Climatologists probably need to take a stiff drink before they open the papers (or fire up their web browsers) the morning after their studies appear in print or online. Two if the studies involved say anything interesting about global warming. Today’s coverage of a Nature paper that predicts a decade-long, regional cooling trend for Europe and North America is sure to give the authors the jitters.
Noel Keenlyside of the Leibniz Institute of Marine Sciences in Kiel, Germany, and his co-authors laced their letter with caveats. They call their attempt to model the effects of meridional overturning circulation “a simple approach” and note that they are working with surface temperatures when what they really need are subsurface records. But most observers seem to think they are at least giving the climate science community lots to think about when they conclude that global average surface temperatures could stop rising until the end of the next decade thanks to natural ocean cycles.
Good science reporters, like the NY Times’ Andy Revkin, assembled a story that almost bends over backwards to play down the significance of the study. In other words, he’s writing like a scientist. Under the headline “In a New Climate Model, Short-Term Cooling in a Warmer World” Revkin takes his time getting to the juicy/controversial bit:
After decades of research that sought, and found, evidence of a human influence on the earth’s climate, climatologists are beginning to shift to a new and similarly daunting enterprise: creating decade-long forecasts for climate, just as meteorologists routinely generate week-long forecasts for weather.
One of the first attempts to look ahead a decade, using computer simulations and measurements of ocean temperatures, predicts a slight cooling of Europe and North America, probably related to shifting currents and patterns in the oceans.
The team that generated the forecast, whose members come from two German ocean and climate research centers, acknowledged that it was a preliminary effort. But in a short paper published in the May 1 issue of the journal Nature, they said their modeling method was able to reasonably replicate climate patterns in those regions in recent decades, providing some confidence in their prediction for the next one.
On the other hand, the Telegraph’s science editor,Charles Clover, chooses the sensationalist and misleading headline of “Global warming may ‘stop’, scientists predict.”
Researchers studying long-term changes in sea temperatures said they now expect a “lull” for up to a decade while natural variations in climate cancel out the increases caused by man-made greenhouse gas emissions.
The average temperature of the sea around Europe and North America is expected to cool slightly over the decade while the tropical Pacific remains unchanged.
This would mean that the 0.3°C global average temperature rise which has been predicted for the next decade by the UN’s Intergovernmental Panel on Climate Change may not happen, according to the paper published in the scientific journal Nature.
Reaction from climatologists to the letter in Nature, according to Revkin, represents a “variety of views.” Reaction to the coverage is not as complimentary. Real Climate’s Gavin Schmidt, says “The NYT story is ok, but the Telegraph is appalling.”
“Appalling” might be too strong as word, as Clover does bother to refer to Keenlyside’s observations that
“…the results were just the initial findings from a new computer model of how the oceans behave over decades and it would be wholly misleading to infer that global warming, in the sense of the enhanced greenhouse effect from increased carbon emissions, had gone away.
But the headline is what does the damage. And the Telegraph should know better. Global warming is not going to stop. All these particular natural cycles do is redistribute heat, in this case keeping more of it deep underwater instead of moving into the lower atmosphere. The total amount of heat being trapped by carbon in the air continues to rise. (Other natural cycles, like the Milankovitch orbital cycles, do change the total of amount of heat energy, on Earth, but that’s not what’s being discussed.) This is why writing that global warming will stop is dead wrong.
What the Keenlyside paper does predict is that even after the short-term cooling, warming will only “temporarily offset the projected anthropogenic warming” before it catches up to conventional predictions by the 2020s, and we’re right back to where we started.
Even this isn’t really earth-shattering. Last year the Hadley Centre, the UK’s leading climate change lab, published a paper in Science that predicted a similar but shorter cooling trend that ends in late 2009, after which half of the next 10 years will be warmer than recent records. And James Hansen also predicts a short period of flat temperatures due to natural cycles. None of which changes anything when it comes to the longer term.
[Update: U.S. Sen. Jim Inhofe posted a predictably misleading take on the study. And not too surprisingly, his staffer, Marc Morano, chose to go with a piece of the Telegraph's unfortunate headline.]
Keenlyside, N.S., Latif, M., Jungclaus, J., Kornblueh, L., Roeckner, E. (2008). Advancing decadal-scale climate prediction in the North Atlantic sector. Nature, 453(7191), 84-88. DOI: 10.1038/nature06921