Carbon dioxide (CO2) has been stated as one of major contributor to climate change and affects marine ecosystems. Among other CO2 capturing technology, adsorption is widely used due to its numerous advantages. Rubber seed shell (RSS), an agriculture waste from rubber plantation was used as precursor for preparing activated carbon (AC) by chemical activation using Malic acid as activating agent for CO2 adsorption. In this research, the AC was characterized and analysed by SEM, Micrometric ASAP 2020, TGA and FTIR instruments. The optimum condition was found at activation temperature of 600 °C, sample A. Results from specific surface and porosity analyzer shows the AC total pore volume, specific surface area and diameter were 0.2635 cm3/g, 480.5692 m2/g and 2.1937 nm, respectively. The CO2 adsorption studies showed the CO2 uptake for the AC was 2.26 mmol/gwhich is better most agricultural wastes' and commercial AC. It was found that malic acid helps to prolong the thermal stability of AC. The presence of a new FTIR peak in samples indicated N-H stretching and C=N stretching might due to remaining malic acid on the surface which increased the CO2 affinity and was an attractive source for CO2 adsorption applications. © Published under licence by IOP Publishing Ltd.