In May 2006, at the time of the theatrical release of An Inconvenient Truth, the documentary of former Vice President Al Gore's presentation about global warming, The New York Times published an article by Andrew C. Revkin, in which Revkin reported that mainstream scientists, while taking issue with details in the film, embraced its premise, subscribing to Gore's "main point." But 10 months later, shortly after An Inconvenient Truth won the Academy Award for best documentary, the Times ran an article by William J. Broad that again purported to represent the views of mainstream scientists on the accuracy of the film, while citing numerous scientists who are overt global warming skeptics or who have challenged fundamental facts leading to the conclusion that global warming is real and largely caused by humankind.
On May 22, 2006, Revkin wrote:
In interviews and e-mail exchanges, many climate specialists who have seen the film quibbled about details but tended to agree with Eric Steig, a University of Washington geochemist who posted his reactions at the Web log realclimate.org after a recent Seattle screening: ''The small errors don't detract from Gore's main point, which is that we in the United States have the technological and institutional ability to have a significant impact on the future trajectory of climate change.''
A June 27, 2006, Associated Press article reported a similar consensus among scientists:
The nation's top climate scientists are giving "An Inconvenient Truth," Al Gore's documentary on global warming, five stars for accuracy.
The AP contacted more than 100 top climate researchers by e-mail and phone for their opinion. Among those contacted were vocal skeptics of climate change theory. Most scientists had not seen the movie, which is in limited release, or read the book.
But those who have seen it had the same general impression: Gore conveyed the science correctly; the world is getting hotter and it is a manmade catastrophe-in-the-making caused by the burning of fossil fuels.
"Excellent," said William Schlesinger, dean of the Nicholas School of Environment and Earth Sciences at Duke University. "He got all the important material and got it right."
Robert Corell, chairman of the worldwide Arctic Climate Impact Assessment group of scientists, read the book and saw Gore give the slideshow presentation that is woven throughout the documentary.
"I sat there and I'm amazed at how thorough and accurate," Corell said. "After the presentation I said, 'Al, I'm absolutely blown away. There's a lot of details you could get wrong.' ... I could find no error."
Gore, in an interview with the AP, said he wasn't surprised "because I took a lot of care to try to make sure the science was right."
The tiny errors scientists found weren't a big deal, "far, far fewer and less significant than the shortcoming in speeches by the typical politician explaining an issue," said Michael MacCracken, who used to be in charge of the nation's global warming effects program and is now chief scientist at the Climate Institute in Washington.
By contrast, in his March 13 Times article, bearing the headline, "From a Rapt Audience, a Call to Cool the Hype," Broad wrote:
But part of his [Gore's] scientific audience is uneasy. In talks, articles and blog entries that have appeared since his film and accompanying book came out last year, these scientists argue that some of Mr. Gore's central points are exaggerated and erroneous. They are alarmed, some say, at what they call his alarmism.
Broad himself purported to accept the consensus view that global warming is at least partly anthropogenic:
Typically, the concern is not over the existence of climate change, or the idea that the human production of heat-trapping gases is partly or largely to blame for the globe's recent warming. The question is whether Mr. Gore has gone beyond the scientific evidence.
But, he then proceeded, as Media Matters noted, to cite a parade of sources who have rejected the scientific consensus to varying degrees or who have questioned, often with discredited evidence of their own, some evidence that most forcefully supports that consensus view. In support of his thesis that "[c]riticisms of Mr. Gore have come not only from conservative groups and prominent skeptics of catastrophic warming, but also from rank-and-file scientists," Broad cited numerous scientists who -- far from being "rank-and-file" scientists with "no political ax to grind" -- are well-known global warming skeptics who have made statements questioning global warming that have either been debunked or discredited by the scientific community. In some cases, Broad identified them as skeptics, but in several, he did not. Though Broad failed to say so in his article, the scientist he named specifically as his example of a "rank-and-file" scientist who has criticized the film -- Don J. Easterbrook -- has taken a position on global warming that puts him outside of the scientific mainstream and is at odds with the Intergovernmental Panel on Climate Change (IPCC). Moreover, Media Matters noted that Broad purported to expose significant flaws in Gore's work by engaging in a false comparison and by falsely suggesting that Gore endorsed the view that global warming spawns more hurricanes, which, Broad wrote, was belied by the lower-than-predicted number of named hurricanes in 2006.
Broad's article also appeared to ignore other past reports by Revkin that call into question the allegations leveled against Gore in Broad's article. As Media Matters noted, Broad used a flawed comparison to suggest that Gore's statements in An Inconvenient Truth about possible rises in sea level were an exaggeration:
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.
But in suggesting that oceans could rise 20 feet at an indefinite point in the future, Gore was specifically addressing what could happen if the West Antarctic Ice Shelf or the Greenland ice dome "broke up and slipped into the sea." The IPCC "maximum" figure of 23 inches, however, referred only to projected sea level increases based on increases in temperature by "the end of the 21st century." The IPCC also stated that "[c]ontraction of the Greenland ice sheet is projected to continue to contribute to sea level rise after 2100" and that "[i]f a negative surface mass balance were sustained for millennia, that would lead to virtually complete elimination of the Greenland ice sheet and a resulting contribution to sea level rise of about 7 m," which is equivalent to approximately 23 feet.
Moreover, as Bob Somerby noted on his Daily Howler weblog, Revkin and Elisabeth Rosenthal authored a February 2 Times article about the recently released IPCC report that Broad suggested conflicted with Gore's statements. But as Somerby noted, Revkin and Rosenthal's article actually appeared to support Gore's contentions about possible sea-level changes:
While the new report projected a modest rise in seas by 2100 -- between 7 and 23 inches -- it also concluded that seas would continue to rise, and crowded coasts retreat, for at least 1,000 years to come. By comparison, seas rose about 6 to 9 inches in the 20th century.
Should greenhouse gases continue to accumulate in the atmosphere at even a moderate pace, average temperatures by the end of the century could match those last seen 125,000 years ago, in the previous warm spell between ice ages, the report said.
At that time, the panel said, sea levels were 12 to 20 feet higher than they are now. Muych [sic] of that extra water is now trapped in the ice sheets of Greenland and Antarctica, which are eroding in some places.
The panel said there was no solid scientific understanding of how rapidly the vast stores of ice in polar regions will melt, so their estimates on new sea levels were based mainly on how much the warmed oceans will expand, and not on contributions from the melting of ice now on land.
Other scientists have recently reported evidence that the glaciers and ice sheets in the Arctic and Antarctic could flow seaward far more quickly than estimated in the past, and they have proposed that the risks to coastal areas could be much more imminent. But the I.P.C.C. is proscribed by its charter from entering into speculation, and so could not include such possible instabilities in its assessment.
Media Matters also noted that Broad included criticisms of Gore by global warming skeptics without noting errors and distortions made by those skeptics in the past. For example, while Broad included apparently critical comments by University of Alabama-Huntsville climatologist Roy Spencer, Revkin has previously written about Spencer's own errors. In an August 12, 2005, Times article, Revkin wrote:
Some scientists who question whether human-caused global warming poses a threat have long pointed to records that showed the atmosphere's lowest layer, the troposphere, had not warmed over the last two decades and had cooled in the tropics.
Now two independent studies have found errors in the complicated calculations used to generate the old temperature records, which involved stitching together data from thousands of weather balloons lofted around the world and a series of short-lived weather satellites.
A third study shows that when the errors are taken into account, the troposphere actually got warmer. Moreover, that warming trend largely agrees with the warmer surface temperatures that have been recorded and conforms to predictions in recent computer models.
The three papers were published yesterday in the online edition of the journal Science.
The scientists who developed the original troposphere temperature records from satellite data, John R. Christy and Roy W. Spencer of the University of Alabama in Huntsville, conceded yesterday that they had made a mistake but said that their revised calculations still produced a warming rate too small to be a concern.
''Our view hasn't changed,'' Dr. Christy said. ''We still have this modest warming.''
Other climate experts, however, said that the new studies were very significant, effectively resolving a puzzle that had been used by opponents of curbs on heat-trapping greenhouse gases.
In December 2006, after running a series of articles on "The Energy Challenge," The New York Times set up what it called a Reader Forum on Energy and the Environment, to which it invited readers to "weigh in" on the issue of "how the world is, and is not, moving toward a more secure, and less environmentally damaging, relationship with energy." Revkin is listed as one of four reporters contributing to that discussion. The introduction to the Readers' Forum, which notes that the "soaring" use of coal is "likely to dangerously raise temperatures and sea levels in decades to come," reads as follows:
Finding ways to supply energy for some 9 billion people by mid-century without overheating the planet or triggering oil wars is arguably a defining challenge of the times. In more than 20 articles over the past year, a team of New York Times reporters have described how the world is, and is not, moving toward a more secure, and less environmentally damaging, relationship with energy.
Now it's your turn to weigh in. Several of the project's writers, including David Barboza, Felicity Barringer, Keith Bradsher, and Andrew C. Revkin, will respond to questions and comments posted through Thursday.
The series and related graphics and photos are archived at nytimes.com/energychallenge. The articles have examined how the use of coal, the dirtiest fossil fuel, is soaring, both in the United States and in Asia, in ways that are likely to dangerously raise temperatures and sea levels in decades to come and are already wrecking landscapes and threatening air quality. Others have revealed that in many instances "biofuels," while benefiting agribusiness, may actually generate more heat-trapping greenhouse gases than conventional liquid fuels because so much energy is required to grow their raw materials. One article charted how Detroit auto manufacturers have actually been exceedingly good at squeezing ever more energy out of a tank of gasoline over the last 20 years, but have channeled the gains into more acceleration per gallon instead of miles per gallon. Another piece showed that, while there is near universal agreement on the importance of undertaking a sustained, vigorous energy quest, public and private investment into new energy options has been on a downward trajectory for many years.
Please explore the issues and post your question or comment here. The Times's writers will not be able to respond to every comment.
On October 30, 2006, Revkin wrote an article with the dire headline "Budgets Falling in Race to Fight Global Warming," in which he noted that Gore has received mild criticism for his message in An Inconvenient Truth. But the criticism is in essence not that Gore overstates the catastrophic effects of global warming, but that he is overly optimistic about existing technological capacity for addressing the crisis:
Environmental campaigners, focused on promptly establishing binding limits on emissions of heat-trapping gases, have tended to play down the need for big investments seeking energy breakthroughs. At the end of ''An Inconvenient Truth,'' former Vice President Al Gore's documentary film on climate change, he concluded: ''We already know everything we need to know to effectively address this problem.''
While applauding Mr. Gore's enthusiasm, many energy experts said this stance was counterproductive because there was no way, given global growth in energy demand, that existing technology could avert a doubling or more of atmospheric concentrations of carbon dioxide in this century.
A November 2006 post at realclimate.com, which calls itself "a commentary site on climate science by working climate scientists," argued that Broad has seriously misrepresented the science on global warming in the past. According to the post, authored by University of Chicago Geophysical Sciences professor Raymond T. Pierrehumbert, a November 7, 2006, Broad article with the headline "In Ancient Fossils, Seeds of a New Debate on Warming" "leaves the reader with the impression" that recent research on fossils undermines conclusions about the link between carbon dioxide and global warming. Pierrehumbert wrote:
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. The Phanerozoic does pose puzzles, and there's something going on there we plainly don't understand. However, the shortcomings of understanding are not of a nature as to seriously challenge the CO2-climate connection as it plays out at present and in the next few centuries.