This paper presents the energy demand projection for Malawi considering implementation of two energy development strategies. The strategies are Malawi Biomass Energy Strategy (BEST) and Malawi electricity investment plan. Long-range Energy Alternatives Planning System (LEAP) software was used as the simulation tool. Environmental effects of the energy sector towards global warming by the energy sector as a result of implementing the strategies have been investigated. Three scenarios were developed, the first one to reflect on business as usual, the second one depicting implementation of Malawi BEST and the third one depicting implementation of the Malawi Electricity Investment Plan. A fourth scenario was developed to depict implementation of both strategies. 2008 was used as the base year with energy mix of consisting of biomass consumption decrease in all the scenarios due to better efficiency in the utilization of biomass and change in life style by people as a direct response to available energy alternatives. Implementing both the Malawi BEST and Malawi Electricity Investment Plan for energy sector development would be better in terms of both energy supply and global warming effects.