An assistant professor of geochemistry at Syracuse University is the latest victim of the echo chamber of climate change denial which is used to mislead the public about the results of academic research.
On 21 March, Syracuse University issued a media release to draw attention to a new paper by Dr Zunli Lu and co-authors, which was published online in the journal Earth and Planetary Science Letters on 25 February.
The paper, 'An ikaite record of late Holocene climate at the Antarctic Peninsula', described the discovery of crystals of a rare mineral form of calcium carbonate, which decomposes at temperatures above 4°C, in sediments from a drilling site. By dating the occurrence of ikaite in the drilling core, the authors concluded that it "qualitatively supports that both the Medieval Warm Period and the Little Ice Age extended to the Antarctic Peninsula".
These conclusions are interesting because relatively little evidence has been found that the 'Medieval Warm Period' (MWP), between about 950 and 1100 AD, and the 'Little Ice Age' (LIA) in the 17th century, extended beyond the northern hemisphere.
The paper stated: "The resolution of our record is insufficient to constrain the ages of these climatic oscillations in the Southern hemisphere relative to their expression in the Northern hemisphere, but our ikaite record builds the case that the oscillations of the MWP and LIA are global in their extent and their impact reaches as far South as the Antarctic Peninsula, while prior studies in the AP [Antarctic Peninsula] region have had mixed results".
The researchers also suggested that their results indicated "a warming relative to the LIA in the last century, possibly as part of the regional recent rapid warming, but this climatic signature is not yet as extreme in nature as the MWP". However, the paper did not include any comment on the cause of recent warming in the Antarctic Peninsula and the rest of the world.
The university's media release, headed 'Scientists use a rare mineral to correlate past climate events in Europe and Antarctic', whilst providing an accurate summary of the paper, suggested, somewhat tenuously, that the research might help to cast light on recent weather events in the United States, but did not explicitly mention global warming.
Despite the media release, the research received no mainstream media coverage. But it was picked up by the climate change 'sceptic' website 'Watts Up With That', operated by former TV and radio weatherman Anthony Watts. Its coverage of the paper on 22 March offered a rather more certain headline of 'More evidence the Medieval Warm Period was global'.
Many climate change 'sceptics', including Anthony Watts, are obsessed with the Medieval Warm Period. They believe that if irrefutable evidence can be found that the warm period in the northern hemisphere about 1,000 years ago can be shown to have occurred across the world, it will prove that the recent rise in global average temperature over the past few decades cannot be attributed to greenhouse gas emissions from human activities such as burning fossil fuels.
This is, of course, an intellectually feeble line of reasoning. Just because the Earth has experienced previous warming periods due to 'natural factors', such as oscillations in the Earth's orbit around the Sun, that does not mean that the current period of warming must also be natural. It is the equivalent of arguing that humans are not responsible for the recent increase in loss of animal and plant species on Earth because previous extinction events were caused by 'natural' factors, such as meteorite impacts.
Attempts to attribute recent global warming to 'natural' factors, such as changes in the Sun's activity or variations in cosmic rays from outer space, have failed to yield any substantial supporting evidence. By contrast, the evidence grows ever stronger that the indisputable increase in atmospheric levels of greenhouse gases since the 18th century is primarily responsible for the unequivocal warming of the Earth over the past few decades.
Nevertheless, 'sceptics' continue to promote the myth that if the Medieval Warm Period was global 3,000 years ago, then greenhouse gas emissions cannot be the cause of recent global warming.
So the article on 'Watts Up With That' was seized upon by other 'sceptics, who repeated and distorted it.
First, The Register, a British website aimed at the information technology industry which regularly features inaccurate and misleading articles about climate change which it has scavenged from 'sceptic' websites such as 'Watts Up With That', covered the story on 23 March, under the headline 'Medieval warming WAS global - new science contradicts IPCC'.
The article, which reporter Lewis Page apparently based on the university media release and the coverage on 'Watts Up With That', offered an even more extreme interpretation of the significance of the new research as a refutation of the conclusions of the Intergovernmental Panel on Climate Change (IPCC). The article in The Register stated:
"The IPCC consensus is that the medieval warming - and the 'Little Ice Age' which followed it - only happened in Europe and maybe some other northern areas. They were local events only, and globally the world was cooler than it is now. The temperature increase seen in the latter half of the 20th century is a new thing caused by humanity's carbon emissions."
The article ended with the following summary of Dr Lu's research: "In other words, global warming has already occurred in historical, pre-industrial times, and then gone away again".
This article then bounced into the offices of the Daily Mail, a UK newspaper which has been energetically promoting unscientific views about climate change ever since its editor, Paul Dacre, was lobbied over lunch by Nigel Lawson, the chair of the 'sceptic' campaign group, the Global Warming Policy Foundation.
On 26 March, Ted Thornhill, sent an e-mail to Judy Holmes at the press office of Syracuse University, asking: "Just writing up the Ikaite story for the Daily Mail's website - so would Professor Lu agree with the conclusions draw [sic] in The Register, that global warming in fact isn't man made, that it's just something that occurs anyway?"
Ms Holmes replied: "I highly doubt that the conclusions reached by some of the 'global warming' deniers is what Professor Zunli Lu had in mind when he published his paper". She suggested that Mr Thornhill seek a reply directly from Dr Lu.
But Mr Thornhill decided not to wait for Dr Lu to comment and instead published his article on the website of the Daily Mail under the headline 'Is this finally proof we're NOT causing global warming?'
The opening paragraph of Mr Thornhill's story, which drew heavily, but without attribution, on the article in The Register, stated: "Current theories of the causes and impact of global warming have been thrown into question by a new study which shows that during medieval times areas as far apart as Europe and Antarctica both warmed up".
Dr Lu was understandably unhappy about the misrepresentation of his work by the Daily Mail. Syracuse University posted on the home page of its website a statement of rebuttal, including the following quote from Dr Lu: "It is unfortunate that my research, 'An ikaite record of late Holocene climate at the Antarctic Peninsula', recently published in Earth and Planetary Science Letters, has been misrepresented by a number of media outlets".
The statement ended: "Our study does not question the well-established anthropogenic warming trend".
However, other 'sceptics' ignored Dr Lu's statement and instead continued to propagate the misrepresentation of his work, with the Global Warming Policy Foundation reproducing on its website the articles from the Daily Mail and The Register. And Fox News re-wrote the article from the Daily Mail for its website on 1 April under the headline 'Study Refutes Manmade Warming'.
This episode demonstrates once again the way in which 'sceptics' and their champions in the media use the amplifying and distorting echo chamber of climate change denial to shamelessly misrepresent the work of researchers.
Bob Ward is policy and communications director at the Grantham Research Institute on Climate Change and the Environment at London School of Economics and Political Science.Suggest a correction