Research Highlights

Nature Reports Climate Change
Published online: 26 June 2008 | doi:10.1038/climate.2008.65

More potent poppies

Alicia Newton

Climatic Change doi:10.1007/s10584-008-9418-9 (2008)

ALAMY

Poppies will grow larger and produce more opiates as atmospheric carbon dioxide levels rise, say scientists. Cultivated for their use in legitimate pharmaceuticals, the delicate flowers are perhaps best known as the primary source of illegal drugs such as heroin.

Lewis Ziska at the US Department of Agriculture in Maryland and colleagues grew wild poppies, which are closely related to opium poppies, under atmospheric carbon dioxide concentrations equivalent to those in 1960, at present levels and at higher levels that could be reached by 2050 and 2090 if current emissions trends continue. The biomass and leaf area of the plants increased significantly at higher concentrations of the greenhouse gas, and far more raw opiates were produced, with morphine showing the greatest rise.

Earlier studies have suggested that higher temperatures could also boost opium production. The amount of opiates per plant will continue to rise for at least 50 years — though not as considerably as in the last half-century — before levelling off, say the researchers. The study adds to existing evidence that plants are already showing physiological responses to the anthropogenic rise in atmospheric carbon dioxide.