Vulnerability assessment shows Brunei Darussalam has medium to high climate change exposure. Natural disasters in the country such as flash floods, landslides, and forest fires are then compounded by the increasing trends of rainfall and temperature changes. Climate change will undoubtedly exacerbate these natural disasters.

According to Brunei Darussalam Meteorological Department (BDMD), the trend of mean temperature increases at a rate of 0.25°C per decade. The highest maximum temperature recorded in Brunei Darussalam is 38°C (28th March 1983). During El-Nino events such as in year 1997-1998 and 2015-2016, Brunei Darussalam has encountered several bush and forest fires which causes severe haze conditions.

It was recorded that Brunei Darussalam received 275mm total daily rainfall on 30th September 2019, which broke the country’s highest daily rainfall record. Although the sum of total rainfall in 2019 was considered normal, there is evidence of irregularity in the monthly rainfall trends.

Based on BDMD studies, without climate action taken into account, Brunei Darussalam is projected to have an increase of about 4°C by year 2100 (RCP 8.5 scenario) and our rainfall pattern shows an intensifying trend in the total rainfall amount, increasing at a rate of 100mm per decade. BDMD has estimated the projection of rainfall will increase at a rate of 10.8mm per year (under RCP 8.5 scenario) from 2006-2099.

As the majority of our community resides near the coastline, we are unquestionably vulnerable to tidal erosion and inundation. When both high tides and rainfall simultaneously, there is a chance of an increase in Brunei’s water level. This will cause flooding especially on a low-lying area in the country. According to Sea Level Rise Task Force (SLRTF) analysis, Brunei Darussalam’s water level has increased about 5-5.5mm per year. Based on this, with a projection of sea level increase at the range of 0.44-0.45m by 2100.

Brunei Darussalam is known for its biodiversity and tropical rainforest; the government takes high priority in the protection of both marine and terrestrial habitats. The changes in weather patterns and trends will certainly affect the phenology of migration, pollination, and even the breeding season of our local wildlife. In addition, climate-induced disasters will potentially damage their habitat, which is correlated with the loss of key species populations such as the Proboscis Monkey and the Rhinoceros Hornbill.