Not only did coca bush cultivation continue to decline in 2013, reaching the lowest level since 1990, when estimates first became available, but the annual prevalence of cocaine use (0.4 per cent of the adult population) also continued to decline in Western and Central Europe and North America. In those subregions, which, along with South America, have the world's largest cocaine markets, the prevalence of cocaine use is highest. Supply reduction measures may have contributed to the decline in coca bush cultivation in the coca-producing countries, leading to a reduction in the availability of cocaine and the shrinking of some of the principal cocaine markets.
In addition to the human cost of cocaine manufacture and trafficking, illicit coca bush cultivation and the transformation of coca into cocaine continue to cause serious environmental damage even though coca bush cultivation has decreased. In Colombia alone, roughly 290,000 hectares of forest were lost as a direct result of coca crop cultivation between 2001 and 2013, while the slash-and-burn method used to clear new plots has led to increased erosion. Further environmental damage has been caused by the herbicides and fertilizers used in coca bush cultivation and the chemicals employed in the transformation of coca into cocaine.