The film was produced as a collaboration between Stevens, Leonardo DiCaprio, James Packer, Brett Ratner, Trevor Davidoski, and Jennifer Davisson Killoran.

At the European premiere in London in October 2016, DiCaprio introduced the film as follows: Before The Flood is the product of an incredible three-year journey that took place with my co-creator and director Fisher Stevens.

We went to every corner of the globe to document the devastating impacts of climate change and questioned humanity's ability to reverse what may be the most catastrophic problem mankind has ever faced.

DiCaprio repeatedly references a 15th-century triptych by Hieronymus Bosch, The Garden of Earthly Delights, which, he explains, hung above his crib as an infant, and which he uses as an analogy of the present course of the world toward potential ruin as depicted on its final panel.

[12][13] The interview with British-born astronaut Piers Sellers, a NASA scientist who flew on three space missions, discusses his desire to publicize the perils of global warming in the short time he expected he had remaining to live, as he had stage IV pancreatic cancer as he was being filmed.

[14] Along with DiCaprio, the documentary's subjects include Piers Sellers, Barack Obama, Pope Francis, Sunita Narain, Anote Tong, John Kerry, Elon Musk, Alejandro González Iñárritu, Johan Rockström, Greg Mankiw, Gidon Eshel, Farwiza Farhan,[15] Ian Singleton,[16] Lindsey Allen,[17] Jeremy Jackson,[18] Thomas Remengesau Jr.,[19] Alvin Lin,[20] Ma Jun, Michael E. Mann, Philip Levine, Jason E. Box, Dr. Enric Sala,[21] Michael Brune, and Ban Ki-Moon.

The website's critics' consensus reads, "A fervent call to action where there is no time to waste, lest our future be left in the mud; Leonardo DiCaprio makes it his mission to deliver this urgent message Before the Flood.

[34] Variety praised the fact that "given the sincerity of its message, its ability to assemble such a watchable and comprehensive account gives it an undeniable urgency," stating that "where the film succeeds the most is by focusing on the ground-level victims of climate change, whether the polar bears of the Arctic, or the inhabitants of island nations like Kiribati.