Responsibility of Experts to Set the Record Straight

For the second time this week, a scientific article has been picked up by the mainstream press challenging the assumption that Norse settlements in Greenland were caused by the Medieval Warming Period and ended by the Little Ice Age. The first, "Cultural adaptation, compounding vulnerabilities and conjunctures in Norse Greenland," was published March 6, 2012 in PNAS. In spite of never arguing that climate change was the single driver of Viking settlement or evacuation of Greenland, the article led to the headlines:

Vikings were not spurred to Greenland by warm weather, research shows (Guardian),
Vikings’ mysterious abandonment of Greenland was not due to climate change, study suggests (Washington Post), and
Climate change didn't force Vikings to abandon Greenland, scientists say (Fox News)

Actually, the 2012 article concluded environmental changes probably
did affect Norse settlers' experience in Greenland, and thus almost certainly influenced their decision-making process. The article's conclusion put it this way:

Collectively, these environmental changes would have degraded subsistence flexibility, decreased environmental predictability, and driven threshold crossing in the marine ecosystems related to the Eastern Settlement. The small Western Settlement (with a maximum likely population of 600–800) failed sometime in the late 14th century. Although the end of the Western Settlement is not completely understood, a likely proximate cause was isolation combined with late winter subsistence failure, plausibly connected to climate change.

The main point of this 2012 article, actually, was that the Vikings were smart and resilient and that there's never a
single cause of major historical change. That seems pretty uncontroversial.


The second article, titled "
Glacial maxima in Baffin Bay during the Medieval Warm Period coeval with Norse settlement," was published Dec. 4, 2015 in Science Advances. In the abstract, the authors of this recent article say their dating of moraines on Baffin Island and western Greenland "point to nonclimatic factors as contributing to the Norse exodus from the western North Atlantic region." The article makes some interesting suggestions; among them, that temperatures varied in different parts of the North Atlantic during the Medieval Warming Period and the Little Ice Age, that warm temperatures around Iceland may have encouraged the Vikings to ship out, but they may have found it wasn't that warm when they got to western Greenland, and that the moraines they studied really didn't tell them much about ocean temperatures and ease of navigation in the North Atlantic during this period. The article suggests that the market for walrus tusks, shifts in trade and travel between Norway and Iceland, and conflicts with the Inuit may have contributed to the Vikings' decisions about maintaining a presence on Greenland. This all seems reasonable, but it's fair to wonder whether some of these changes might not have been influenced by climate? Could harsher conditions in the interior and northern coast of western Greenland have brought Inuits into closer contact and conflict with the Norse settlements at this time? The article's authors never claim to have found the final, single answer to this mystery. But will that prevent their study from becoming the basis of a new series of "it wasn't climate change" stories in the mainstream media?

The first mainstream article I've seen based on this new study is from
Smithsonian, dated December 4, 2015. Although it's a pretty balanced article, Smithsonian couldn't resist the temptation to title it "Did Climate Change Make the Norse Disappear from Greenland?" The article is interesting, includes several useful links, and concludes that even if scientists embrace this new data, it's still reasonable to say "climate change is very much part of the mix." But based on the comments following the article, the subtleties are falling to the wayside. Like the previous newspaper articles, this is also being understood as part of the current debate about whether climate change is real. I suspect if other news outlets report on this story, their stories will be less balanced than Smithsonian's and more like those I mentioned above.

So my question is, do scientists and other professionals (like Environmental Historians) have any responsibility for how their work is used? Presumably the authors of these studies, who discussed the complexity of the issue and the lack of monocausal explanations, do not support the use of their work to confuse the public regarding climate change. The authors of the 2012 article may even be surprised that three years after its publication, their article has become the basis of this raft of stories (timed to precede the new publication?). If I had written that article, I'd be shaking my head with frustration about now, muttering "but that's
not what we said."

If I had written that initial article, I'd be a little dismayed that my work was being used in major newspapers (and the myriad of smaller papers and blogs that pick up this story) to confuse readers regarding the influence of climate on human societies. I'd be writing letters to the editors of those papers. I'd be tweeting about it, trying to set the record straight. Given that the initial motivation for their research was probably to help set the record straight about the complex nature of historical change, I've got to imagine these scientists would like everybody to understand that point, not just their professional peers.

A final thought, and I apologize if this seems cranky, but I've noticed a lot of historians and even EnvHist folks have retweeted these mainstream articles without comment. In spite of the convention that "RT=/ Endorsement," I think when a large number of historians' feeds start presenting these news reports without any qualification, they're furthering someone else's agenda.