Author: Tristan Cann

Kathie and Hywel have recently published a paper exploring the level of polarization around the climate change conversation on Reddit. The full paper is available online in Environmental Communication.

Studies of climate discourse on social media platforms often find evidence of polarization, echo chambers, and misinformation. However, the literature’s overwhelming reliance on Twitter makes it difficult to understand whether these phenomena generalize across other social media platforms. Here we present the first study to examine climate change discourse on Reddit, a popular – yet understudied – locus for climate debate. This contributes to the literature through expansion of the empirical base for the study of online communication about climate change beyond Twitter. Additionally, platform architecture of Reddit differs from many social media platforms in several ways which might impact the quality of the climate debate. We investigate this through topic modeling, community detection, and analysis of sources of information on a large corpus of Reddit data from 2017. Evidence of polarization is found through the topics discussed and sources of information shared. Yet, while some communities are dominated by particular ideological viewpoints, others are more suggestive of deliberative debate. We find little evidence for the presence of polarized echo chambers in the network structure on Reddit. These findings challenge our understanding of social media discourse around climate change and suggest that platform architecture plays a key role in shaping climate debate online.

James, Rudy, Michelle and Hywel have recently published a paper exploring how different social media services can be used to detect impacts of flooding in India. The paper is available online in International Journal of Disaster Risk Reduction.

Flooding is a major hazard that is responsible for substantial damage and risks to human health worldwide. The 2018 flood event in Kerala, India, killed 433 people and displaced more than 1 million people from their homes. Accurate and timely information can help mitigate the impacts of flooding through better preparedness (e.g. forecasting of flood impacts) and situational awareness (e.g. more effective civil response and relief). However, good information on flood impacts is difficult to source; governmental records are often slow and costly to produce, while insurance claim data is commercially sensitive and does not exist for many vulnerable populations. Here we explore “social sensing” – the systematic collection and analysis of social media data to observe real-world events – as a method to locate and characterise the impacts (social, economic and other) of the 2018 Kerala Floods. Data is collected from two social media platforms, Telegram and Twitter, as well as a citizen-produced relief coordination web application, Kerala Rescue, and a government flood damage database, Rebuild Kerala. After careful filtering to retain only flood-related social media posts, content is analysed to map the extent of flood impacts and to identify different kinds of impact (e.g. requests for help, reports of medical or other issues). Maps of flood impacts derived from Telegram and Twitter both show substantial agreement with Kerala Rescue and the damage reports from Rebuild Kerala. Social media content also detects similar kinds of impact to those reported through the more structured Kerala Rescue application. Overall, the results suggest that social sensing can be an effective source of flood impact information that produces outputs in broad agreement with government sources. Furthermore, social sensing information can be produced in near real-time, whereas government records take several months to produce. This suggests that social sensing may be a useful data source to guide decisions around flood relief and emergency response.

Chris has recently published his work on tipping points in the resilience of the Amazon rainforest. Pronounced loss of Amazon rainforest resilience since the early 2000s is available now in Nature Climate Change.

Chris was also interviewed for the In the News podcast by The Irish Times. You can listen to it online.

The resilience of the Amazon rainforest to climate and land-use change is crucial for biodiversity, regional climate and the global carbon cycle. Deforestation and climate change, via increasing dry-season length and drought frequency, may already have pushed the Amazon close to a critical threshold of rainforest dieback. Here, we quantify changes of Amazon resilience by applying established indicators (for example, measuring lag-1 autocorrelation) to remotely sensed vegetation data with a focus on vegetation optical depth (1991–2016). We find that more than three-quarters of the Amazon rainforest has been losing resilience since the early 2000s, consistent with the approach to a critical transition. Resilience is being lost faster in regions with less rainfall and in parts of the rainforest that are closer to human activity. We provide direct empirical evidence that the Amazon rainforest is losing resilience, risking dieback with profound implications for biodiversity, carbon storage and climate change at a global scale.

Kathie was recently interviewed by Thomson Reuters Foundation for her expertise in online misinformation about climate change. The article was focused on what can be done to combat the spread of misinformation through social media. You can read more on the Thomson Reuters Foundation website.

I am currently doing a PhD with Prof. Ronaldo Menezes and Prof. Hywel Williams in Computer Science at the University of Exeter, UK, where I study echo chambers formation in scientific collaboration networks.

I was born in Bogotá, Colombia. I graduated with an undergraduate and master’s degree in industrial engineering at the Universidad de Los Andes in 2017 and 2019, respectively. In 2017, together with my advisors Dr Felipe Montes and Professor Olga Lucía Sarmiento, I received third place for the best undergraduate thesis in social sciences in Colombia. In 2018 I was a visiting researcher at the Health Disparities & Cultural Identities Lab of the psychology department at Florida International University. The research trip was funded by a Bridge Grant from the Young researchers of the Complex Systems Society.

A great curiosity to understand human behaviour on a social and collective level has led me to work with engineering, psychology, social sciences, education, and public health researchers. I am interested in investigating higher education systems, sociology of science, public health, and social inequity from a complex systems approach, particularly network science.