Planetary Health Research Digest
Authors: Sam Hinsley
Journal: The Lancet Planetary Health (2021)

In prevailing economies, the widespread satisfaction of basic human needs is associated with vast energy use, and thus runs up against planetary boundaries. To meet the Sustainable Development Goals, countries must fundamentally reorganise their economies towards satisfying human needs at low energy use. Jefim Vogel (University of Leeds, UK) and colleagues investigated the relationship between energy consumption and human need satisfaction, and how it varies with national socioeconomic factors. They found that none of the 106 countries studied currently meets the defined set of human needs within energy demand levels compatible with limiting global warming to 1·5°C (roughly 27 GJ per capita). Factors such as high public service quality and income equality were found to be beneficial for meeting needs at lower energy consumption levels, while extractive industries and economic growth beyond moderate affluence have a detrimental effect. Hence, improving beneficial socioeconomic factors and minimising detrimental ones could enable countries to satisfy basic needs at low energy demand. Mitigating climate change will require a combination of policy actions and individual behavioural changes. However, it is not clear whether engaging in sustainable behaviour strengthens policy support through consistency with past behaviour or weakens it through individuals feeling that they have already done their part. Gregg Sparkman (Princeton University, USA) and colleagues designed a pair of experiments to investigate this question. Compared with control participants, those who were asked to reflect on their sustainable behaviours generally did not show a reduction in support for climate mitigation policies, except for one case: support for a carbon tax declined when it was framed as having costs that fall solely on individuals (vs having costs for industry) and only if the reflection task did not relate to their values or identity (though, this effect did not clearly replicate in the second experiment). Furthermore, policy support increased if participants were asked to reflect on behaviours in a way that connected to their values and identity. These findings support the notion that campaigns to increase individual sustainable behaviour would not be harmful to broader policy approaches to mitigate climate change, and moreover can be instrumental in increasing support for such policies. Post-harvest food value chains are important components of the food system, but most analyses have been limited to the farmers (or other food producers) and consumers, the two ends of the value chain. The scale and composition of the value chain between these points is less clear. Jing Yi (Cornell University, USA) and colleagues investigated food value chains beyond the farm gate in 61 countries from 2005 to 2015 by developing a standardised data series of the share of domestic consumer food purchases received by farmers from the sale of their products. In this dataset, the average share received by farmers from food purchases for consumption at home was 27%, and this share decreases as incomes rise or when food is eaten away from home. Given that these food value chains receive the greatest share of global food expenditures, the authors argue that their environmental and workforce impacts are also likely to be sizeable and well worth future investigation. Although the environmental impacts of clothing are understood to be significant, most estimates are focused on the production phase and there is substantial uncertainty between them. Evidence on the impacts of clothing use and disposal is more scarce. Joshua Sohn (Technical University of Denmark, Denmark) and colleagues used a life cycle assessment method and consumer survey data to estimate the carbon footprints of t-shirts and jeans from production to disposal in Germany, Poland, Sweden, and the USA. Across the four countries, the average footprint of purchasing, maintaining, and disposing jeans was 70 kg CO2 equivalent per person per year and 43 kg CO2 equivalent for t-shirts. Production represented the largest share of this footprint. The use phase was highly variable between countries. While some inter-country differences stemmed from differences in power grids and efficiency of appliances, the majority came from differences in the frequency of purchases, as well as differences in the frequency of washing and drying, highlighting the importance of more sustainable behaviours in mitigating the environmental impacts of clothing.