Evidence map›Paper›PMID 42436134›Full record

ArticleNature communications2026

Efficiency-weighted cooling degree days reveal opposing temperature and humidity effects on energy demand.

Jake W Casselman, Christina Karamperidou

Abstract read
In one paragraph

Article in Nature communications, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

2 authors.

Jake W CasselmanDepartment of Atmospheric Sciences, University of Hawai'i at Mānoa, Honolulu, HI, USA. jakewc@hawaii.edu.ORCID http://orcid.org/0000-0003-2525-8422
Christina KaramperidouDepartment of Atmospheric Sciences, University of Hawai'i at Mānoa, Honolulu, HI, USA. ckaramp@hawaii.edu.ORCID http://orcid.org/0000-0001-9304-9601

Funding

National Science Foundation (NSF) AGS-2202663National Science Foundation (NSF) EEC-2330175
6 · The paper itself

Abstract

Cooling degree days (CDD) are widely used to estimate air-conditioning energy demand, yet they implicitly assume constant refrigeration efficiency, neglecting its dependence on temperature and humidity. We introduce an efficiency-aware cooling metric -effective cooling degree days (eCDD)- that links ambient temperature and humidity to the physical work required for cooling. Here we show that, across North America, cooling efficiency has declined by 2-4% per decade since 1971, and that regionally opposing trends in temperature and humidity cause CDD to misrepresent cooling demand. During hot extremes, efficiency losses are amplified under humid-heat but partially offset under dry-heat. Projections reveal a continent-scale shift in humidity regimes, with an eastward extension of dry heat that enhances cooling efficiency during extremes, while eCDD increases by 10-80%. These results demonstrate that temperature-based metrics alone are insufficient and efficiency-aware metrics are essential for accurately assessing cooling demand, especially considering differing electricity generation mixes.

Identifiers

PMID42436134
PMCPMC13483456

What OpenQuestion holds

Textmetadata
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.