The most obvious use of high performance computing in sustainability is in understanding the complex climactic systems of this planet. Whether man made or natural the climactic shifts of the planet affect us all socially and economically. Understanding and planning for these shifts with accurate climate modeling is an important endeavor. Our modern society depends on energy and many of our current forms of production pollute our environment. High Performance Computing is being used to improve old energy production methods such as clean coal production and developing new and sustainable production methods such as nuclear fusion. The use of computational power is also a critical to future national competitiveness however with the growth of large data and compute centers there is significant value to be gained from new data centers designed from the ground up with energy efficiency and sustainability.