This implies an improvement in eco-efficiency by a factor of 3.2, which is almost as ambitious as the “factor 4” goal of doubling wealth and halving resource use, originally suggested by von Weizsacker, Lovins and Lovins (1998). Thus, even world average levels of energy use of less than 70 GJ per capita would be achievable by mid-century, in line with the target suggested by the present Survey (see below). Thus far, however, these international efforts have had a relatively small effect on the global energy transition.