The Calculator has its origins in the UK in 2009, when the Government's Department of Energy and Climate Change (now BEIS) was looking for a solution to meet the world's first legally binding emissions target – an 80% reduction by 2050 based on a 1990 baseline. Because there was uncertainty about what technologies would be available in the future, the team decided to build a new tool to explore all the options available, rather than using existing models that determine an optimum pathway.

Key messages from the Calculator were published as lessons learnt from all pathways that meet the 2050 target. The messages were then used to develop the Government’s overall emission reduction strategy in 2011. The simplified, My2050 Calculator, was created for use by the general public. Over 17,000 people have submitted pathways using the site, providing a unique insight into public opinion on the energy transition.

Other countries, regions and territories have since adopted a similar approach and have built their own Calculators to help inform policy and increase public understanding of energy issues. The Belgian region of Wallonia was the first, quickly followed by China. In 2012, the UK Government received funding from the International Climate Fund to support 10 developing countries to build Calculators using locally-based teams.

Each team has refined and extended the Calculator methodology to answer their own specific issues. We hope that further places continue to benefit from the Calculator in future.