"I was really stunned by what I saw," Beltrá said. "I do a lot of aerial photography and so we found stranded boats in the middle of huge sand dunes. The river was really, really very low. Millions of fish were dying."
It is not easy for Beltra to show so much tragedy and still keep people engaged. While his work can be difficult at times, Beltra said he remains optimistic that people are paying attention.
"People are getting more and more concerned about the direction we're taking as humanity in the planet," Beltra said. "I always say that in this world there's no Republicans or Democrats. There's not a right or a left. We're all under the same roof. It's our house. We need to take care of it."
Beltrá shot more than 40,000 images in Sumatra. More than 100 of the most striking photographs will be bound in a limited-edition book that will be sent to world leaders, nongovernmental advocacy groups and corporate executies in advance of the Copenhagen Climate Change Conference this December.
With his poignant photography in the hands of some of the world's most prominent figures, Beltra said he hopes rainforest conservation will get more of the world's attention.