Syndemic responses to COVID-19 should include an ecological dimension.

Richard Horton argued persuasively that COVID-19 should be addressed as a syndemic of biological and social interactions. When planning the “national revival” he calls for, I consider it crucial that this syndemic approach includes an ecological dimension. Studies have found that widespread anthropogenic ecosystem degradation has played a crucial role in explaining why the rate of emergence of zoonoses has been increasing over the past 40 years. For example, deforestation, intensified agriculture and livestock production, and climate change have been linked to the emergence of Ebola virus, HIV, Nipah virus, severe acute respiratory syndrome coronavirus 2, and Zika virus.3, 4, 5

Unless reversed, the anthropogenic destruction of habitats will probably lead to the continued emergence of new zoonoses from the estimated 700 000 other unidentified viruses with zoonotic potential. As argued in the recent Living Planet Report, COVID-19 is “nature sending us a message”: we need to cut human consumption to within the planet's “safe operating space”. For the vital reasons Horton outlines, this needs to be done in a way which promotes, rather than exacerbates, national and international socioeconomic equity. National revival plans could play an important role in this process but should be subordinate to international plans that are based on determinations of both global equity and ecological constraints.