with significant economic loss. Since 1989, power companies in North America, the United Kingdom, Northern Europe, and elsewhere have invested in evaluating the GIC risk and in developing mitigation strategies. GIC risk can, to some extent, be reduced by capacitor blocking systems, maintenance schedule changes, additional on-demand generating capacity, and ultimately, load shedding. These options are expensive and sometimes impractical. The continued growth of high voltage power networks results in higher risk. This is partly due to the increase in the interconnectedness at higher voltages, connections in terms of power transmission to grids in the auroral zone, and grids operating closer to capacity than in the past. To understand the flow of GIC in power grids and to advise on GIC risk, analysis of the quasi-DC properties of the grid is necessary. This must be coupled with a geophysical model of the Earth that provides the driving surface electric field, determined by combining time-varying ionospheric source fields and a conductivity model of the Earth. Such analyses have been performed for North America, the UK and in Northern Europe. The complexity of power grids, the source ionospheric current systems and the 3D ground conductivity make an accurate analysis difficult. By being able to analyze major storms and their consequences we can build a picture of the weak spots in a transmission system and run hypothetical event scenarios. Grid management is also aided by space weather forecasts of major geomagnetic storms. This allows for mitigation strategies to be implemented. Solar observations provide a one- to three-day warning of an Earthbound coronal mass ejection (CME), depending on CME speed. Following this, detection of the solar wind shock that precedes the CME in the solar wind, by spacecraft at the Lagrangian point, gives a definite 20 to 60 minutes warning of a geomagnetic storm (again depending on local solar wind speed). It takes approximately two to three days after a CME launches from the Sun for a geomagnetic storm to reach Earth and to affect the Earth's geomagnetic field. GIC hazard in pipelines Major pipeline networks exist at all latitudes and many systems are on a continental scale. Pipeline networks are constructed from steel to contain high-pressure liquid or gas and have corrosion resistant coatings. Damage to the pipeline coating can result in the steel being exposed to the soil or water possibly causing localised corrosion. If the pipeline is buried, cathodic protection is