Plants Produce Methane? That's So 2006

In January 2006, after scientists reported in Nature that plants release between 10 percent and a third of all atmospheric methane, science journalists scrambled to cover the blockbuster news.

It was a surprise just in terms of basic biology--scientists have been studying the gases released by plants for a long time, and so it was surprising that they could have missed such a giant belch. Making the matter of pressing interest was methane’s ability to trap heat in the atmosphere. Suddenly plants became a much bigger player in the global warming game.

Many news outlets covered the paper, and many made a muddle of it. Their wording implied that the scientists were claiming that plants, not humans, might be responsible for the recent rise in the global average temperature. The Max Planck Institute released a press release clarifying that plants are not to blame, and the Guardian and National Geographic published corrections.

Some pundits didn’t heed the scientists, though. At Foxnews.com, columnist Steven Milloy declared that deforestation ought to reduce global warming. [...] The folks from the Wall Street Journal editorial page declared that “this is causing big problems for the tree-huggers.”

Eighteen months later, a new study shows that plants probably don't emit much methane after all. But the new study has barely been covered -- and Carl Zimmer, one of the best science journalists around, wonders why.

If the original paper was so important that it should go on newswires and appear in newspapers and magazines, then what makes this new one less so?

Two forces are at play here. One is that the huge premium in the science writing world on stories about new ideas. It was such a shock to think that methane was churning out of plants, particularly with global warming becoming such a hot topic. The science writing machine is much worse at follow-up. Does the editorial unconscious say, “Hey, we’ve already written about that. Let’s move on”? Or perhaps it would look bad to say, “Remember that story with the big headline a while back? Well never mind, looks like it may have been wrong.” But ignoring these follow-up papers does a disservice to science. Science is not about single major discoveries, but about the flow of research, of debate and hypothesis-testing.

The other problem dwells, I’d suggest, within the scientific community.
I like New Phytologist a lot, but it’s not a high-profile journal. The scientific community tends to present bold new claims in high-profile journals like Nature, while the essential follow-up ends up relegated to more specialized journals that attract less attention. I for one stumbled on this paper by chance. So scientists themselves may be contributing to the distorted view people have of the scientific process.

The Missing News of the Missing Methane [The Loom]
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Image: BBC*