ONE thing that grabbed my attention during our recent trip to National Science Centre in early January was a map (see figure) that illustrated the expected sea level rise by 2100 projected by National Hydraulic Research Institute (Nahrim).
It shows that for Malaysia, the east coast of Sabah – from Kudat to Tawau – will be the area that experiences the highest sea level rise, ranging between 0.4 to 1.1 metres with an average of about 0.5 metres. Especially, the south-eastern area bordering North Kalimantan has some of the darkest red dots.
Three weeks later, I was in Tawau. The city is surrounded by the Sulu Sea to the east and the Celebes Sea to the south. Established in the 1890s by the British, it was destroyed during World War 2 but was later rebuilt. According to the Census 2020 report, the urban area is now home to nearly 290,000 inhabitants. However, outside the city, the population is relatively small with only about 84,000 people scattered throughout the district.
Most areas in the district are planted with oil palm, except the city and the Tawau Hills Park. As a border district, Tawau serves as the gateway to Kalimantan, with international ferry services connecting it to Nunukan of North Kalimantan.
The downtown area facing Cowie Bay may be particularly vulnerable to the rise in sea level. Physical infrastructure such as buildings, ports, roads, sewage discharge facilities, power lines, and others could suffer damage from seawater intrusion or even be inundated.
The coastal region is also home to many Tawau residents, with numerous ‘water villages’ consisting of houses built on seawater lining up from east to west. These residents are among the most affected if the water level continues to increase. By the end of the century, large swaths of low-lying land could also be engulfed by the sea.
The effects of sea-level rise resulting from climate change are not limited to artificial borders and are expected to impact the Indonesian counterparts as well. From Tawau to Nunukan, large tracts of mangrove forests can be found along the coast. Coastal erosion due to the changes in currents and waves will bring devastating impacts on coastal ecosystems. In addition to physical alterations, salt contamination of freshwater aquifers by seawater intrusions may also greatly damage flora and fauna, destroying habitats for both lives on land and below water. Changes in soil and water properties can be harmful to agriculture, causing cropland degradation and reducing productivity.
However, the threat of climate change to Borneo can be insidious. Unlike its northern neighbour, i.e., the Philippines, Borneo is fortunate to stay outside the general range of cyclones. However, the increasing frequency and severity of flood events across the island have reminded people about the potential impacts of climate change and sea level rise. There were numerous reports of flash floods across Borneo in 2022, with unusually heavy rainfalls cited as a main cause.
To make things worse, land cover changes considerably exacerbate the flood risks. By mapping flood events across Kalimantan, a group of researchers, J. A. Wells and the team in their paper published in 2016 found that flood frequency was associated with land use activities like logging and mining. In contrast, the villages in more forested watersheds were found to have a lesser flood risk.
Things can also go the other way – droughts and fires. Droughts in Borneo have become more intense in the past decades. The uncontrolled fire events were made worse, becoming much larger and longer due to El Niño-Southern Oscillation. The most recent massive fire event occurred in 2015, mainly in Central Kalimantan, causing enormous economic loss up to billions of US dollars.
In the event of a worst-case scenario, the inhabitants of the central area of Borneo may need to brace themselves for a temperature increase of approximately 4 degrees Celsius by the conclusion of the 21st century. This elevated temperature could have severe consequences for public health, including heat waves that may endanger vulnerable populations such as the elderly and young children. Additionally, the risk of fire could be exacerbated by the rise in temperature.
Several solutions have been proposed to combat climate change. Some coastal cities have opted for adaptation measures, such as constructing seawalls, re-planning roads, and planting mangroves, in order to enhance their resilience to environmental changes.
Meanwhile, countries have implemented a variety of energy and industrial policies to mitigate climate change and reduce emissions. However, many of these approaches face challenges due to their high costs and people’s reluctance to alter their lifestyles and behaviors.
One potential area where Borneo can make a significant contribution is by reducing and preventing greenhouse gas emissions through its abundant natural capital.
Borneo plays a major role in global emission dynamics due to its substantial terrestrial carbon stocks. Proper and sustainable management of land use activities, particularly agricultural expansion and mining, will be an immediate priority for Borneo in tackling climate change.
The urgency of the climate crisis presents an opportunity to bring together various stakeholders to achieve a sustainable transformation of Borneo’s economy, which is currently heavily reliant on primary resource extraction. However, attaining this objective requires clear and concise vision from decision-makers.
“We will certainly find solutions to these problems.” I was surprised by my 7-year-old’s optimism.
“How?” My big ask.
“Don’t know, but we will when we run the world.”
While the early 21st century was marked by great innovation and exciting developments, it was also a time of global chaos and widespread anxiety. As I stared out of my hotel room window, the disturbing scenes from Netflix shows – destruction, pollution, and conflict – flashed through my mind.
I hope that the world we leave behind for the next generation is not too bleak.
Dr Goh Chun Sheng is a researcher at Sunway University and Harvard University. He is interested in exploring sustainable development in both Malaysian and Indonesian Borneo.