A new study found that mammals, birds and amphibians around the world have lost an average of 18% of their natural habitat as a result of land-use changes and climate problems. In the worst case scenario, this loss could rise to 23% over the next 80 years, according to a study published in the journal Nature Communications.
In the study, scientists from the University of Cambridge analyzed changes in the geographic range of 16,919 species from 1700 to the present day. This data has also been used to predict future changes through 2100 under 16 different climatic and socio-economic scenarios.
Species diversity is known to support important ecosystem functions, from pest control to carbon storage. The vulnerability of species to extinction is strongly influenced by the area of their geographic range. Developing effective strategies for their conservation requires a better understanding of how habitats have changed in the past and what awaits them in alternative scenarios of the future.
It is worth noting that some species are more severely affected than others. An alarming 16% of species have lost more than half of their natural historical range, and this figure could rise to 23% by the end of the century.
Most of all, the ranges of species have decreased in tropical regions. About 50 years ago, the greatest development of agriculture was in Europe and North America. Since then, vast areas of land have been converted for agriculture in the tropics. For example, rainforests were cleared for oil palm plantations in Southeast Asia and pastures in South America.
As humans move deeper into the tropics, the impact on species’ ranges becomes disproportionately large. The reason is the huge variety of species in these areas. In addition, the initially natural ranges of vulnerable individuals are already small.
The study’s findings predict that climate change will have an increasing impact on the geographic ranges of species. Rising temperatures and changing rainfall patterns will significantly change the habitat. Other studies predict that without diminishing human influence on the climate, Amazon forests could transform from tropical to savanna. This will happen in the next 100 years.
Species in the Amazon have adapted to life in the rainforest. If climate change leads to a change in this ecosystem, many of them will not be able to survive, the scientists conclude.