Soot from road traffic in emerging countries can reach high altitudes, where it can be transported over long distances and thus contributes to global warming. This is the conclusion of a study performed by an international team of researchers in the Bolivian cities of La Paz (the seat of government), El Alto and the neighboring Chacaltaya mountain observatory. The reduction of pollutants from road traffic such as soot particles from diesel cars should therefore have high priority in order to both protect the health of the population in the growing conurbations of emerging countries and reduce global warming. The results have been published in the journal Atmospheric Environment.