How much land is available for reforestation?

2.3bn hectares of land have been deforested, releasing c25% of all anthropogenic emissions. This 19-page note reviews the technical literature, gathers detailed data and concludes 1.2bn hectares can be reforested. Consequently, there is room for 85Mbpd of oil and 400TCF of gas in a decarbonized energy system, while half of all ‘new energies’ technologies are overly expensive and may not be needed in the transition.