Reducing non-renewable energy and resource use, reducing waste and pollutants, and reversing land degradation and biodiversity losses would then seem key to greening the economy. Technologies will need to undergo drastic changes so as to become more efficient in the use of energy and other resources and minimize the generation of harmful pollutants. Available from http:// sites.goog le.com/site/ econgeodata/maddison-data-on-population-gdp. According to the more cautious scenario, for CO, equivalent concentrations to be stabilized at 450 parts per million (consistent with the target of stabilizing global warming at a 2° C temperature increase from pre-industrial levels), the use of fossil fuels would need to drop by 80 per cent by mid-century.