Warming World, Potent Poppies

After collecting the opium gum, Ziska measured its constituents and compared them to a reference collection kept by the Drug Enforcement Agency’s Special Testing and Research Laboratory. Ziska found that not only did poppies produce more opium gum when grown in chambers with higher carbon dioxide levels, but the concentration of morphine in the gum also increased. He published his results in the May 2008 edition of the journal Climatic Change.

Climate change experts called the study’s results intriguing, but they point out that plants in the wild may behave differently. “This study shows the potential of individual plants,” says Peter Reich, an ecologist at the University of Minnesota, who was not involved in the study. But, he adds, “competing with the same species, or with other wild plants, changes the [growing] conditions.”

In real world conditions, Reich says, the effects of higher carbon dioxide are probably not as extreme as Ziska’s results suggest. “Interactions between plants and competitors, diseases, decomposers and bacteria affect fertility,” and the compounds plants produce, says Reich.

Ziska doesn’t dispute Reich’s comments, and is hoping that future studies will model real-world growing conditions more closely. He also advocates studying other plants, including the poppy P. somniferum. Large scale commercial poppy operations, both legal and illegal, collect opiates from P. somniferum. Since this species is closely related to P. setigerum, Ziska expects to see morphine increases in this plant as well.

Although climate change’s effects on plant biology are unpredictable, public pharmaceutical and medical reliance on these crops remains as important as ever. “What I find particularly surprising is not the science,” says Ziska, but the question: “Why aren’t people looking at this?”

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