Quantifying the human cost of global warming

Abstract The costs of climate change are often estimated in monetary terms, but this raises ethical issues. Here we express them in terms of numbers of people left outside the ‘human climate niche’—defined as the historically highly conserved distribution of relative human population density with respect to mean annual temperature. We show that climate change has already put ~9% of people (>600 million) outside this niche. By end-of-century (2080–2100), current policies leading to around 2.7 °C global warming could leave one-third (22–39%) of people outside the niche. Reducing global warming from 2.7 to 1.5 °C results in a ~5-fold decrease in the population exposed to unprecedented heat (mean annual…

• OS
  Open Society Foundations

  Award: OR2021-82956
• GA
  Gordon and Betty Moore Foundation
• VF
  Villum Fonden

  Award: 16549
• GE
  Global Environment Facility
• PF
  Porticus Foundation
• NN
  National Natural Science Foundation of China

  Awards: 32061143014, 16549
• FR
  Fundamental Research Funds for the Central Universities