Market penetration of primary energy and its role in the Greenhouse warming problem

Abstract

When introduced some 10 years ago, Marchetti's claim for a 50–100 year irreducible penetration time for primary world energy forms legitimized serious consideration of the longterm climatic effect of fossil-fuel released carbon dioxide as a major global environmental concern. Since this time, although the truth or falseness of Marchetti's thesis has not been established, major changes in our perception of the nature of the problem have ensued. We discuss both the effect of the reduction in projected fossil-fuel energy-use rates and the climatic warming effects of trace-gas species in addition to CO 2, and we conclude that, even though most of today's energy projections imply a greatly reduced rate of global warming from future CO 2 emissions, projections of currently observed growth rates in the other greenhouse gases result in a net heating of the earth at a rate and of a magnitude comparable to that estimated in the mid-1970s when serious climatic impacts were thought to be possible within a 50-year period. Redeployment of world energy use from its current fossil-fuel base to renewable forms in order to avoid this environmental problem therefore faces the same critical timing difficulty it did a decade ago.