Floods and the Climate Crisis in Indonesia

Floods encircle Indonesia's capital city, Jakarta. photo source: merdeka.com

In 2007, flooding in Jakarta killed 57 people and displaced over 420,000 residents. In 2013, flooding caused 47 deaths, and in 2020, caused another 66. Indonesia, Jakarta especially, has long been prone to flooding. It is the country’s most frequently occurring natural disaster, with the Indonesian National Agency for Disaster Management reporting 464 instances of flooding in Indonesia annually, and flooding accounting for 82% of the 749,000 disaster displacements recorded in Indonesia in 2021. However, in recent years, these floods have only become more intense and deadly, in large part due to the effects of climate change. 

Flooding has two primary causes: prolonged, heavy rainfall and loss of tree cover. Climate change and destructive human activity intensify both of these factors. 

Indonesia’s Meteorology, Climatology and Geophysics Agency classifies extreme rainfall as greater than 150 mm per day. In the 2020 floods, some areas of Jakarta recorded 377 mm of rainfall in a single day. This amount of rain is unprecedented and unnatural, even for the tropics, and a warming climate is to blame. When heat-trapping greenhouse gasses are released into the atmosphere, temperatures rise, which in turn increases water evaporation from oceans, soil, plants, etc. This means there is more water vapor in the atmosphere, and water vapor eventually becomes rain. When there is too much rain, soil can’t absorb it quickly enough, and the excess water causes flooding. This is exacerbated in cities like Jakarta, where much of the ground is covered by infrastructure like roads and sidewalks. 

Soil’s ability to retain water is also affected by trees. Trees provide organic matter that keeps soil porous and absorbent, while roots facilitate water absorption and bind and consolidate soil. This helps prevent erosion, which, when combined with flooding, causes another major (and life-threatening) natural disaster: landslides. Human activity, such as deforestation – including illegal logging – and more frequent forest fires are contributing to the loss of tree cover in Indonesia. For example, around the Barito River Basin in Borneo, satellite data from the National Institute of Aeronautics and Space of Indonesia shows that forest area – which includes watersheds – has decreased by more than 100,000 acres, while palm oil plantations and mines now cover over 200,000 acres. This means the Barito River Basin area has become particularly prone to flooding. Meanwhile, according to an analysis by Global Forest Watch, Cyclops Mountains in Papua lost 887 hectares of tree cover between 2001 and 2018, resulting in the flooding of Papua’s Waibu, Sentani and East Sentani districts. 

Reducing the frequency and intensity of flooding has substantial advantages. Most compellingly, it would save countless lives. As seen in Jakarta, flooding kills dozens of people, with the total death toll now well into the hundreds. In other regions of Indonesia, too, flooding has deadly consequences: recently, in 2021, 41 people in East Flores died after severe flash floods and landslides hit Flores Island. Floods also displace enormous numbers of people, often well into the hundreds of thousands. They destroy homes, including 97,000 in the 2013 Jakarta floods, and places of employment, dramatically disrupting lives and requiring large-scale, logistically complex rescue and restoration efforts. Then there is the economic impact to consider. Flooding causes extensive damage to infrastructure that is incredibly expensive to repair. The 2013 Jakarta floods, for example, caused $490 million USD in economic losses and damages, while the 2007 Jakarta floods caused nearly double that: $900 million USD, according to the World Bank. Amounts like these – especially when not accounted for in annual budgets – set back an emerging economy such as Indonesia’s, taking away resources that could otherwise be used for development. Unfortunately, the economic toll is only predicted to worsen; research estimates that Jakarta’s flood damage costs could increase by as much as 400% by 2050,  highlighting the urgency of addressing the issue.

Currently, Jakarta’s government is attempting to mitigate flooding by diverting water to East and West Jakarta via flood canals that empty into Jakarta Bay. This is in line with many of President Joko Widodo’s other flood-management policies, most of which entail building infrastructure such as sea dykes, dams, reservoirs, polders, canals, and water tunnels. However, these solutions are temporary and not always effective. The flood canals, for example, are fast becoming unfeasible due to heavier rainfall and garbage clogging the waterways. In fact, the situation in Jakarta is so untenable that it is one reason the government is building a new capital, Nusantara, in Borneo. This is the start of a potentially vicious cycle: if Nusantara also falls victim to the effects of climate change and natural disasters, will the government relocate the capital once again? A longer term, more sustainable — albeit also more complicated — solution would be to address the root of the problem, climate change compounded by harmful human activity, through large-scale, nation-wide legislation, policies, and programs. [Apprentice: Katriona, Princteon University)