Filling the global biodiversity financing gap will require significant investments from financial markets, which demand credible valuations of ecosystem services and natural capital. However, current valuation approaches discourage investment in conservation because their results cannot be verified using market-determined prices. Here, we bridge the gap between finance and conservation by valuing only wild animals' carbon services for which market prices exist. By projecting the future path of carbon service production using a spatially explicit demographic model, we place a credible value on the carbon capture services produced by African forest elephants. If elephants were protected, their services would be worth $20.8 billion ($10.3 to $29.7 billion) and $25.9 billion ($12.8 to $37.6 billion) for the next 10 and 30 y, respectively, and could finance anti-poaching and conservation programs. Elephant population growth would generate a carbon sink of 109 MtC (64 to 153) across tropical Africa in the next 30 y. Avoided elephant extinction would also prevent the loss of 93 MtC (46 to 130), which is the contribution of the remaining populations. Uncertainties in our projections are controlled mainly by forest regeneration rates and poaching intensity, which indicate that conservation can actively reduce uncertainty for increased financial and biodiversity benefits. Our methodology can also place lower bounds on the social cost of nature degradation. Poaching would result in $2 to $7 billion of lost carbon services within the next 10 to 30 y, suggesting that the benefits of protecting elephants far outweigh the costs. Our methodology enables the integration of animal services into global financial markets with major implications for conservation, local socioeconomies, and conservation. [ABSTRACT FROM AUTHOR]