Corrosion is estimated to cost $2.5 trillion dollars annually, of which ~$500 billion could be saved by the application of existing technologies.  But for the remaining $2 trillion, a large portion of that is due to a lack of understanding of the underlying mechanisms of corrosion, which would provide guidance to mitigation technologies.  And this corrosion problem is likely to increase as several carbon reducing technologies involve environments which are conducive to the corrosion of metal infrastructure.  This is especially true of carbon capture and sequestration, where the transport of CO2 from its capture point to its sequestration point involves the interaction of metal and supercritical CO2, which can produce corrosive environments when impurities such as water occur.  NIST-Boulder currently has the only supercritical CO2 corrosion facility in the country.  Important corrosion data will inform new standards on CO2 pipelines (materials and operating conditions) being developed for carbon sequestration.  And advanced characterization will reveal details of the mechanism of corrosion, allowing better corrosion prevention technologies in the future.