Climate change is already affecting global biodiversity, and scientists expect the impacts to increase.
- Coral reefs are extremely vulnerable to global warming. They contain microorganisms that are expelled when water temperatures rise, causing the corals to lose color or bleach. More than 16 percent of the planet’s coral reefs have been severely damaged in recent years because of unusually high water temperatures, and many have died.
- Global warming has caused the loss of some 12 billion cubic meters of snow from Peruvian Andes glaciers, where 70 percent of the world’s tropical region ice fields are located. The fate of these glaciers will affect water supplies and ecological habitats across the vast Amazon region.
- The disappearance of 20 species of frogs and toads, including the endemic golden toad from the highland cloud forests in Costa Rica, has been linked to a 30-year warming trend and a severe reduction in dry-season mists. Meanwhile, species from lower elevations are invading the forests.
- A glacial retreat in high-biodiversity regions such as eastern Africa is imperiling watersheds. During the past century, glaciers on Mount Kilimanjaro have lost 73 percent of their mass. Glacial melt water nourishes many alpine ecosystems, and certain desert streamside habitats would completely collapse without it in the dry season.
A variety of habitats from alpine to marine will be modified by global warming.
- Reduced habitat will place some species at greater risk of extinction. They include the Bengal tiger in the Sundarbans Delta region of India and Bangladesh, the mountain gorilla in Africa, and the resplendent quetzal in Central and South America.
- Sea-level rise, caused by increasing ocean temperatures, is expected to result in the disappearance of many low-lying islands along with the extinction of their endemic species. Two South Pacific islands in the state of Kiribati have already disappeared beneath the waves.
- The warming of tropical waters may contribute to the outbreak of animal (species-based) epidemics and may increase the spread of marine disease agents and parasites. One epidemic killed thousands of striped dolphins in the Mediterranean in the early 1990s.
- Climate change is expected to disrupt many ecosystems by making them susceptible to invasion by non-native species. The anticipated spread of red fire ants throughout the southeastern United States, for example, could devastate native flora and fauna.