Great herds of elephants once crisscrossed Africa, and scientists have no doubt that they shaped the landscape, ecosystems and — as recent science has shown — the balance of carbon. Though it’s difficult to be certain of exact numbers, some scientists muse that over the past five centuries, humans have driven a loss of 98% of the continent’s elephants. A more recent, often-cited figure from the IUCN, the global wildlife conservation authority, put the continent’s elephant population at 1.3 million in the 1970s. Research since then has suggested that overall numbers of savanna elephants (Loxodonta africana) have dropped by 70%, driven by hunting and habitat loss. Their forest cousins, Loxodonta cyclotis, have likely slid by 90%. As scientists have begun to uncover the interactions between carbon and big animals like elephants, there’s a been a push to “rewild” landscapes for the benefit of the climate. The ocean’s massive whales similarly offer that potential. As the largest animals that have ever existed on Earth, their bodies alone serve as substantial reservoirs that could keep climate-warming carbon out of the atmosphere over the course of the decades (or more) that they live. Other research has sketched out a whale pump: Whales’ nutrient-rich waste also supports phytoplankton, which absorb large amounts of carbon dioxide. Cetacean contributions to carbon sequestration continue even after they die, as their bodies sometimes sink to the ocean floor, where a range of deep-sea organisms feed on them, keeping that carbon out of the atmosphere. Centuries of hunting have…This article was originally published on Mongabay
