Evaluating the impact of climate communication activities by scientists: What is known and necessary?

This manuscript reports on original research conducted by the authors. The aim, study design and results are communicated with excellent clarity. It makes a much-needed contribution to the field of science communication by evaluating the impact of climate communication activities by scientists on ordinary people’s behaviour of which there is limited knowledge, as the study finds.

The title is clear and aptly describes the content of the manuscript. The abstract provides a short and clear summary of the important findings and conclusions? The introduction provides a good summary of literature on the topic with well-defined aim and research question. The framework for evaluating science communication activities is identified along with the three communication models used by scientists. The authors may like to include examples of when each of these models may have been used effectively. For example, there is a place for the deficit model in disaster risk communication in the aftermath of disasters, but dialogue and participatory approaches may be more effective in designing effective risk communication strategies with communities.

The method for literature survey is well explained. Did the researchers consider using participatory and dialogue as climate change communication search terms since these methods are considered to be more effective in bringing about behaviour change?

I would suggest that authors include the description of the included studies as a table within the text instead of as Appendix A. The discussion highlights some important findings including the need to include both negative and positive impacts of communication activities.

The authors may like to suggest the importance of interdisciplinary studies where scientists and communication researchers can work collaboratively to understand impact of communication activities especially using dialogue and participatory models.

Overall, this manuscript is very well written and offers an important insight into an area which is in need of further exploration.

I will start by saying that this review was very insightful. I’m both surprised and disappointed by the lack of literature regarding this subject and I agree that this should be better understood and studied, as I work everyday with climate scientists to help them better communicate.

Here are some comments. I hope this can help you improve your paper.

• I suggest that you dig a little deeper into the literature about scientists as communicators in general, not just in the field of climate science. I know that there is a lot of literature that delves into this more general issue.
• For instance, in Section 1.1, it is mentioned that research shows that scientists are seen by the public as trusted information producers and that they should increase their communication efforts, which is true, but a limited description of scientists as communicators. This positive aspect about scientists can sometimes be counterbalanced by recurring shortcomings such as the difficulty in simplifying scientific information or the sense of inferiority that non-scientific target audiences may feel towards them. Additionally, scientists generally lack the necessary skills and tools to communicate effectively based on their target audience, just because they weren’t trained to do so.
• These observations about scientists, in general, could also be discussed in section 5, where it is mentioned that care should be taken in concluding that climate communication activities by scientists have a positive impact.
• The emergence of "knowledge brokers" in the last decade is something worth exploring to enhance scientific communication. These brokers are particularly present in various health science fields. They may or may not be scientists, but they possess the technical skills to communicate science and engage their audience while maintaining scientific rigor. They are an important tool to scientists who need to communicate. https://journals.sagepub.com/doi/abs/10.1177/1075547009359797
• This brings me to suggest to add some words about who are the main climate communicators. Except for scientists, who else is talking about climate change and what can we say about them (these include knowledge brokers).
• Along these lines, in Section 2.2 : You mention “scientists” and “science communicators” which for me, are very different source of information with different sets of skills and different impacts on the target publics. I get that these two types are described in the dialogue model, but when you read the paper it feels like these two are the same. If you have better presented the different communicators somewhere between the introduction and the theoretical framework, it will be less confusing.
• I feel like the fundamental goal of the review, or what the conclusions will lead to, could be more specific. For instance, if there are so few research papers on this subject what should we do about it? If the deeper goal is to have effective communications that reach as many people as possible and have the greatest impact on their engagement in the climate change crisis, regardless of the communicator's status, I believe one of the main conclusions should be the need to explore the possibilities offered by knowledge broker or other types of communicators in collaborating with climate scientists.
• Helping climate scientists become better communicators is also a worthwhile goal but very different to me. Both could be discussed in the paper. https://link.springer.com/chapter/10.1007/978-3-319-50398-1_22
• Training for professionals, outside the academic setting, is an important part of climate change communication activities, but there is little evidence of its effectiveness in changing perceptions and behavior. This type of communication is perhaps more often associated with scientists and could be interesting to explore in future research. « Il n’existe aucune preuve de l’impact d’une formation de sensibilisation aux enjeux climatiques sur les comportements » (lemonde.fr)
• Section 4.2: The audiences accessing climate information could be something better documented in other types of papers who might have been excluded from your review because of your methodological choices. I’d end this section by opening on what we could find elsewhere on this matter, like the fact that these conclusions can vary greatly across the world. For example, here in Canada, scientists and climate communicators are aiming to a very large public as a lot of them are government employees who have the “mandate” to inform practitioners and the population in general, about climate mitigation and adaptation. But this couldn’t be more false in other countries.
• Finally, it might be interesting to add a few words about the different target audiences for climate change-related information and their levels of knowledge and engagement. This would help support the argument presented in section 1, line 25. https://www.nber.org/system/files/working_papers/w30265/w30265.pdf 
• In the conclusions, you talk a lot about communication frameworks (which is ok, because it is what you chose to research about) but you could also suggest more research on tools that could help climate scientists to communicate. One important tool is to clearly define the target audience. For example, this survey is prepared each year by a marketing communication research lab in Laval university in Quebec, Canada. It is a tool to help Quebec’s climate communicators get to know their audience better and prepare their interventions (french paper). https://unpointcinq.ca/wp-content/uploads/2023/11/Barometre-Action-Climatique-2023.pdf