Both wind and solar power grew dramatically worldwide in 2012. The Global Wind Energy Council says that China, the USA, and other countries added significant wind capacity last year, bringing the total up roughly 20 percent from where it was in 2011 to about 282 gigawatts. The growth in US wind farms was, in part, spurred by tax credits; though the credit was renewed for 2013, construction isn't likely to continue at this pace. Europe, meanwhile, has the highest total level of wind energy, with Germany and Spain making up a significant portion and the UK leading in offshore wind farms.

Though solar produces barely a third as much energy as wind power, it grew more rapidly. The European Photovoltaic Industry Association has tentatively reported that global solar energy capacity passed 100 GW for the first time after seeing 30 GW added in 2012. Much of that is concentrated in Europe, particularly Germany and France, but the EPIA said countries like China were also becoming more significant markets: growth actually slowed in Europe and increased in the rest of the world. Overall, there was barely 40 GW of solar power worldwide at the end of 2010, meaning it's more than doubled in two years.

It's important to note that despite this growth, both wind and solar make up a relatively small percentage of overall energy. Wind power in the US, for example, is about six percent of our total output. And despite attempts to scale it down, coal energy remains a juggernaut. In 2011, the US Energy Information Administration reported a capacity of 318 GW from coal in the US, and it estimated that China — the world's largest user of coal — had over 650 GW of capacity that same year. Overall, global coal-fired capacity was said to be around 1,600 GW, dwarfing wind and solar put together. And while countries like China have been leading proponents of renewable energy (including other methods like hydropower), growing power requirements often lead to an increase in fossil fuel use as well.