Polemics and Controversies as Catalyst for Science Communication and Source of Local Knowledge

Abstract

Decisions in environmental management often ignite debates. Occasionally, these debates escalate into polemics (i.e., intense disputes characterized by strong disagreements and opposing viewpoints) from the community to the authorities, particularly when tied to actions at the local scale. Despite the potential discomfort associated with polemics, they can still serve as a valuable source of local knowledge for researchers working in various fields of environmental science. Indeed, while polemics can sometimes distort reality, they emanate from the firsthand experiences, or perceptions, of individuals witnessing the consequences of management actions on the territory. The media take care of amplifying these controversies, offering a second great opportunity for researchers: leveraging the resonance of these discussions to enhance the communication of scientifically sound information.

An illustrative case is the recent controversy surrounding the opening of the Adige-Garda diversion tunnel in Italy during the Ciarán storm, on 31 October 2023. The 10-km-long tunnel is a crucial civil protection hydraulic structure completed in 1959 that connects the Adige River to Lake Garda (Fig. 1). Its primary purpose is to mitigate the risk of flooding in Verona by diverting excess water into the lake during significant floods (the tunnel has been opened a dozen times since its completion). Although debates often heat up after openings, the recent opening has sparked a more intense discussion about the tunnel's role in transporting wood debris and turbid water into the lake (as well as about the timing of the opening, but that is another story).

However, it is important to clarify an important aspect that may not be known by everyone, otherwise there would not have been a debate about it: wood debris does not come from the tunnel. The spillway is equipped with a grid upstream of the Adige River intake and operates through four sluice gates (Fig. 1c): water flows under the gates and any wood debris not retained by the upstream grid would accumulate upstream of these gates. Instead, the wood and floating debris comes mainly from the lake's tributaries, in particular the Sarca River (the main tributary of Lake Garda), which is closely monitored during such events by the Riva del Garda Volunteer Fire Brigade, which uses containment nets to catch the transported wood once it reaches Lake Garda (Fig. 1a).

The plot in Fig. 2a shows the time series of discharges into the lake from the Sarca River (solid blue line) and the Adige-Garda diversion tunnel (dashed blue line) between 30 October and 4 November. The corresponding cumulative volumes delivered to the lake are shown on the right axis (solid and dashed red lines, respectively). At the time the tunnel was closed (around midnight on 1 November), the spillway discharged about 3.6 million m³ into the lake, corresponding to 18.7% of the volume discharged by the Sarca River since the beginning of the flood event. This percentage dropped to about 10% at the beginning of the declining phase of the second flood, which occurred on 4 November when the Sarca River was still discharging turbid water into the lake (Fig. 2b).

The satellite image from 4 November shown in Fig. 2b highlights the persistent turbidity in the Sarca River, generating a noticeable plume in the lake. The image also shows the accumulation of turbid water along the western coast, which partly explains why the criticism of the tunnel openings, along with a municipal inquiry, came mainly from the Brescian coast, as documented in numerous articles in local newspapers (see, e.g., the articles, in Italian, published in Corriere della Sera—Brescia, https://brescia.corriere.it/notizie/cronaca/23_novembre_10/le-spiagge-del-garda-invase-da-legno-e-spazzatura-arrivate-dall-adige-adesso-chi-pulisce-bd59c8f2-f931-4500-867f-cc5a7582cxlk.shtml?refresh_ce, and GardaPost, https://www.gardapost.it/2023/11/10/lo-scolmatore-ha-riempito-le-spiagge-di-legname-ora-chi-paga-la-pulizia/). This is a fascinating aspect. Indeed, it is rooted in a physical explanation recently demonstrated by Piccolroaz et al. (2019), combining in situ monitoring data and modeling: despite the narrow shape of Lake Garda (about 2–3 km width in the northern part), Earth's rotation plays a key role in generating secondary circulations to the right of the wind, just as happens in larger lakes and in the ocean. This is also consistent with local knowledge reports, narratives and anecdotes from recent surveys open to lake users, even those respondents were not consciously aware of the existence of this phenomenon (Amadori et al. 2020). During the considered storm event, the persistent northerly winds across the lake (see the inset in Fig. 2b) favored the transport of turbid waters and wood debris toward the south-western Brescian shore (i.e., to the right of the wind) and the upwelling of clean waters along the eastern shore. This pattern fits perfectly with the geographical source of the discontent, which can be seen as an additional layer of local knowledge that enriches our understanding of transport phenomena in the lake. This is a confirmation that local knowledge can be a valuable source of qualitative information, especially in cases where a lack of scientific knowledge and/or monitoring is offset by a significant presence of the local community (Schlacher et al. 2010; Amadori et al. 2020). The incorporation of this type of soft information into scientific research is undoubtedly appropriate and well possible in the big data era we now live in.

This specific case also led me to think that, in a broader sense, polemics and controversies in environmental management can be turned into an opportunity, as they can be seen as a potential catalyst for science communication. I propose that scientists should use their independence and impartiality to leverage the attention that is often drawn to public controversies to improve the communication of scientifically and technically sound information, with the aim of increasing citizens' knowledge and addressing potential misrepresentations of reality. Today, this may not be too difficult, given the wealth of social media available and widely used by scientists to communicate their findings and thoughts. This is certainly true for large institutions that can count on professional communicators, but also for smaller research groups, as evidenced by the inspiring Arctic science communication initiative of the Norwegian Polar Institute (Pavlov et al. 2018). In addition, press releases and letters to local newspapers reporting on ongoing debates are effective ways of capitalizing on media resonance and extending outreach to a wider audience. Of course, it takes time to develop a robust and easy-to-understand position based on trustworthy data and scientific reasoning, and by the time it is ready, the media momentum may have waned. In some cases, however, debates on an issue remain evergreen and opinions on the matter retain both relevance and interest. In such instances, direct engagement with the public through local events is an outreach activity that research institutions should strongly endorse and scientists should actively pursue.

As a personal initiative, I have communicated the above considerations on the opening of the Adige-Garda tunnel via my personal social media accounts (https://www.linkedin.com/in/sebastianopiccolroaz/ and https://twitter.com/SPiccolroaz), which have attracted considerable attention with 11,874 impressions, 160 likes and 8 reposts on LinkedIn (last report on 15 January 2024; the post, Italian, is accessible at this link: https://www.linkedin.com/feed/update/urn:li:activity:7129235752617426945/). A recent remote sensing study has been published on this subject (Ghirardi et al. 2020) and an M.Sc. thesis in Environmental Engineering at the University of Trento is currently focusing on the fate of the Adige-Garda plume in the lake, using a combination of three-dimensional hydrodynamic modeling and in situ measurements. It is hoped that this will be a step forward in the investigation but also public communication of this case study, providing relevant and reliable information on the impact of the diversion tunnel on the lake and improving the management of periodic maintenance openings. There is a high level of interest in this topic from the local community, and the issue is environmentally relevant and scientifically interesting. Future research should focus on quantifying the fluxes of nutrients, pollutants, and biological matter through the Adige-Garda diversion tunnel and on distinguishing them from the fluxes originating from the natural inflows. This is an aspect that attracts the attention of local people and fishermen and provides an exciting opportunity to integrate local knowledge and scientific understanding through future collaborative efforts between researchers and the community.

In conclusion, I argue that overcoming the contentious nature and discomfort of the polemics that sometimes surround environmental management decisions and harnessing the attention they receive from the media can be turned into an opportunity for researchers. This provides a platform to improve the communication of science-based information and increase the knowledge of citizens. It can also attract the interest of local governments and encourage them to allocate funds to research initiatives, possibly creating win-win situations to promote better knowledge, communication, and protection of natural resources.