The atmospheric concentrations of greenhouse gases, such as carbon dioxide, methane, and nitrous oxide have a significant increase in the past 150 years. Especially, atmo- spheric concentration of carbon dioxide has increased to unprecedented level by 40% since pre-industrial times. Carbon dioxide forces the Earth’s energy budget out of balance by absorbing thermal infrared energy (heat) radiated by the surface, causing the ocean’s surface to warm, and melting more and more polar icecaps. Since polar icecaps help to regulate the Earth climate system, the fate of the Arctic icecaps is critical to the future climate. In the thesis, I construct some simple math models to predict how soon until the Arctic Ocean will be icefree. In the comparison with the comprehensive prediction processes from the IPCC, this thesis considers much fewer components and simpler math models to analyse the trend of the Arctic icecap. The prediction results in the thesis is approximately year 2035, which is the time of the Arctic Ocean will become icefree in September. This result could be regarded as a possible caution to alert people about the climate crisis.