Last November Ray Pierrehumbert at RealClimate was very disappointed in a New York Times article by William Broad:
The worst fault of the article, though, is that it leaves the reader with the impression that there is something in the deep time Phanerozoic climate record that fundamentally challenges the physics linking planetary temperature to CO2. This is utterly false, and deeply misleading.
This article is far from the standard of excellence in reporting we have come to expect from the Times. We sincerely hope it’s an aberration, and not indicative of the best Mr. Broad has to offer.
Alas, it’s not an aberration. Broad has done it again, with an article where he gives global warming skeptics (who are “centrist” according to Broad) free rein to say anything they want, without checking the accuracy of their claims. Worse, he adds his own statements on the science that seriously misrepresent scientific reports.
Broad is trying to make the case that the scientific “middle ground in the climate debate” is criticising Gore for alarmism. Trouble is, most of the critics he quotes are not from the middle at all, but are skeptics who reject the scientific consensus. He has skeptics Benny Peiser, Roy Spencer, Richard Lindzen, Bob Carter, Don Easterbrook, Bjorn Lomberg and Paul Reiter. Broad identifies a couple of these as skeptics, but misleads his readers by making it appear that the others are from the middle.
It gets worse. Broad simply misrepresents the findings of the IPCC to make it appear that they contradict Gore.
Some of Mr. Gore’s centrist detractors point to a report last month by the Intergovernmental Panel on Climate Change, a United Nations body that studies global warming. The panel went further than ever before in saying that humans were the main cause of the globe’s warming since 1950, part of Mr. Gore’s message that few scientists dispute. But it also portrayed climate change as a slow-motion process.
It estimated that the world’s seas in this century would rise a maximum of 23 inches — down from earlier estimates. Mr. Gore, citing no particular time frame, envisions rises of up to 20 feet and depicts parts of New York, Florida and other heavily populated areas as sinking beneath the waves, implying, at least visually, that inundation is imminent.
The IPCC report absolutely did not say the maximum sea level rise this century would be 23 inches. Gore talks about the changes in ice flows in Greenland and Antarctica and states that if half of the ice sheets in Greenland and West Antarctica melted, sea levels could rise 20 feet (6 metres). The maximum sea level rise that Broad quoted does not include this effect.
Models used to date do not include uncertainties in climate-carbon cycle feedback nor do they include the full effects of changes in ice sheet flow, because a basis in published literature is lacking. The projections include a contribution due to increased ice flow from Greenland and Antarctica at the rates observed for 1993-2003, but these flow rates could increase or decrease in the future. For example, if this contribution were to grow linearly with global average temperature change, the upper ranges of sea level rise for SRES scenarios shown in Table SPM-2 would increase by 0.1 m to 0.2 m. Larger values cannot be excluded, but understanding of these effects is too limited to assess their likelihood or provide a best estimate or an upper bound for sea level rise.
The report also states:
The last time the polar regions were significantly warmer than present for an extended period (about 125,000 years ago), reductions in polar ice volume led to 4 to 6 metres of sea level rise.
So sea levels could rise by 6 metres as Gore suggests. And the scientists don’t know how long it would take, so Gore did not present a time frame for the rise.
But even that is not the worst of Broad’s misrepresentations. Check this out:
So too, a report last June by the National Academies seemed to contradict Mr. Gore’s portrayal of recent temperatures as the highest in the past millennium. Instead, the report said, current highs appeared unrivaled since only 1600, the tail end of a temperature rise known as the medieval warm period.
That’s actually the opposite of what the report said:
There is sufficient evidence from tree rings, boreholes, retreating glaciers, and other “proxies” of past surface temperatures to say with a high level of confidence that the last few decades of the 20th century were warmer than any comparable period in the last 400 years, according to a new report from the National Research Council. Less confidence can be placed in proxy-based reconstructions of surface temperatures for A.D. 900 to 1600, said the committee that wrote the report, although the available proxy evidence does indicate that many locations were warmer during the past 25 years than during any other 25-year period since 900. Very little confidence can be placed in statements about average global surface temperatures prior to A.D. 900 because the proxy data for that time frame are sparse, the committee added. …
The committee noted that scientists’ reconstructions of Northern Hemisphere surface temperatures for the past thousand years are generally consistent. The reconstructions show relatively warm conditions centered around the year 1000, and a relatively cold period, or “Little Ice Age,” from roughly 1500 to 1850. The exact timing of warm episodes in the medieval period may have varied by region, and the magnitude and geographical extent of the warmth is uncertain, the committee said. None of the reconstructions indicates that temperatures were warmer during medieval times than during the past few decades, the committee added.
The report agrees with Gore and does not say that it was warmer in medieval times. Just to be clear here — I don’t think that Broad deliberately lied about the report. I imagine that he didn’t bother to read it, but wrote down what his global warming skeptics told him. But he should have checked and he didn’t.
Update: RealClimate think that Broad is being dishonest.