INVESTIGATION OF LONG TERM SAFE STORAGE OF CARBON DIOXIDE IN DEEP COAL SEAMS WITH ENHANCED METHANE RECOVERY RANATHUNGAASHANI SAVINDA 2017 Carbon dioxide storage in deep coal seams is known as one of the promising methods to mitigate global warming. This method enhances the production of coal-bed methane, which is a greener energy source. However, this CO2 storage causes significant alterations in the coal chemico-physical structure, producing modifications to its hydro-mechanical properties. This results in a reduction of CO2 injectivity and methane production. Therefore, the aim of this thesis was to identify ideal injection strategies to find the optimum conditions to harvest methane from deep coal seams while storing maximum amounts of CO2 by conducting comprehensive multi-scale experimental and numerical studies.