Yasuni National Park holds somewhere around 846 million barrels of crude oil in the Ishpingo-Tambococha-Tiputini oil field, roughly 20 percent of Ecuador's proven reserves. It also holds records for almost every measure of tropical biodiversity that scientists know how to count. Scientists have documented 655 tree species in a single hectare, more than the total combined for the United States and Canada. UNESCO designated it a biosphere reserve in 1989. About 4,000 plant species, 173 mammal species, and 610 bird species live in the park. It contains more insect species in one hectare than exist on the entire continent of North America. Twenty-three globally threatened mammal species live there, including the giant otter, Amazonian manatee, pink river dolphin, giant anteater, and Amazonian tapir. Ten primate species. And, critically, two groups of Waorani people, the Tagaeri and Taromenane, who live in voluntary isolation and reject all outside contact.

Luis Fierro had proposed something similar in 1994, the idea that Ecuador's national parks should be developed for their renewable resources rather than stripped for their oil. Correa formalized the approach in 2007. The initiative asked the international community to pay Ecuador 50 percent of the oil's value, $3.6 billion over 13 years, through a mix of public and private contributions. In return Ecuador would permanently ban drilling in ITT. The funds would seed Ecuador's transition to a sustainable economy, financing renewable energy, protecting biodiversity, and supporting indigenous communities. Leaving the oil underground would avoid 410 million metric tons of CO2 emissions. Earth Economics estimated the net present value of the park's environmental services at $9.89 billion. The pitch attracted high-profile backers. Leonardo DiCaprio and Edward Norton endorsed it. Ban Ki-moon, then UN Secretary-General, supported it publicly.

By 2012, only $200 million in pledges had materialized. The Ecuadorian government briefly announced it would move forward, but the commission Correa formed in July 2013 to evaluate progress concluded that results were economically insufficient. On August 15, 2013, Correa scrapped the plan. Only $336 million had been pledged across the six-year effort, he said, and of that only $13.3 million had actually been delivered. The world has failed us, Correa said at his announcement, and he called the wealthy countries hypocrites who emitted most of the world's greenhouse gases while expecting poor nations to sacrifice economic development for the environment. He liquidated the Yasuni-ITT trust fund by executive order. Vice President Jorge Glas led reporters around the drilling site, which would be managed by the state oil company Petroecuador. By July 2016, the block was estimated to hold 1.7 billion barrels.

Ecuadorian law allows a national referendum if a campaign can collect signatures from 5 percent of the electorate. In October 2013, just after Correa opened ITT to drilling, an organization called YASunidos started gathering signatures. By 2014 they had more than enough, but the National Electoral Council threw out hundreds of thousands, claiming duplicates and fakes. YASunidos alleged foul play, including plagiarism of their campaign materials and one reported abduction and assault of an activist by government officials. The campaign did not die. Indigenous communities kept demanding the referendum for another nine years. In May 2023, the Constitutional Court finally validated the petition. The question put to voters was direct: Do you agree that the government of Ecuador should leave the crude of ITT, known as Block 43, below ground indefinitely? In August 2023, the referendum passed. The state oil company was ordered to dismantle its drilling operations in the Amazon within one year. President Guillermo Lasso, who had campaigned for drilling, was handed a defeat.

The Waorani people have lived in the Yasuni rainforest for centuries. Royal Dutch Shell workers entered their territory in 1930, followed by missionaries, which separated what remained of the original Waorani community. The Tagaeri and Taromenane are the descendants of those who withdrew completely. The Ecuadorian state, like colonial governments before it, leaned on the doctrine of terra nullius, the racist legal fiction that territories inhabited by indigenous people were empty of anyone with political rights, to justify claiming land and issuing oil concessions. Oil roads cut into the forest in the 1960s. The Waorani responded by organizing. They formed ONHAE, the Organization of Waorani Nationalities of Ecuador. They learned international law, traveled to the United States, met with oil executives and government officials, sued companies like Texaco, and, by the 1990s, changed the political calculus enough that oil companies had to acknowledge them. In 2007, they pushed the government to prohibit oil, gas, and logging in a 7,580-square-kilometer Waorani zone called the Zona Intangible. The 2023 referendum was the result of two decades of that organizing, carried finally across the finish line by voters in the cities and towns of Ecuador who heard the argument and agreed.