Uncertainties in Prediction of Future Sea Level Rise Due to Impact of Climate Change

Abstract

On reviewing the development of the research methodologies on climate change and sea level rise during the last two decades, it is observed that the assumed scenarios for apprehending the rise in global temperature are grounded on a lot of uncertainties. The real-time data varies from IPCC’s predictions. The gradual transition on the emission pathway scenarios from SRES (2000) till RCPs in AR5 of IPCC depicts the conceptual difference between the two concepts in scenarios. SRES represented detailed socio-economic-based scenarios, but RCPs are based on the capacity of a gas affecting the change in energy in the atmosphere due to GHG emissions known as Radiative Forcing. Considering the possible range of the radiative forcing values in 2100, AR5 of IPCC considers the four RCPs numbered as 2.6,4.5, 6.0 and 8.5 as per greenhouse gas concentration trajectories (not emissions). The present condition of melting of ice sheets at Antarctica and Greenland is quite high and it is understood that such melting will continue. Even in a situation, if the anthropogenic emission of GHGs is immediately stopped, the self-sustained melting will continue. Models so far being based on numerical and probabilistic approaches are expected to undergo abrupt change because of the current inconsistent ice sheet dynamics. Considering deep uncertainty in socio-political and economic changes amongst nations, the importance of usability of model hierarchy for the complex science of climate change is becoming unforecastable, in the prevalent ice dynamics during accelerated warming situations. In reality, the predictions are becoming less reliable.  Possibility of the scenarios likely to be changed are apprehended during the advent of CMIP6 and the variations in contributing factors in the form of SSPs in the upcoming IPCC AR6, in 2022 and it is indicated that the research may take a new turn. A multidisciplinary approach to research with minimum uncertainty in a more precise and finer manner is the need of the day.