Go renewables, go!According to the International Energy Agency (IEA), by 2018 renewable should overtake natural gas to become the world's second-largest source of energy (oil is #1). Of course, no single source of renewable energy can beat gas on its own (yet), but if you combine solar, wind, hydro, geothermal, and biofuel/biomass, we can definitely get there if we maintain solid growth rates; the current projection sees a 40% growth in clean energy over the coming 5 years, which would bring the total to about 25% of total energy consumption, with hydro still accounting for the lion's share (17%).
In 2012, renewables grew 8% to 4,860TWh, as much as China's total electricity demand!
Of course, there's always a difference between what is projected and what happens, but this should just encourage us to make an even bigger effort. We should be able to beat that prediction and clean up the world's power grids much faster than anyone expect if only we get some political will into it and increase the number of smart energy investments.
Renewables tend to have bigger upfront costs, but once they are built, there is no fuel costs. And when we compare with dirty sources, we should take into accounts the huge costs of global warming and pollution (air, water, soil). Renewables are a bargain when things are measured properly.