The US energy consumption rate for 2011 is available in existing public  data [bp.com/statisticalreview] "BP Statistical Review of World Energy."  Assuming a 2% growth rate per year, find the doubling time [yrs] and  estimate the energy consumption rate [MTOE] in the year 2050. Also,  assuming that current US coal reserves supplied all the fuel energy for  the US, estimate how long the coal would last [yrs].