Here's a story that should be getting lots of press but apparently isn't: a new study indicates that plants don't release lots of methane gas.
You may perhaps recall a lot of attention paid to methane from plants back in January 2006. A team of scientists (mostly from the Max Planck Institute for Nuclear Physics) reported in Nature that they had found evidence that plants release huge amounts of the gas--perhaps accounting for ten to thirty percent of all the methane found in the atmosphere.
The result was big news for several reasons. 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 Society 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. "Our understanding of global climate system is woefully insufficient to support the rush-to-judgment advocated by celebrity-backed global warming alarmists," he claimed. The folks from the Wall Street Journal editorial page declared that "this is causing big problems for the tree-huggers." Rush Limbaugh sarcastically said, "Well, hot damn. God is to blame for global warming."
Fast-forward eighteen months. A group of Dutch researchers put the Max Planck team's conclusions to the test by tracing radioactive carbon isotopes through plants. Their conclusion: "There is no evidence for substantial aerobic methane emission by terrestrial plants."
The paper went online today, published in the journal New Phytologist. (It's free here.) The publisher sent out a press release, but my search has turned up almost no news coverage. There were three stories that were nothing more than cut-and-paste copies of the press release. I found just one piece of original reporting, at a site called Chemistry World, which I now intend to read regularly. The article casts the new paper as the first in a series of new publications that support both sides of this methane vs no-methane debate.
I do not expect that Rush Limbaugh will bother mentioning this paper. The world of punditry leaves me generally baffled. But as a science writer, I'm disappointed that this paper is not getting reported more in the press. 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.
It's always possible that I'm mistaken, and that the discovery of the missing methane will bubble up more into the mainstream media in the next few days. Prove me wrong, fellow scribes, and I'll be happy.
