Thick haze blotting out the sun in Singapore and Malaysia is an early warning sign that one of the world’s more ambitious attempts to bend commodity markets to political and environmental imperatives is failing.

The smoke comes from thousands of wildfires burning on the islands of Borneo and Sumatra. The causes of such blazes can be complex, but clearing forest to make way for palm oil has long been rampant in Southeast Asia. A combination of climatic, economic and political circumstances right now in Indonesia, the biggest producer, make conditions unusually favorable for a devastating season. For the European Union, which has struggled for years to stamp out unsustainable palm cultivation, that will represent a humiliating setback.

There’s already circumstantial evidence that plantations will spread as a result of the recent fire weather. NASA satellite imagery recorded last week shows extensive burns around the city of Banjarbaru in South Kalimantan province on Borneo in areas where native forest abuts stands of oil palm. Claims of progress in halting Indonesian deforestation over the past decade may simply be the result of a run of wet years that made it harder to burn off native vegetation.

That situation has reversed this year. Hot, dry weather has spread across Southeast Asia in recent months thanks to the confluence of El Niño and a positive Indian Ocean Dipole, two oceanic climate cycles that parch the region. In such circumstances, even fires started accidentally can build into damaging conflagrations.