Planetary health research digest
Authors: Sam Hinsley
Journal: The Lancet Planetary Health (2019)

Development within the Amazon rainforest is a contentious topic, and one that has received renewed focus since the election of Jair Bolsonaro as President of Brazil. While much attention has been given to the destruction of the rainforest due to unchecked development, the framing of the discussion has largely been in terms of the long-term impacts on carbon storage and biodiversity this will have at the global level. Marcia Castro (Harvard T H Chan School of Public Health, USA) and co-authors instead look at the local and immediate effects of unsustainable development in the Brazilian Amazon on vector-borne diseases. They find that the creation of habitats suitable for mosquito vectors was one of the major drivers, leading to the spread of diseases such as malaria, dengue, Zika, and chikungunya in poorly planned urban environments and recently deforested areas. Castro and colleagues call for greater coordination of existing disease surveillance mechanisms, greater consideration of planned development at the regional level (including across borders), and revisiting current austerity measures to focus on reducing inequalities as potential ways to mitigate these harmful effects of development. Consumer preference has been identified as a powerful tool in the shift to more sustainable diets, and food labelling is a relatively simple measure to affect this preference. However, most research on food labelling has been on health and nutrition labelling, with less work on sustainability-related labelling. Rebecca Tobi (London School of Hygiene & Tropical Medicine, UK) and co-authors conducted a systematic review of studies on consumer preferences for nutrition labels against those providing environmental and social responsibility (eg, animal welfare or fair trade) details. The social and environmental label attributes were favoured in 17 of 30 studies identified, and combinations of attributes were valued more highly than attributes in isolation. Notably, labels stating that products were organic were the preferred type of environmental label, likely due to assumptions about the healthiness of such products. While labelling can help to guide consumers towards more sustainable choices, care must be taken not to relieve manufacturers and governments of their responsibilities in making these choices as easy and fair as possible. Heatwaves are one of the most readily apparent impacts of climate change, and can severely harm human health, food systems, and ecosystems. Understanding the processes that underlie these events is crucial for predicting them, as well as how the will be affected by a changing climate. Kathrin Wehrli (Institute for Atmospheric and Climate Science, Switzerland) and co-authors used the Community Earth System Model to analyse five heatwaves from 2010 to 2016. They looked at the relative contributions of several factors to these events, namely greenhouse gas forcing, land surface (ie, soil moisture), atmospheric circulation, and ocean conditions. Among the five heatwaves studied, the roles of atmospheric circulation and soil moisture were consistently the largest, and events were amplified by recent climate change. Anomalous declines in soil moisture were identified in the months preceding four of the five heatwaves, indicating that preconditioning of soil moisture is an important factor for modelling heatwaves. This, the authors highlight, could be a challenge as land surface models for weather prediction typically receive less attention than their atmospheric counterparts. The publication of the IPCC's special report Global Warming of 1·5°C in October, 2018, was a major event within the climate change community, but its effect on the wider public perception of climate change is less well understood. Charles Ogunbode (University of Bergen, Norway) and colleagues used data from representative surveys of the Norwegian population to investigate whether exposure to the report was associated with people's perceptions of the threat of climate change and how these perceptions changed before and after its release. They find that concern about climate change generally increased after the report was published, and that the increase in concern was greatest among those people who reported exposure to the report. When analysed by political orientation, the increase in concern was greatest among people who identified with the political left, and declined as political beliefs moved towards the right, eventually becoming non-significant at the far right of the spectrum. While the findings reflect the polarisation associated with the issue, the authors conclude that reports such as this can still have an important role in promoting engagement and action on climate change.