El Nino, climate change supercharged Indonesia fires, study says

A strong El Nino and human-induced climate change fueled the hot and dry weather over Indonesia this year that sparked the country’s worst wildfire season in a decade, according to new research.

El Nino was the driver of the severe lack of rainfall, while climate change was the cause of high temperatures, a report by World Weather Attribution shows. Human-induced warming made hot and dry conditions about three times more likely, as well as more intense, researchers said.

Indonesia’s worst fire season in years cloaked local towns and neighboring countries such as Singapore and Malaysia in toxic smog, prompting schools to close, straining diplomatic ties and crimping palm oil output. Poor rainfall from June through the end of October left the landscape bone-dry, making blazes often linked to slash-and-burn agricultural practices harder to contain.

“El Nino turned off the taps, but fossil fuel emissions turned up the heat,” said Friederike Otto, a professor of climate science at Imperial College London and a co-author of the study published Friday. “Without rapidly transitioning away from fossil fuels and strengthened land-management protections, we will see more and much worse fire seasons like this in the future.”

Climate change amplified the hotter conditions from August to October, making the seasonal heat about 1.6 C hotter and more likely to occur, according to the study. Parts of Indonesia have also seen decades of deforestation and peatland draining, significantly increasing the fire risk, the authors wrote.

The ongoing El Nino is estimated to have reduced Indonesia’s seasonal rainfall by about 50% this year, and together with higher temperatures, the country experienced “record breaking fire weather,” the report said.

“Our analysis shows that climate change acts as a force multiplier during El Nino years,” said Theodore Keeping, an extreme weather and wildfire researcher at Imperial College London and lead author of the study. “When a strong El Nino hits, global warming makes the resulting fire weather significantly hotter, drier, and harder to contain.”