40 years of Energy Efficiency in California: The Rosenfeld Effect, a prelude to Climate Change Policies

'Degrowth made perfect'. That, in a nutshell, is California's energy policy. Now known as the 'Rosenfeld Effect', it was developed and implemented with great success as part of the first Energy Transition (TE1), and its outcome largely anticipated some of the recommendations of the Paris Agreement (COP 21 Paris December 2015). Following a long and difficult gestation period, notably after the KYOTO Agreement (1997), the latter formalized the renewal of the second Energy Transition (TE2). In contrast to the first, the immense consequence of a conflict in the Middle East in the autumn of 1973, this TE2 was more than hoped for by a large majority of the planet's citizens. It did, however, have one thing in common with its predecessor: the upheaval of energy policies almost everywhere in the world, confirming de facto the priority of Energy Supply strategies. During the last quarter of the 20. century, however, Energy Demand was a major option in California and Sweden, while Energy Savings played a more modest role in improving energy intensity in other countries. This notable Californian exception arose from the determination of Prof. Arthur H. Rosenfeld, a renowned physicist at the LBL (UC-Berkeley), to tackle the challenge of the embargo through a global analysis, tackling head-on the technical, economic and political issues involved. This R and D program, which was almost instantly invented, quickly gave rise to a very proactive policy in the Golden State, the result of which, 40 years later, is a triple win in terms of energy consumption (33% lower than the US average), a corresponding reduction in financial costs and a lower environmental impact. A truly paradoxical synergy in a country where economic dirigisme is, at best, a heresy. However, the success, context and implementation summarized here, make us strongly hope that Energy Efficiency will become the mainstay of Climate Change Policies