Matthews, Tom and Byrne, Michael and Horton, Radley and Murphy, Conor and Pielke, Roger and Raymond, Colin and Thorne, Peter and Wilby, Robert L. (2022) Latent heat must be visible in climate communications. WIREs Climate Change, 13 (4). ISSN 1757-7780

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Abstract

Anthropogenic forcing is driving energy accumulation in the Earth system, including increases in the sensible heat content of the atmosphere, as measured by dry-bulb temperature—the metric that is almost universally used for communications about climate change. The atmosphere is also moistening, though, representing an accumulation of latent heat, which is partly concealed by dry-bulb temperature trends. We highlight that, consistent with basic theory, latent heat gains are outpacing sensible heat gains over about half of the Earth's surface. The difference is largest in the tropics, where global “hotspots” of total heat accumulation are located, and where regional disparities in heating rates are very poorly represented by dry-bulb temperatures. Including latent heat in climate-change metrics captures this heat accumulation and therefore improves adaptation-relevant understanding of the extreme humid heat and precipitation hazards that threaten these latitudes so acutely. For example, irrigation can lower peak dry-bulb temperatures, but amplify latent heat content by a larger margin, intensifying dangerous heat stress. Based on a review of the research literature, our Perspective therefore calls for routine use of equivalent temperature, a measure that expresses the combined sensible and latent heat content of the atmosphere in the familiar units of °C or K. We recognize that dry-bulb air temperature must remain a key indicator of the atmospheric state, not least for the many sectors that are sensitive to sensible heat transfer. However, we assert here that more widespread use of equivalent temperature could improve process understanding, public messaging, and adaptation to climate change.

Item Type:	Article
Keywords:	climate change environment; equivalent temperature; extreme heat; heat accumulation; sensible heat;
Academic Unit:	Faculty of Social Sciences > Geography Faculty of Social Sciences > Research Institutes > Irish Climate Analysis and Research Units, ICARUS
Item ID:	16946
Identification Number:	https://doi.org/10.1002/wcc.779
Depositing User:	Peter Thorne
Date Deposited:	20 Feb 2023 11:14
Journal or Publication Title:	WIREs Climate Change
Publisher:	Wiley
Refereed:	Yes
URI:	Publisher
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

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