The known particular effects of each of these local pollutants are reviewed briefly in
section A below, and in more detail in annex I to the present report. In this report, both the global
and local by -product pollutants of fossil-fuel combustion will be referred to simply as
“emissions”, except when there is a need to distinguish between them. Conceptually they share a
trait that simplifies policy discussions somewhat: “less is better”. The amount of transport -sector
emissions is roughly correlated with the amount of fossil fuel used in combustion in the sector,
but the correlation is significantly more straightforward for global pollutants–particularly CO2–
than for local ones