50 years from now it will be 2064.
In the year 2050, it is estimated, even with decreasing population change rates, we will have added to the planet from 2010 to 2050 the combined 2010 populations of India and China, which we will have done because the population change rate, even though decreasing somewhat, never reaches a negative number, according to estimates of likely scenarios.
So, by 2064, we will again have added roughly the 2050 population of India to the planet, because people just can't stop f***ing around when they're impoverished and bored.
Thus, clearly, the fuel of choice in 2064 will be human waste.
Is that what was meant by "biomass" in the poll?