This is a guest post by Stephen Sorrell, senior lecturer Science and Technology Policy Research, Sussex Energy Group, and lead author of the UKERC Global Oil Depletion report, and Christophe McGlade, doctoral researcher at the UCL Energy Institute. This post was slightly revised by the authors and updated here on 25/07/2012. Please see paragrapghs 8 and 9 below the fold for the updated text.

The 76 page Belfer Centre pdf can be downloaded here. This critique by Sorrell and McGlade first appeared in the ODAC newsletter here.

Commentary on: Oil: 'The Next Revolution: The Unprecedented Upsurge of Oil Production Capacity and What it Means for the World' - Leonardo Maugeri, Belfer Center for Science and International Affairs, Harvard University

Summary Maugeri's analysis and conclusions are critically dependent upon the decline rates applied to existing and future fields, and yet he does not explicitly say what these decline rates will be. However, Maugeri’s assumptions can be derived from his Table 2, which projects gross and net capacity additions over the period to 2020. Doing so suggests he uses an average annual decline rate for all fields of 1.6% over this period, which is less than half of the IEA and CERA estimates for 2008 (4.1%/year and 4.5%/year respectively). The discrepancy is even greater since the IEA and other analysts project an increase in average decline rates over the 2011-20 period. If we replace Maugeri’s 1.6% decline rate assumption with the IEA estimate of 4.1%, the projected loss of production capacity over the period to 2020 increases from 11 mb/d to 26.5 mb/d. In turn, the projected global production capacity in 2020 reduces from 110.6 mb/d to 95.1mb/d (a reduction of 14%). Since average decline rates would be expected to increase over this period, this projection must be considered optimistic.