Recent NASA studies on the effects of climate change have been rather harrowing, highlighting the need for alternative energy sources. NASA climate scientist Dr. Drew Shindell stated that “it's more clear than ever that we need large, rapid emissions reductions to avoid the worst damages from climate change.”
Reducing our overall energy usage is obviously a big part of curtailing emissions. But renewable energy sources are also a key piece of the puzzle. So it is somewhat heartening to play watch this .GIF of wind-farm growth from the Department of Energy.
The map starts with one tiny wind farm in southern California in 1975. From there, wind farms continue to spread throughout California for the next two decades. Then in 1994 the first wind farm outside of California appears. From there, they quickly spread across 39 states by 2012 (the most recent statistics available). You can play with an interactive version of this map here.