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Understanding variability and trends in the near‐surface diurnal air temperature range (DTR) remains unclear due to its complex interactions with antecedent radiative and hydrologic conditions. Here, we use a thermodynamic systems approach, and show that DTR primarily reflects changes in lower atmospheric heat storage, governed by diurnally constrained non‐latent energy input from the surface into the atmospheric boundary layer. This approach predicts DTR across a range of climates, reproduces its day‐to‐day variations, and explains its decline with rising greenhouse gas (GHG) concentrations. We show that in addition to strong controls exerted by radiation and cloud cover, DTR carries imprints of surface water stress during the water‐limited evaporative regime. Our expression yields a mean reduction of 0.23°C in DTR per 1°C rise in temperatures, in response to changes in GHG forcings. Our findings imply that the first‐order decline in DTR with global warming can be explained by increased GHG forcings alone.
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This content will become publicly available on November 29, 2026
Climate change has increased global evaporative demand except in South Asia
Climate change alters how strongly the atmosphere draws water from the land, yet a consistent global assessment of this evaporative demand has been lacking. Here, we analyze 45 years of climate data and global models to quantify trends in the key drivers—air temperature, humidity, radiation, wind speed, and cloud cover—that determine the atmosphere’s drying power. We find that evaporative demand has increased worldwide, indicating a stronger atmospheric thirst, except in South Asia, where it has declined. There, widespread irrigation has increased soil and air moisture, enhanced cloud formation, and reduced sunlight reaching the surface, counteracting the global signal. These contrasting trends reveal how human water use can locally reshape the climate’s influence on the water cycle.
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- Award ID(s):
- 2012893
- PAR ID:
- 10708782
- Publisher / Repository:
- Nature
- Date Published:
- Journal Name:
- Communications Earth & Environment
- Volume:
- 6
- Issue:
- 1
- ISSN:
- 2662-4435
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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