We Fact-Checked a Bogus "Study" on Global Temperature That's Misleading Readers

July 21, 2017 | 4:38 pm
Brenda Ekwurzel
Senior Climate Scientist, Director of Climate Science

Independent peer-review of scientific research by qualified experts lies at the heart of progress in our understanding of how the natural world works. And posting proposed new scientific findings on the internet without peer-review can lead to some wildly incorrect conclusions being promoted as true.

Consider, for example, the document posted on the internet last month by James Wallace III, Joseph D’Aleo and Craig Idso.

In On the Validity of NOAA, NASA and Hadley CRU Global Average Surface Temperature Data, the authors purport to show flaws in the major adjusted global datasets used to track the recent historic increases in Earth’s global average surface temperature arguing that “it is impossible to conclude from the three published GAST data sets that recent years have been the warmest ever –despite current claims of record setting warming.”

Wallace, D’Aleo and Idso offer up to the internet a document that points almost exclusively to dataset sources, ignoring virtually all peer-reviewed studies that examine the issues that they raise.

The authors also take several graphs out of context in an attempt to discredit these well-regarded global average surface temperature datasets that have been assiduously reviewed by multiple independent teams of technical experts and consistently found to be robust.

Normally, it is best to avoid overreacting to unsubstantiated claims about science posted on the internet.

But these are not normal times.

Leading officials of the Trump administration are making false claims about climate science and solutions and using cherry-picked “evidence” to justify their efforts to undermine climate policy.

I asked Rachel Licker, UCS senior climate scientist, to offer a technical review.  Here’s what she wrote:

There were so many egregious errors and unsubstantiated claims in this document, that I cringed with discomfort that this could be mistaken as a peer-reviewed scientific study.

Licker offered a few examples of these errors that taken out of context could be confusing:

Embarrassing Error # 1:

The authors erroneously claim that the NASANOAA, and Hadley CRU global average surface temperature records all produce the same results simply because they use many of the same land-based weather stations as sources. 

These datasets incorporate information from thousands of individual weather stations, ocean measurements and satellite data. Each of these datasets incorporate as many high-quality temperature data sources as possible, including many in common.  Then, each dataset is constructed and analyzed using different methods. Why? Because this is what scientists do to be confident about their results. Scientists test and re-test datasets to see if – using different methods and approaches – they get the same results as their colleagues working independently. I would not want to fly in a plane that had only been inspected once – would you?

Embarrassing Error # 2:

The authors falsely claim that the NASA, NOAA and Hadley CRU GAST records do not properly take into account factors such as urban heat islands and changes in the technologies used to measure land and ocean temperatures over time. They also falsely claim that each of the datasets has selectively biased results in order to exaggerate an upward trend in temperature.

In fact, it is well-established that these datasets do account for these and other factors needed to ensure consistent, comparable and accurate results. Researchers have repeatedly found that the methods used to account for these issues do not affect GAST records to any substantial extent. The size of global surface temperature increases swamps the noise associated with these known and well-studied factors.

Embarrassing Error #3:

The authors cherry-pick some examples in the US as “evidence” that they use to try and refute the well-documented increase in the global average temperature.

Of course, the NOAA, NASA, and CRU datasets include these regional variations. Bottom line: there is a pronounced increase in the global average surface temperature since pre-industrial times and such regional variations are to be expected.

Global Average Surface Temperature (GAST) trend between 1880-2016, annual record. Temperature change is reported relative to the long-term annual average (1910-2000). Source: NOAA

The near-complete lack of references to other scientific studies that examine their spurious claims and the extent to which the authors of this document take information out of context is, quite frankly, embarrassing.

Elected officials have a responsibility to reject such poor quality work, and instead rely on their own cornerstone institutions like the National Academy of Sciences, established by Abraham Lincoln and Congress in 1863, to provide “independent, objective advice to the nation on matters related to science and technology.”

As Ben Santer and colleagues pointed out in a recent Washington Post op-ed, “Only the most robust findings survive peer review and form the basis of today’s scientific consensus.” The peer review process exists to prevent such documents as the one at hand here from making their way into the public domain and being confused with real science.