. One sixth are at risk of extinction due to climate change. Current climate change policies must be changed. An American scientist says that Australia, South America, and New Zealand are most likely to suffer the greatest loss. After crunching numbers, Mark Urban, an associate professor in the Department of Ecology and Evolutionary Biology at University of Connecticut wrote in Science that every degree the world’s temperatures rises, there will be more species disappearing. The likelihood of species disappearing is greater for continents with unique climates. These regions are home to native species which can only survive in a very limited environment. These regions have not been studied much. The extinction of the nursery frog. Reptiles and amphibians are particularly vulnerable. Image: today.uconn.edu. Prof. Urban did a meta-analysis using information from previous published studies. Urban reported that future temperature increases could threaten one out of six species, if climate change policies are not modified. Professor Urban claims that unlike other studies which focused only on survival of specific species, his study is unique in its holistic approach. Professor Urban stated that “we can examine all of the studies and draw on the knowledge from many scientists.” If we take all the data and combine them, we can adjust for uncertainty and find common patterns. This will allow us to understand the effects of moderators on outcomes. The study shows that species extinction rates rise with increasing temperatures. Based upon current conditions, it predicts a 3% increase in the rate. The extinction rate will rise to 8.5% if the planet heats another 3 degrees Celsius. If global warming keeps on its current upward trajectory, there will be an additional 4.3 degC increase in the temperature by the end century. This would result in a 16% rate of extinction. One in six species. Professor Urban stated that he used a global approach to his analysis because it is difficult to compare previous studies from different authors. There were significant differences in the studies, such as geographic locations, species studied, methods used and assumptions. It was difficult for species to be compared because the findings were inconsistent. Professor Mark Urban in Alaska with an aufeis sheet. Aufeis refers to ice which forms in layers along streams during winter. It is decreasing as the climate warms. Photo: Mark Urban. The most endangered species in Australia, New Zealand, and South America. While studies on the impacts of climate change tend to focus on Europe and North America (mostly), he said that the biggest risk of species loss is found in Australasia, and South America. Because of the unique climates on these continents and many native species that are restricted in their ranges of survival, the risks to Australasia/South America are particularly concerning. The risk for extinction of native species, like reptiles or amphibians, is 6% greater than that of non-native species living in the area. Professor Urban stated that Australia and New Zealand are also taking into consideration land mass that is relatively isolated and small so that there are no chances of species moving to new areas. South America, Australia and New Zealand are the most at risk (14 to 23%),, while Europe and North America have lower risks (5 to 6%) Relative risk is indicated by colors. These bar graphs show 95% the CIs as well as how many studies were performed (n). (Image from Science) Similar extinction rates across taxonomic categories Prof. Urban was shocked to see that the extinction risk did not differ significantly by taxonomic category. According to Urban, “We had assumed that some groups are more vulnerable than others. But our research shows that all taxonomic group have similar extinction rates.” Other species that may be at high risk of extinction will likely see significant drops in their population and distributions, as well as changes in how they interact with other species. The author said that this could impact ecosystems and crop yields as well as the spreading of disease. Professor Urban stated that while it is difficult to forecast change, there will only be one climate. Living things are subject to millions of species. Not all of them act in the exact same way. We may even be surprised that indirect biologic risk may have greater consequences than we thought. Science. Published May 1, 2015. DOI: 10. 1126/science.aaa4984.
