5.4.2.4 Totals

The estimates discussed above can be summarized as follows:

Light-duty vehicles:

718–766 MtCO₂ at carbon prices less than 100 US$/tCO₂

689–718 MtCO₂ at carbon prices less than 50 US$/tCO₂

669–718 MtCO₂ at carbon prices less than 20 US$/tCO₂

369–697 MtCO₂ at carbon prices less than 0 US$/tCO₂

Aircraft:

150 MtCO2 at carbon prices less than 50 US$/tCO₂

280 MtCO₂ at carbon prices less than 100 US$/tCO₂

Biofuels:

600–1500 MtCO₂ at carbon prices less than 25 US$/tCO₂

Although presumably the potential for biofuels penetration would be higher above the cited 25 US$/tCO₂ carbon price, the total potential for a carbon price of 100 US$/tCO₂ for the three mitigation sources is about 1600–2550 MtCO₂. Much of this potential appears to be located in OECD North America and Europe. Note, however, that the potential is measured as the ‘further’ reduction in CO₂ emissions from the Reference scenario, which assumes that substantial amounts of biofuels will be produced in Brazil and elsewhere and significant improvements in fuel efficiency will occur in China and in other industrializing nations without further policy measures.