Remember when cattle ranching was the biggest threat to the Amazon rainforest? Now add the relentless quest for oil. The Ecuadorian government is currently planning to sell an enormous area of pristine rainforest to oil companies.

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Ever since I can remember being aware of the Amazon rainforest, my understanding was that big corporations were steadily razing it to make way for cows raised for beef. While illegal cattle ranching continues to be a major threat, oil interests have been hard to keep at bay.

The government in Ecuador made a pitch to Chinese oil companies in Beijing last week as part of an effort to auction off more than three million hectares — that’s more than 11,500 square miles — of Amazonian rainforest. The meeting was the fourth leg of a roadshow to publicize the bidding process. Ecuador’s ambassador to China called the prospective relationship a “win-win,” Jonathan Kaiman reported in the Guardian.

Ecuadorian officials say the oil blocks on offer will be developed under “strict sustainability guidelines,” but opposition groups can already imagine the devastation. Saying no may not be so easy, though. Ecuador owes China nearly $9 billion worth of oil in exchange for past cash loans per the CIA World Factbook.

What’s the worst that could happen? Peruvians have a cautionary tale. The government there just declared an environmental emergency in a remote area of the Amazon that’s home to one of the country’s largest oil fields. In 2001, the Argentinian oil company Pluspetrol took over drilling operations from Occidental Petroleum.

A combination of factors, including lax regulations, led to contamination in the Pastaza river basin near the border with Ecuador. High levels of barium, lead, chrome and petroleum-related compounds have been found in the soil and are poisoning the people who live there, according to the Guardian’s Dan Collyns. Pluspetrol has 90 days to clean it up.

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Back in Ecuador, environmental and indigenous groups are fighting the proposed sale. The nonprofit Amazon Watch says that Chinese participation in the auctions would violate green credit guidelines and international law. Even if the groups succeed in blocking the auction, the country’s financial woes won’t go away quickly. Someone will end up paying, and the price may be extremely high.

Photo: Crude oil from a pit that Chevron, formerly Texaco, abandoned in the Ecuadorean Amazon rainforest in 2010. Credit: Caroline Bennett, Rainforest Action Network.