- As Earth Day approaches, Conservation International (CI) is drawing attention to a precious corner of the world that will likely be destroyed by global warming within our lifetime.
The Succulent Karoo hotspot, located on the western edge of South Africa and Namibia, is one of the most vulnerable of the world's 25 biodiversity hotspots. Using climate change computer models, scientists predict that warming and drying trends could devastate the area's remarkable plant diversity.
Some of the world's most striking and unusual plant species thrive in this arid region, splashing the spring landscape in brilliant oranges, yellows, purples, and pinks. Endemic varieties of euphorbias, aloes, and iceplants reside here; about 2,000 of the nearly 5,000 plants found there occur nowhere else on Earth. Plant collectors around the world trade many of these plants as ornaments, and several plants have recently been discovered to contain medicinal properties.
Biodiversity hotspots are biologically rich areas that are under extreme threat. Together, they contain more than 60 percent of terrestrial biodiversity on just 1.4 percent of Earth's land surface. "The global community needs to act immediately to reduce greenhouse gas emissions, and be proactive in designing conservation systems to prevent biological collapse in this and other hotspots," said Lee Hannah, a scientist in the Center for Applied Biodiversity Science (CABS) at CI. "The Succulent Karoo is the first hotspot we have modeling results for, and already we see serious cause for concern."
Scientists at the National Botanical Institute, the University of Cape Town, and CABS have been studying the possible impacts of climate change on the survival and distribution of South Africa's indigenous plants. They predict that the Karoo, which has the richest succulent flora in the world, will be eliminated in all but tiny patches possibly as early as mid-century if present emissions trends continue.
"These results surprised and appalled us," said Guy Midgely, project leader of CABS in Cape Town. "We are currently working with policy makers to determine how to cope with these changes." Existing pressures in this region, such as overgrazing and mining, will be exacerbated by man-made changes in climate. Species in this tiny hotspot rely on the low but fairly reliable winter rainfall to survive, and warming and drying would cause the hotspot to disappear.
CABS recommends that protected areas, as well as land that connects these areas, be established quickly to help safeguard species ranges as they move with climate change. Scientists are not sure how long such improved systems can protect nature without emissions reductions, but the Succulent Karoo modeling shows that large-scale losses may be much nearer than previously believed.
Established at CI in 1998, CABS serves as an early warning system by forecasting impending biodiversity crises. CABS targets the biodiversity hotspots, major tropical wilderness areas, and key marine ecosystems, gathering world leaders in science, technology, economics, conservation, and other disciplines to develop action plans and quickly counter threats in these critical habitats.