It represents a halt of emissions from deforestation and forest degradation including on peatland, and universal 'wide-scale' forest restoration on available and suitable areas. This represents an upper technical maximum and is estimated to be around 9 GtCOj in 2030 (range: 6.7-11.9) (Table 6.1). Factors that can place increased demands on forest land include limited capacity to increase production in agriculture, national objectives for food self-sufficiency, infrastructure development, and wood product requirements. Demands can be reduced by factors such as restoring degraded lands to agricultural production, changing dietary preferences or reducing waste. The range reflects uncertainty in data sources, use of different methodologies to estimate emissions, and differences in the land use change processes included, the range of emission sources included and the land-cover definitions adopted (Houghton et al., For example, the forest definitions used in international analyses are frequently based on those used by FAO's Global Forest Resources Assessment (forest area >0.5 ha, tree height >5 m and canopy cover >10 per cent, or trees able to reach these thresholds in situ, not predominantly under agricultural or urban use) (IPCC, 2006, FAO, 2010a).