Environmentally friendly compared to other modes of transport, is still responsi­ble for 1 billionns of CO2 emissions per year and 2.7% of total global emissions, although it has the lowest CO2 emissions per mile. In order to keep the world's sur­face temperature below the critical +2 °C, International Maritime Organization works with alternative methods especially in the energy efficiency design index, to increase the productivity depending on the type and operation of the ship to reduce current CO2 emissions each tonne per mile basis. More energy-efficient vessels are necessary due to the increasing volume of maritime trade in parallel to meet the growing energy demands and reduce total CO2 emissions. Measures to reduce CO2 emissions also increase efficiency and fuel-savings. The most significant parameter of fuel economy is the speed of the ship. Sensitivity analysis was used to determine the ecological speed limits of vessels in terms of minimum commercial profitability by a gradual reduction in operating speeds. Consequently a solution methodology for the effects of slow steaming to the global environment is presented as a CO2 emission reduction activity under the systematic analysis of human thought.