A recent meta-analysis of the fossil energy outlooks used for climate change scenarios even identified a "return to coal hypothesis", as most mainstream climate scenarios foresee a significant increase in world coal production in the future. Patzek and Croft (2010, p. 3113) made a prediction of future coal production and carbon emissions. In their assessment, all but the lowest emission SRES scenarios projected far too high levels of future coal production and carbon emissions (Patzek and Croft, 2010, pp. 3113–3114). Similar results was reached by other long-term coal projections