As the energy system becomes more globalised and interconnected, gas security challenges are evolving. The current period of gas oversupply - driven by overcapacity in the LNG market - should not overshadow the critical importance of global gas security. Global Gas Security Review 2016, the first edition of a new annual series, examines the evolving global gas market structures and looks at the market's ability torespond to potential shocks. It shows that the current situation could lead to a false sense of comfort about gas security, which could evaporate quickly once market conditions change.The report also analyses how LNG markets responded to the Fukushima accident through case studies focusing on Japan and Europe. Both regions have fuelswitching potential but also face structural changes as coal and oil-fired capacity retires, affecting the gas market's flexibility to respond to overall shocks. Global Gas Security Review 2016 also addresses two critical forward-looking questions: how much redundancy is embedded in the LNG upstream and liquefaction chain, and how flexible is LNG production