Con to the question "Can Alternative Energy Effectively Replace Fossil Fuels?"
"Oil provides 95% of the fuel demands of the transportation sector... Every transport mode – cars, trucks, trains, buses, marine vessels, and aircraft – relies almost entirely on petroleum fuels. Only natural gas liquids and, in recent years as the result of regulated fuel mandates, ethanol - have made small inroads in the dominant share held by oil. Further, on the basis of the projections by all major agencies that analyze energy supply and demand trends to 2035 and 2040, this will continue to be the case for the foreseeable future...
Proponents of the all-renewable future seem to be stuck in a time warp. For them, it is still 2014, oil prices are still close to $130 per barrel, and natural gas and coal prices are surging. In such a world, it may be easier to make the case that renewables will become far more competitive sooner. The reality, of course, is that the decline of international oil prices to the range of $40 per barrel and the dramatic slumps in natural gas and coal prices in many areas (especially North America), has meant that these hydrocarbons are far better placed to compete with alternative energy sources."
"Why Renewable Energy Cannot Replace Fossil Fuels by 2050," friendsofsciencecalgary.wordpress.com, May 2016