next few decades. That's the conclusion of a recent study, conducted by the University of Arizona.

Almost half of all the species investigated in the study are already affected by "local extinction," a term used whenever a species no longer occurs in its native habitat, according John Wiens, one of the authors.

The evolutionary biologist and his team published the results of their investigation in the journal PLOS Biology. They claim that of 976 species studied, 450 are no longer living in their native regions. The results apply for regions where higher than average temperatures are already being measured, including all over Asia, Europe, North and South America, and Africa.

For their investigation, Wiens and his colleagues evaluated other studies focusing on changes in the number of species in certain areas over the past few decades. In some cases, they had completely disappeared.

"Local extinctions related to climate change are already very common," Wiens writes. "Even given the relatively modest rise in global temperatures that has occurred so far."

The global average temperature is now about one degree higher than in pre-industrial times. The researchers expect a dramatic impact on biodiversity if the average temperatures continue to rise.