Devastating floods and landslides triggered by Tropical Cyclone Senyar on Indonesia's Sumatra Island have drawn attention to broader environmental issues, with experts saying the scale of destruction is linked to long-term deforestation, highlighting the need to halt further forest loss.

The National Disaster Management Agency said on Tuesday that the death toll in Aceh, North Sumatra, and West Sumatra provinces has risen to 962, with about 5,000 people injured and more than 1 million displaced. Senior officials estimate the island will need 51.82 trillion rupiah ($3.1 billion) for reconstruction and recovery.

However, environmentalists said the disaster has raised the urgency of a more fundamental challenge: arresting deforestation.

"Sumatra has experienced extensive primary forest loss over the past two decades," said Benita Nathania, senior lead for forest and landscape monitoring at World Resources Institute Indonesia.

Aceh and West Sumatra lost more than 320,000 hectares of primary forest, while North Sumatra lost more than 390,000 hectares, according to Global Forest Watch.

This long-term forest loss, combined with worsening climate change, amplifies the severity of hydrometeorological disasters, Nathania said.

Indonesia has seen more frequent extreme rainfall events exceeding 300 millimeters per day in recent years, while warming oceans are increasing the likelihood of tropical cyclones forming near the archipelago, intensifying both rainfall and storm impacts, she said.

Leonard Simanjuntak, country director for Indonesia at Greenpeace, said the disaster in Sumatra was caused by a combination of unusually heavy rains, climate change and years of environmental neglect.

The situation was aggravated by the absence of an effective early warning system, he said.

"People are not aware of and do not understand about a disaster that can happen suddenly. They don't have time to prepare," Simanjuntak told China Daily.

Sisilia Nurmala Dewi, Indonesia team lead at environmental group 350.org, said in a statement that "human-induced climate change" is intensifying storms and deforestation, destroying people's capacity to cope with climate impacts. She urged global leaders to tackle climate change at its root cause — burning fossil fuels and forest clearing.

Nathania said preventing future disasters requires both immediate and systemic measures, from risk-based spatial planning and watershed management to green infrastructure and nature-based solutions, alongside strengthening social systems and community capacity.

She also called for robust law enforcement and governance to address illegal forest clearing and for the reinforcement of moratoriums on new forest conversion permits.

Leonardus Jegho is a freelance journalist for China Daily.

Contact the writers at prime@chinadailyapac.com