Christopher Trisos, University of Cape Town
The study says that temperature rises above two degrees Celsius will severely affect biodiversity by the end of the century, although it is unclear whether the changes will occur suddenly or gradually.
But the study, which resulted from simulations of climate change data and was published in Nature last week (8 April), suggests that abrupt biodiversity loss will begin as early as the 2030s in tropical ocean ecosystems under scenarios of temperature rises of at least two degrees Celsius.
“If we continue on a high emissions pathway, the risk will spread to tropical and temperate ecosystems on land by the 2050s,” says Trisos, a senior researcher at the African Climate and Development Initiative at the University of Cape Town, South Africa.
Trisos tells SciDev.Net that Africa, Asia and Latin America have large tropical land and ocean ecosystems that are at high risk of abrupt biodiversity loss.
In marine ecosystems along the west coast of Africa and Indo-Pacific region, the disruption could occur within a decade from now, Trisos explains.
Researchers combined the climate data with data on incidence for 30,000 species of animals and plants including mammals, birds, reptiles, amphibians, marine fish, corals, and seagrasses. They then calculated the warmest temperatures that each species had been exposed to between 1850 and 2005 as well as future scenarios for the years 2006–2100.
Abrupt biodiversity loss, Trisos tells SciDev.Net, is extremely dangerous because of local deaths of the tropical land and marine ecosystems.
Tobias Nyumba, a postdoctoral research fellow at the Institute for Climate Change and Adaptation, University of Nairobi, Kenya, says climate change’s negative impact on all levels of biodiversity — from individual organisms to communities of plants and animals — could accelerate the loss and even extinction of biodiversity.
“Global warming will also lead to the general loss of genetic diversity of populations through selection and rapid migration and hence alteration of ecosystem functions and resilience,” Nyumba explains.