by Judith Curry
The Guardian strikes back against David Rose’s Daily Mail article.
Dana Nuccitelli (of Skeptical Science) has an article posted in The Guardian entitled Why the Daily Mail was wrong to claim that global warming has stopped, with subtitle “Newspaper’s claim that ‘world stopped getting warmer almost 16 years ago’ is simply wrong, says Met Office” Excerpts:
The Skeptical Science temperature trend calculator can be used to test this question. The trend in the HadCRUT4 global surface temperature dataset since 1997 is 0.084 ± 0.152°C per decade (although we have not yet updated the HadCRUT4 data, the GISS and NCDC datasts show a similar warming trend since 1997). While the trend is not statistically significant, the central value is positive, meaning the average surface temperature has most likely warmed over this period.
JC comment: how does this refute Rose’s argument? No statistically significant positive trend, and it makes it look like SkS hasn’t done their homework with the latest data.
The Met Office also explained that Rose is essentially trying to go down the up escalator by focusing on short-term noise while ignoring the long-term trend.
JC comment: How many statements have we seen from the Met Office and IPCC principles about the expectation from the models that there should be no plateau or cooling period exceeding 15-17 years? Nuticelli even includes this quote from the Met Office:
“The models exhibit large variations in the rate of warming from year to year and over a decade, owing to climate variations such as ENSO, the Atlantic Multi-Decadal Oscillation and Pacific Decadal Oscillation. So in that sense, such a period is not unexpected. It is not uncommon in the simulations for these periods to last up to 15 years, but longer periods are unlikely.”
JC comment: Now for a circular reasoning alert:
Figure 4: Estimation of the observed signature of internal variability in the observed 20th century global mean temperature in climate model simulations
Rose and Curry are trying to argue that because global surface temperatures have not warmed as fast as the multi-model average in the IPCC report (0.2°C per decade), this somehow suggests the models are flawed.
JC comment: Nuccitelli argues that the models are right, and therefore greenhouse warming dominates over natural warming. I argue that climate models are imperfect and incomplete, a statement that no climate modeler on the planet would argue with.
JC note to defenders of the idea that the planet has been warming for the past 16 years:
Raise the level of your game. Nothing in the Met Office’s statement or in Nuticelli’s argument effectively refutes Rose’s argument that there has been no increase in the global average surface temperature for the past 16 years.
Use this as an opportunity to communicate honestly with the public about what we know and what we don’t know about climate change. Take a lesson from these other scientists that acknowledge the ‘pause’, mentioned in my previous post Candid comments from global warming scientists
Kevin Trenberth:
The hiatus [in warming] was not unexpected. Variability in the climate can suppress rising temperatures temporarily, though before this decade scientists were uncertain how long such pauses could last. In any case, one decade is not long enough to say anything about human effects on climate; as one forthcoming paper lays out, 17 years is required
Trenberth questions whether the Argo measurements are mature enough to tell as definite a story as Hansen lays out. He has seen many discrepancies among analyses of the data, and there are still “issues of missing and erroneous data and calibration,” he said. The Argo floats are valuable, he added, but “they’re not there yet.”
Susan Solomon:
“What’s really been exciting to me about this last 10-year period is that it has made people think about decadal variability much more carefully than they probably have before,” said Susan Solomon, an atmospheric chemist and former lead author of the United Nations’ climate change report, during a recent visit to MIT. “And that’s all good. There is no silver bullet. In this case, it’s four pieces or five pieces of silver buckshot.”
Jim Hansen:
These revelations are prompting the science’s biggest names to change their views.
Indeed, the most important outcome from the energy hunt may be that researchers are chronically underestimating air pollution’s reflective effect.
“Less efficient mixing, other things being equal, would mean that there is less warming ‘in the pipeline,’” Hansen said. “But it also implies that the negative aerosol forcing is probably larger than most models assumed. So the Faustian aerosol bargain is probably more of a problem than had been assumed.”
Judith Lean:
Climate models failed to reflect the sun’s cyclical influence on the climate and “that has led to a sense that the sun isn’t a player,” Lean said. “And that they have to absolutely prove that it’s not a player.”