Earth Simulator was proposed in 1997 as a way to predict climate change on a global scale. The performance level required to realize it was absurd – 1,000 times higher than that of other supercomputers at the time. But NEC employed 1,000 people cumulatively and utilized the full technological power of the NEC Group to achieve targeted performance. Earth Simulator began operation in March 2002 as initially planned. It was the clear winner in the TOP500 supercomputer performance ranking in June 2002 and stayed on top for two and a half years.