with values of WEO* *For past and future projections, the model fits well with WEO values in terms of oil demand-R-square of 98.3 per cent and average point-to- point deviation 0.69 per cent.
of fossil fuels, nuclear and renewable energy will increase from 10,174 Mtoe, 755 Mtoe and 1,620 Mtoe respectively in 2011, to reach 16,073 Mtoe, 1,089 Mtoe, and 2,577 Mtoe respectively in 2050, with the share of fossil fuels remaining at 81 per cent throughout 2050.
For oil demand, among other fossil fuels, the simulated trends of growth in BAU and corresponding WEO values are illustrated in Figure 6. The projection of oil price follows IEA’s WEO, and increases faster after 2030, due to the peak of conventional oil projected to take place after 2035.
Driven by the same factors, total water consumption is projected to reach 8,141 km3
in 2050 – 70 per
cent above its current value – with total water supply heavily relying on groundwater reservoirs and streams well beyond sustainable withdrawals. This production level would probably compromise aquifers, increasing salt-water infiltration in coastal areas and forcing massive migrations.
Billion hectares 4 3 2 1 0
1970 1975 1980 1985 1990 1995 2000 2005 Arable land
Forestland
BAU scenario FAOSTAT
BAU scenario FAOSTAT
Figure 7: Simulation of arable land and forestland in BAU compared with values of FAOSTAT 516 2010 2015 2020 2025 2030 2035 2040 2045 2050
Concerning land use, total agricultural land will expand to 5.4 billion hectares by 2050, with pasture and arable land growing by 11 per cent and 6 per cent between 2010 and 2050. The harvested area in turn will reach 1.3 billion hectares by 2050, a 9 per cent increase relative to 2010 to meet the increasing food demand. In addition, settlement land will grow by 0.7 per cent per year on average, reaching 226 million hectares in 2050. Correspondingly, forestland will suffer from an average net loss of 6 million hectares per year and a deforestation rate of 15 million hectares per year, with only 3.7 billion hectares of forestland left by 2050. As a result, the total carbon storage in forests will decline by about 7 per cent between 2010 and 2050. The fishery sector will also face challenges such as declining stocks. The total amount of fish caught is projected to decline by as much as 46 per cent between 2010 and 2050, due to overcapacity and ineffective management of the industry and natural resources.
Finally, owing to the larger population and higher income, the world is expected to generate over 13.2 billion tonnes of waste in 2050, 19 per cent higher than the amount in 2009.
As a consequence of these trends, total world CO2 emissions are projected to increase throughout the
simulation, with fossil fuel emissions reaching about 50 billion tonnes (Gt) per year in 2050, 71 per cent above 2009 and 138 per cent above 1990 emission levels (Figure 8). This increase corresponds also to a 26 per cent reduction in global carbon intensity (calculated as emissions per US$ of GDP) between 2009 and 2050. The transport sector, as a major emitter, will account of 13 Gt