Researcher Mark Urban took the first holistic approach to predicting the effect of climate change on species extinction, and made some grim findings.

The numbers showed that for every degree of temperature rise, one in six species will be threatened, and those living on continents with unique climate ranges are most at risk because they need specific atmospheric conditions to thrive, the University of Connecticut reported. The findings were based on a meta-analysis of data from previously published studies.

"We can look across all the studies and use the wisdom of many scientists," Urban said.  "When we put it all together we can account for the uncertainty in each approach, and look for common patterns and understand how the moderators in each type of study affect outcomes."

The study predicted about a three percent species extinction rate based on the current conditions on Earth. If the Earth warms another three degrees Celsius the extinction rate will jump to 8.5 percent, and if global continues on its current trajectory there will be a 4.3 degree rise in temperature by the year 2100; this would result in a 16 percent extinction rate.

Past studies on the effect of climate change on extinction rates have primarily focused on regions such as North America and Europe, but South America, Australia, and New Zealand are most at risk.

"With Australia and New Zealand, we're also looking at land masses that are relatively small and isolated, so that the possibility of a species shifting to a new habitat simply doesn't exist," Urban said.

The recent findings also show extinction rates do not vary across taxonomic groups, which came as a surprise to the researchers.

"We have generally thought that certain groups were more at risk than others, but our results show that all taxonomic groups will be affected as the climate changes," Urban said.

Even species that were not directly threatened by climate change could be affected and show changes in distribution and population size.  

"It's hard enough to predict change, but in the end, we have one climate to contend with," Urban said. "With living things, we are dealing with millions of species, none of which act precisely the same. In fact, we may be surprised, as indirect biologic risks that are not even recognized at present may turn out to have a greater impact than we've ever anticipated."

The findings were published in a recent edition of the journal Science.