A bipartisan group of US lawmakers has urged the Trump administration to oppose Colombia’s plan to revive aerial coca spraying in the Amazon. Their letter, reported by the Associated Press in late October, asks Washington to withhold backing for any return to the glyphosate-based fumigation programme that Colombia suspended years ago. The lawmakers warn that the tactic threatens rainforest biodiversity and the health of people living beneath the flight paths.
Colombia halted aerial spraying of coca crops after sustained evidence of harm. Herbicide drift contaminated food plots, waterways and pasture in rural and indigenous territories. Health researchers linked exposure to skin and respiratory complaints among residents near sprayed fields. Officials are now weighing a return to the method as coca cultivation climbs in remote growing zones. Manual eradication teams and crop-substitution schemes have struggled to keep pace with the new planting.
The lawmakers argue that reviving aerial spraying over the Colombian Amazon risks undoing years of conservation progress. The region holds some of the country’s richest biodiversity and anchors carbon storage for the wider river basin. They also point to the exposure faced by indigenous and campesino communities who farm and fish in the same watersheds targeted for fumigation, and who have had little say in past spraying decisions.
A programme Colombia already abandoned
Colombia’s aerial fumigation campaign ran for more than two decades before a court-ordered suspension ended it. Judges acted on findings that glyphosate, the herbicide used, posed risks to human health and ecosystems well beyond the coca plants it targeted. Communities living near sprayed areas reported losses of legal food crops planted alongside coca, which deepened food insecurity in already marginal farming regions. In its place, the government turned to manual eradication teams and voluntary crop-substitution agreements. Both approaches rely on a level of security access that remains patchy across parts of the Amazon basin.
Coca cultivation has expanded in several Amazon-adjacent departments in recent years. The growth is driven partly by weak returns from legal crops and by conflict dynamics that limit the state’s presence in rural areas. That expansion has renewed domestic pressure on Bogotá to find a faster eradication tool, even as it weighs the diplomatic and environmental cost of reopening a programme it once abandoned. The US lawmakers’ letter adds an external voice to that debate. It frames the decision as one with consequences well beyond Colombia’s borders.
Aerial spraying has long sat at the centre of the US-Colombia counter-narcotics relationship. Washington has historically funded chemical eradication and, more recently, manual and substitution-based alternatives. The lawmakers’ letter suggests that funding relationship could become a point of friction if Bogotá moves ahead with fumigation. Continued US support for anti-narcotics work in Colombia has often come with conditions tied to human rights and environmental safeguards.
What a reversal would mean for farmers
For the Amazon’s food systems, the stakes extend past the coca fields themselves. Smallholder farmers in spraying zones have long reported damage to cassava, maize and plantain plots grown beside coca as subsistence crops. Any return to aerial fumigation would test whether applicators can avoid repeating that pattern. The outcome of the current review will shape Colombia’s drug policy, and with it food security and land use across some of the Amazon’s most biologically significant departments.
Colombia’s government has not announced a final decision on whether to resume spraying. The review comes as the country balances domestic security demands against the diplomatic cost of straining ties with Washington over an issue with environmental consequences far beyond its own borders. For now, the debate leaves farmers in coca-growing departments uncertain whether next season brings more manual eradication teams, more substitution contracts, or a return of the planes that sprayed their fields in the past.
