Interaction between land use, climate change and the occurrence of pandemics

It is now almost universally accepted that the SARS-CoV-2 virus (virus that has caused the Covid-19 pandemic) is originally a bat virus that has spilled over to humans. In a Nature article (https://doi.org/10.1038/s41586-022-05506-2) Eby et al. have followed for 25 years, which environmental drivers are associated with the spill over of another bat virus to mammals. The study is most important, as it directly associates two big areas of environmental concern and the likelihood of bat viruses and probably also other zoonoses spilling over to humans, namely land use and climate change.

The problem with increasing land area being used by humans in increasing the likelihood of humans getting zoonoses has been suggested many times earlier. Whenever the probability of human-animal interaction increases, also the possibility of viruses spilling over to man increases. Today areas free of human influence are getting smaller and smaller because of increasing human population.

The effect of increased land use is worsened by climate change. Whenever there is drought or any other reason for food shortage, shedding of viruses to nearby organisms increases. As climate change increases drought periods, the probability of virus spill over increases. Consequently, pandemics and climate change occur together, by combatting climate change we can also prevent pandemics.