Friday, Jul 24, 2026 The claims desk. Receipts included. POWERED BY LENZ ↗
IsThis

HEALTH

The Claim

The amount of sleep loss caused by high temperatures that is attributable to climate change has at least doubled since the early 1970s.

Verified by Lenz ·

The Short Version

Available evidence supports the claim: modeled climate-attributable heat-related sleep loss rose from roughly 2 hours per person per year in the early 1970s to about 5 hours in 2020-2025, which is more than a doubling. The main caveat is that this exact doubling estimate comes primarily from one attribution analysis rather than multiple independent replications.

Caveats

  • The exact 'at least doubled' figure is driven mainly by one Climate Central modeling analysis, not several independent peer-reviewed attribution studies.
  • The underlying sleep effect of hotter nights is well supported, but the climate-change-attributable portion depends on model assumptions and counterfactual temperature estimates.
  • The absolute increase is small in annual average terms; the finding is about a relative doubling of attributable sleep loss, not a doubling of all sleep loss overall.

The Receipts

  1. Hot nights are stealing people's sleep, researchers say

    Euronews

  2. A systematic review of ambient heat and sleep in a warming climate

    PubMed

  3. 56 hours of sleep lost per year as warming nights double ...

    upday

  4. Climate warming may undermine sleep duration and quality in repeated-measure study of 23 million records

    Nature

  5. Impacts of heat on sleep quality among heat-exposed workers

    PMC

  6. Climate warming may undermine sleep duration and quality in repeated-measure study of 23 million records

    PMC

  7. Climate Change is Costing People Sleep

    Climate Central

  8. A systematic review of ambient heat and sleep in a warming climate

    medRxiv

  9. Climate change likely to reduce the amount of sleep that people get

    ScienceDaily

  10. Nighttime temperature and human sleep loss in a changing climate

    Proceedings of the National Academy of Sciences (via NCBI PMC)

+ 12 more sources — see the full list on Lenz

Filed Under

climate change

More Fact Checks