by Judith Curry
The American Meteorological Society 2011 Award for Distinguished Science Journalism in the Atmospheric and Related Sciences goes to . . .
Quirin Schiermeier for his article published in Nature, entitled “The real holes in climate science.” The citation on the award is: “For “The Real Holes in Climate Science”, an insightful and candid article on key remaining gaps in understanding climate change.”
The subtitle on the article is “Like any other field, research on climate change has some fundamental gaps, although not the ones typically claimed by sceptics. Quirin Schiermeier takes a hard look at some of the biggest problem areas.”
In its most recent report in 2007, the Intergovernmental Panel on Climate Change (IPCC) highlighted 54 ‘key uncertainties’ that complicate climate science.
Such a declaration of unresolved problems could hardly be called ‘hidden’. And some of these — such as uncertainties in measurements of past temperatures — have received consid- erable discussion in the media. But other gaps in the science are less well known beyond the field’s circle of specialists. Such holes do not undermine the fundamental conclusion that humans are warming the climate, which is based on the extreme rate of the twentieth-century temperature changes and the inability of climate models to simulate such warming without including the role of greenhouse-gas pollution. The uncertainties do, however, hamper efforts to plan for the future. And unlike the myths regularly trotted out by climate-change denialists, some of the outstanding problems may mean that future changes could be worse than currently projected.
A perspective from Gavin Schmidt (note: this article was published Jan 2010, in the wake of Climategate 1.0):
Researchers say it is difficult to talk openly about holes in understanding.
“Of course there are gaps in our knowledge about Earth’s climate system and its components, and yes, nothing has been made clear enough to the public,” says Gavin Schmidt, a climate modeller at NASA’s Goddard Institute for Space Studies in New York and one of the moderators and con- tributors to the influential RealClimate blog. “But this climate of suspicion we’re working in is insane. It’s really drowning our ability to soberly communicate gaps in our science when some people cry ‘fraud’ and ‘misconduct’ for the slightest reasons.”
JC comment: seems to me that Gavin is confusing cause and effect. People cry ‘fraud’ and ‘misconduct’ when they perceive that scientists are trying to hide uncertainties.
The article focuses on the following four ‘holes’: regional climate forecasts, precipitation forecasts, aerosols and palaeoclimate data.
Regional climate predictions: the money quotes are from Smith and von Storch:
“Our current climate models are just not up to informed decision-making at the resolution of most countries,” says Leonard Smith, a statistician and climate analyst at the London School of Economics and Political Science.
“You need to be very circumspect about the added value of downscaling to regional impacts,” agrees Hans von Storch, a climate modeller at the GKSS Institute for Coastal Research in Geesthacht, Germany, who has recently contributed to a regional climate assess- ment of the Hamburg metropolitan region. If the simulations project future changes in line with the trends already observed, von Storch has more confidence in them. But if researchers run the same model, or an ensemble of models, multiple times and the results diverge from each other or from the observed trends, he cautions, “planners should handle them with kid gloves. Whenever possible, they’d rather wait with spending big money on adaptation projects until there is more certainty about the things to come.”
The different simulations used by the IPCC in its 2007 assessment offer wildly diverging pictures of snow and rainfall in the future. The situation is particularly bad for winter precipitation, generally the most important in replenishing water supplies. The IPCC simulations failed to provide any robust projection of how winter precipitation will change at the end of the current century for large parts of all continents.
Even worse, climate models seemingly underestimate how much precipitation has changed already — further reducing confidence in their ability to project future changes. A 2007 study, published too late to be included into the last IPCC report, found that precipitation changes in the twentieth century bore the clear imprint of human influence, including drying in the Northern Hemisphere tropics and subtropics. But the actual changes were larger than estimated from models — a finding that concerns researchers.
“If the models do systematically underestimate precipitation changes that would be bad news”, because the existing forecasts would already cause substantial problems, says Gabriele Hegerl
JC comment: the possibility that multidecadal natural variability is a major driver of rainfall variability does not seem to be considered. The poor performance of the climate models somehow gives rise to greater alarm about the future. Go figure.
One of the biggest problems is lack of data. “We don’t know what’s in the air,” says Schmidt. “This means a major uncertainty over key processes driving past and future climate.”
JC comment: +1 for Gavin on this statement. It is greatly at odds with the Hegerl et al. reply to my assertions about uncertainty in aerosol forcing in the uncertainty monster paper.
Re the tree ring controversy, +1 to Hegerl for her comments on the divergence issue:
“They show what was, at the time, the best estimate of how temperatures evolved over time,” says Hegerl. “However, with hindsight, they could have been a bit clearer how this was done, given the high profile that figures like this can have.”
“I’m worried about what causes the divergence,” says Hegerl. “As long as we don’t understand why they diverge, we can’t be sure that they accurately represent the past.”
The article’s concluding statement:
Even with ongoing questions about the proxy data, the IPCC’s key statement — that most of the warming since the mid-twentieth century is “very likely” to be due to human-caused increases in greenhouse-gas concentration — remains solid because it rests on multiple lines of evidence from different teams examining many aspects of the climate system, says Susan Solomon, the former co-chair of the IPCC team that produced the 2007 physical science report . . . “The IPCC’s team of scientists,” she says, “would not have said that warming is unequivocal based on a single line of evidence — even if came from Moses himself.”
JC comment: -1 for Susan Solomon. The misleading oversimplicity of the multiple lines of evidence argument was discussed previously here (section 5). The uncertainties in the paleoclimate record and the aerosol forcing discussed in Schiermeier’s article are alone sufficient to question the high confidence in the IPCC’s attribution statement.
When the paper was published in January 2010, it wasn’t discussed at Climate Etc. (which did not yet exist), but was discussed by Pielke Sr., Bishop Hill and Climate Resistance. Bishop Hill has this to say about the article:
It tends to reiterate lines of argument that are familiar to anyone who has followed the pronouncements of the Hockey Team in recent years. This is hardly surprising when one looks at who he chose to interview – Gavin Schmidt, Jonathan Overpeck, Gabriele Hegerl, Susan Solomon, Hans von Storch, and an economist called Leonard Smith. Not a sceptic among them and four of them being Hockey Team members.
Schiermeier claims that the divergence problem is restricted to “a few northern hemisphere sites”, directly contradicting Keith Briffa who has referred to it as “a widespread problem” in the NH.
JC conclusion: I agree with Pielke Sr’s summary statement on the article:
The article is a step forward from other news summaries of climate science. However, it still perpetuates significant misunderstandings and erroneous conclusions about our actual understanding of the climate system.
The article raises the important issue of the holes in climate science, but only seeks perspectives from establishment scientists. The ‘enduring myths’ section is not effectively rebutted at all (Pielke Sr’s post takes this on).
With regards to the AMS Award, this article, even with its flaws, is to be applauded for taking on this topic in some depth.
With regards to the 4 topics selected, I agree that these 4 are all pretty big holes in climate science. I was dismayed not to see any mention of natural variability (even in “enduring myths”), other than this statement on precipitation: “We really don’t know natural variability that well, particularly in the tropics,” says Hegerl. (JC comment: personally I think the holes are greater in the mid/high latitudes).
What are your thoughts on the biggest holes in climate science?