Evidence-based communication on climate change and health: Testing videos, text, and maps on climate change and Lyme disease in Manitoba, Canada

group, someone declared that the article was “propaganda,” and in another someone noticed that amongst the peer-reviewed literature there were also news articles and grey literature cited, and said that the article was not credible because of its sources. Among those in the high climate concern groups, some people wanted more information on the implications of the connection between action on climate change and Lyme disease. As one participant in Winni- peg stated: “Do you think reducing emissions–which I agree is needed and a must–do you think it’s going to change anything about Lyme disease? Even if we stop producing any emis- sions tomorrow, [the ticks] are here.” Video. Many participants across groups reported enjoying the video and finding it engag- ing. A key message identified was that blacklegged ticks and Lyme disease are not abating and thus people must learn to adapt and take preventative measures. Other key information reported was how Lyme disease is spreading, how ticks survive in warmer weather, and the increasing risk in Manitoba. As one Winnipeg participant described their key takeaway: “Lyme disease is growing a lot faster than I thought. It’s going to become more and more of a threat.” People found the visuals particularly helpful, such as the images of the bullseye rash common after a tick bite, the blacklegged ticks themselves, and researchers sampling for ticks in suitable habitat. People in several groups also commented that they liked the story element; as one Brandon participant described, “It was good how they went from. . . a personal story

and then kind of backing it up with some of the research.” The preferred messengers from the video were the community member who had contracted Lyme disease, the medical doctor who actively sees Lyme patients, and the field researcher who sampled ticks, as opposed to the scientists in labs and offices. People in four groups reported having more of an emotional reaction to the video, while one participant said the video had a more positive valence and “wasn’t as much doom and gloom.” When asked whether the video was about Lyme disease, climate change or both, gen- erally the consensus was that it was more about Lyme disease. Only one group had several peo- ple comment on the link between the spreading of Lyme disease and climate change. Many of the same skeptical critiques were brought up for the video as with the article amongst the three low climate concern groups. Many people across all three groups mentioned that there was not sufficient proof that the tick spread was related to climate change, though people were not able to articulate the additional information they would require. Many people restated their original views, saying things such as “animals are just moving,” “the weather hasn’t changed that much” or “it is a cycle.” A few people admitted that they would not watch the video if they came across it because they did not find it interesting or informative. Maps. Participants had a more negative reaction to the maps overall. Across all six groups, people identified the key message of the maps was that temperatures are getting warmer and

things are going to get worse. Some people pointed out that this will lead to an increase in the spread of ticks and Lyme disease, but for many that was not immediately clear. Generally, peo- ple agreed that the main message of the map was that climate change is getting worse, while several said it was the link between climate change and Lyme disease. People in several groups commented on the intensity of the red colouring, with one participant commenting, “When you make the province of Manitoba look like it’s wearing a Calgary Flames [hockey] jersey, it looks scary.” There were many criticisms of the maps, with people in every group saying that the lan- guage used in the map caption was too complex and technical for an average person. Partici- pants expressed not understanding climate models and projections, degree days, high carbon emissions scenarios (RCP 8.5), and down-scaled climate data. Another point of confusion was the timeframes of the past, near future, and far future used on the maps; many people in five of the groups wanted to see the present represented (i.e. 2019). People in two of the groups PLOS ONE Evidence-based communication on climate change and health PLOS ONE | https://doi.org/10.1371/journal.pone.0252952 June 10, 2021 6 / 17