The future temperature is projected using different models with different scenarios (RCP 4.5, RCP 8.5 etc.). These models show variability in projected temperature. There is an excel file attached that has model temperature output of 10 different models with RCP4.5 scenario from 1800-2100 (monthly values). The file also contains HadCRUT observed temperature data. Using the given data set (PS1_2019_data.xlsx): i. For the years 1861-1978, generate a model-ensemble mean temperature trend. Is the trend significantly different from that of HadCRUT observations? ii. Do hot temperature extremes occur at similar likelihoods in the model ensemble and observational datasets? iii. For the year 2030, what is the likelihood of modelled global mean temperature exceeding 280 K, 289 K? iv. One of the aims of COP21 is to keep the global temperature rise well below 2oC, in 2100, above preindustrial levels. The 1861-1900 average temperature, can be used as pre-industrial level temperature. Comment on the feasibility of this goal and provide your reasoning behind the comment