At EarthSky.org, we aim to be a clear voice for science, but science doesn’t always proceed in a clear, stepwise fashion with unambiguous results and instant agreement on all sides. Sometimes new studies come out that contradict each other, as scientists struggle to learn how our world works. For many people — including journalists — this can create a kind of whiplash. In recent years this has been true of climate change research; the New York Times’ Andrew Revkin examined climate change whiplash in an article this week.
There seems to be a new climate study published every day, which often gives me climate fatigue. Revkin illustrates this in his story:
“Discordant findings have come in quick succession. How fast is Greenland shedding ice? Did human-caused warming wipe out frogs in the American tropics? Has warming strengthened hurricanes? Have the oceans stopped warming? These questions endure even as the basic theory of a rising human influence on climate has steadily solidified: accumulating greenhouse gases will warm the world, erode ice sheets, raise seas and have big impacts on biology and human affairs.”
“Scientists see persistent disputes as the normal stuttering journey toward improved understanding of how the world works. But many fear that the herky-jerky trajectory is distracting the public from the undisputed basics and blocking change. ‘One of the things that troubles me most is that the rapid-fire publication of unsettled results in highly visible venues creates the impression that the scientific community has no idea what’s going on,’ said W. Tad Pfeffer, an expert on Greenland’s ice sheets at the University of Colorado.” (Quoted passages are from “Climate Experts Tussle Over Details. Public Gets Whiplash,” by Andrew Revkin)
I think scientists do know what’s going on, in terms of the big picture: Climate change is happening and human activities have very likely contributed to warm the planet. Scientists are virtually 100 percent certain about the first part, and 90 percent certain about the second. Journalists and the public would do well to keep those two things in mind when confronted with a new study about some aspect of climate change.
Some journalists do place their stories into the context of the sum of climate-science knowledge at the time, but others do not. The 24-hour media cycle, with Internet and cable outlets desperate for new content, means that each new climate study gets mentioned in some way. Often there’s not time to put it in context, especially on TV. So we get a sensational headline or teaser and a short report highlighting the most extreme or sensational element of the scientific study — not necessarily the incremental gain made by the scientist, nor the unknowns remaining.
One example of leaving out context that comes to mind is the recent coverage of methane emissions from cows — cow farts and smelly cow dung — and how emissions from agriculture (worldwide) amount to more than those from transportation. And that methane is 23 times more potent a greenhouse gas than carbon dioxide. There seems to be a cow fart crisis! (The cow coverage may have been spurred in early July by a quirky cow experiment going on in Argentina.)
But I looked at the International Panel on Climate Change’s “AR4 Synthesis Report — Summary for Policymakers” from November 2007 and it notes that “methane growth rates have declined since the early 1990s, consistent with total emissions being nearly constant during this period.” So methane may be a potent greenhouse gas, but if its levels are staying constant in the atmosphere, are cow farts really a crisis?
If you look at page 5 of that Synthesis Report, there is a figure (shown here) with nice graphs and charts showing global anthropogenic greenhouse gas emissions. Since 1970, CO2 levels from fossil fuel use and deforestation have been rising, as have levels of nitrous oxide. Methane seems to stay constant.
In the pie chart of greenhouse gases by sector, Agriculture contributes 13.5 percent of the gases, while Transport creates 13.1 percent — not a huge difference. In contrast, three other sectors trump those two: Energy supply (at 25.9 percent), Industry (19.4 percent) and Forestry (17.4 percent). So Agriculture — that’s the entire sector, not just cows — is number four on the list.
The Chicago Tribune story about cow methane that I linked to is a pretty good story (I found it quickly on Google and I bet there were other blogs and sites that did not cover cows so thoroughly), but for me it lacked the few bits of information I’ve cited in order to give context to the issue. Yes, agriculture contributes a decent chunk of greenhouse gases and lots of folks are working on innovative ways to reduce those gases. But if methane levels are not rising, and CO2 levels are, tell us so. Put it in perspective.
Okay, I’m off my soapbox. Your turn to chime in: What do you think of climate change coverage in the media? Is methane a big issue or not? Post your comments here!