JAKARTA, Indonesia — Nearly 2,000 wildfires are burning across Indonesia, turning the sky blood red over central Sumatra and creating dense clouds of smoke that have caused respiratory problems for nearly a million people.
Dense white smoke filled the air across Sumatra and Indonesian Borneo, known as Kalimantan, the two areas that were hardest hit. Many of the fires were set deliberately to clear land for plantations that produce palm oil and wood pulp for making paper, the authorities said.
The blazes, which tore through sensitive rain forests where dozens of endangered species live, have drawn comparisons to the wildfires in the Amazon basin that have destroyed more than 2 million acres.
By Wednesday, rain had brought some relief in reducing the number of Indonesian hot spots, which include burning jungles and smoldering peatfields, to fewer than 1,800. The count was more than 3,300 two days earlier.
Towering flames devoured trees and brush in what was once dense jungle, leaving behind a blackened wasteland of charred stumps and bushes.
The fires are an annual phenomenon as large plantations and small farmers use the age-old slash-and-burn method during the dry season to open new land for planting.
Neighboring Singapore and Malaysia have complained for decades about the smoke that drifts over from Sumatra and Kalimantan and chokes the region every year at this time.
This year’s fires are the worst in Indonesia since 2015. Officials estimate that the fires have burned more than 800,000 acres.
The smoke and flames threaten three species of endangered orangutans that are found only on Sumatra and Borneo.
Even though the fires are predictable, Indonesia is woefully unprepared to combat the blazes, which often start in remote and inaccessible areas.
Slash-and-burn farming, employed for thousands of years in the region, is illegal in Indonesia, but few people are ever prosecuted.
The environmental group Greenpeace criticized the government on Tuesday for not taking action against those companies that set fires to clear land for planting.
In a report analyzing the fires of the last four years, the group said that none of the 10 companies with the largest areas of burned land faced serious civil or administrative sanctions and that no palm oil company had lost its license. This year’s fires are occurring in many of the same areas as in past years, the group said.
Greenpeace urged Indonesia’s president, Joko Widodo, to strip companies of their licenses immediately if there are fires burning on their land.
“Stopping this recurring fire crisis should have been at the top of the government’s agenda since 2015,” said Kiki Taufik, the global head of Greenpeace Indonesia’s forests campaign. “But our findings show the reality: empty words and weak and inconsistent law enforcement against companies.”
Officials said that 14 companies are under investigation for allowing the fires to spread on their land and that more than 300 people have been identified as suspects.
The sky turned deep red last week and over the weekend in the central Sumatran province of Jambi. Pictures and videos of the eerie scene were circulated widely on social media.
Some described it as “hellish.”
The red color was caused by “mie scattering,” officials said, a phenomenon in which the sun shines on a large number of microscopic smoke particles, which match the wavelength for the color red.
“This is not Mars. This is Jambi,” wrote the Twitter user Zuni Shofi Yatun Nisa, who posted a video showing the red sky over her province. “We humans need clean air, not smoke.”
Respiratory problems have affected 920,000 people in the six provinces in Sumatra and Kalimantan where the fires have been the worst, according to the disaster management agency.
Most affected are the young, the elderly and the sick.
One civil society group, the Muhammadiyah Disaster Management Center, operates two cars in Kalimantan that bring oxygen to people in the fire zone who are unable to leave or cannot afford to evacuate.
“This is where we have a different approach with the government,” said the group’s vice secretary, Abdoel Malik. “The government tends to tell people to go to the local clinics for treatment” instead of the government “going to them.”
He said this was the fifth year that the organization had provided the oxygen service and that he was shocked by the magnitude of this year’s fires.
“No one expected that it would be this big,” he said. “All the humanitarian organizations are shocked. None of them were prepared for this.”