Experimental Evidence of Plant Thermoregulation and Its Implications for Climate Stability

Authors

  • Peter Paul Bunyard

    Independent Scientist, Bodmin PL30 5NW, UK

DOI:

https://doi.org/10.30564/jasr.v8i4.12145
Received: 20 July 2025 | Revised:12 September 2025 | Accepted:20 September 2025 | Published Online: 27 September 2025

Abstract

Ongoing experiments reveal that plants of different species actively regulate their surface temperature by means of varying their rate of evapotranspiration. The overall cooling under hot weather conditions and bright sunlight may amount to as much as 20 ℃. That degree of cooling is vital in order to counteract the relatively low albedo of the leaves and to leave the plant surface cooler than the ambient temperature. In colder, cloudy conditions, plants reduce their evapotranspiration, with resulting surface temperatures that may exceed ambient temperatures. The evolution of angiosperm forests, on account of their vascularised leaves and relatively high rate of transpiration, may have been a major factor in the cooling of the planet from 100 million years ago, when average global surface temperatures were 6 ℃ higher than today. In addition, a high rate of evapotranspiration will have triggered the inflow of humid air from the ocean, thereby enabling the flourishing of the forests across continents. Physical experiments carried out by the author indicate that water vapour condensation results in partial pressure changes, with resulting airflow, consequently, as physics dictates, cloud condensation over forests will give rise inevitably to ocean-to-continent airflow. Given the role of the forest-derived biotic pump in generating flying rivers over the Amazon Basin, deforestation can result in hydrological collapse. The regeneration and recovery of forests can help cool the Earth’s surface by at least 1 ℃ globally.

Keywords:

Thermoregulation; Biotic Pump; Hydrological Cycle; Global-Warming; Angiosperm Evapotranspiration; Global-Cooling

References

[1] Bunyard, P.P., Collin, E., de Laet, R., et al., 2024. Restoring the Earth’s Damaged Temperature Regulation Is the Fastest Way Out of the Climate Crisis. Cooling the Planet With Plants. International Journal of Biosensors and Bioelectronics. 9(1), 7–15.

[2] Bunyard, P.P., Shahid, A.B., de Laet, R., et al., 2025. In Defence of the Biotic Pump. Journal of Atmospheric Science Research. 8(1), 41–64. DOI: https://doi.org/10.30564/jasr.v8i1.9887

[3] Bunyard, P.P., Hodnett, M., Pena, C., et al., 2019. Further Experimental Evidence That Condensation Is a Major Cause of Airflow. Revista DYNA. 86(209), 56–63.

[4] Bunyard, P.P., de Laet, R., 2024. Restore Ecosystems to Cool the Climate. In: Lackner, M., Sajjadi, B., Chen, W.Y. (Eds.). Handbook of Climate Change Mitigation and Adaptation. Springer: New York, USA. pp. 1–28. DOI: https://doi.org/10.1007/978-1-4614-6431-0_206-1

[5] Daniels, F., Alberty, R.A., 1966. Physical Chemistry, 3rd ed. John Wiley and Sons: New York, USA.

[6] McIlveen, R., 2010. Fundamentals of Weather and Climate, 2nd ed. Oxford University Press: Oxford, UK.

[7] Makarieva, A., Gorshkov, V., 2007. Biotic Pump of Atmospheric Moisture as Driver of the Hydrological Cycle on Land. Hydrology and Earth System Sciences. 11(2), 1013–1033. DOI: https://doi.org/10.5194/hess-11-1013-2007

[8] Salati, E., 1987. The Forest and the Hydrological Cycle. In: Dickinson, R.E. (Ed.). The Geophysiology of Amazonia: Vegetation and Climate Interactions. Wiley: New York, NY, USA. pp. 273–296.

[9] Makarieva, A.M., Gorshkov, V.G., Sheil, D., et al., 2013. Where Do Winds Come From? A New Theory on How Water Vapor Condensation Influences Atmospheric Pressure and Dynamics. Atmospheric Chemistry and Physics. 13(2), 1039–1056. DOI: https://doi.org/10.5194/acp-13-1039-2013

[10] Makarieva, A.M., Gorshkov, V.G., Sheil, D., et al., 2014. Why Does Air Passage Over Forest Yield More Rain? Examining the Coupling Between Rainfall, Pressure and Atmospheric Moisture Content. Journal of Hydrometeorology. 15(1), 411–426. DOI: https://doi.org/10.1175/JHM-D-12-0190.1

[11] Spracklen, D.V., Arnold, S.R., Taylor, C.M., 2012. Observations of Increased Tropical Rainfall Preceded by Air Passage Over Forests. Nature. 489, 282–285. DOI: https://doi.org/10.1038/nature11390

[12] Eiseltová, M., Pokorný, J., Hesslerová, P., et al., 2012. Evapotranspiration – A Driving Force in Landscape Sustainability. In: Irmak, A. (Ed.). Evapotranspiration – Remote Sensing and Modeling. InTech: London, UK. DOI: https://doi.org/10.5772/19441

[13] Middleby, K., 2025. Some Tropical Trees Cool Their Leaves to Survive the Heat—but Not All Species Have Ways to Cope. Available from: https://theconversation.com/some-tropical-trees-cool-their-leaves-to-survive-the-heat-but-not-all-species-have-ways-to-cope-264117 (cited 10 July 2025).

[14] Solano, F., Mansi, C., Baliva, M., et al., 2025. Mediterranean Strictly Protected Forests Are Cooler. Agricultural and Forest Meteorology. 375, 110858. Available from: https://www.sciencedirect.com/science/article/pii/S0168192325004770

[15] Felton, A.J., Fisher, J.B., Hufkens, K., et al., 2025. Global Estimates of the Storage and Transit Time of Water Through Vegetation. Nature Water. 3, 59–69. DOI: https://doi.org/10.1038/s44221-024-00365-9

[16] Hodnett, M.G., Oyama, M.D., Tomasella, J., et al., 1996. Comparisons of Long-Term Soil Water Storage Behaviour Under Pasture and Forest in Three Areas of Amazonia. In: Gash, J., Nobre, C.A., Roberts, J.M., et al. (Eds.). Amazonian Deforestation and Climate. Wiley: Chichester, UK. pp. 57–77.

[17] Ban-Weiss, G.A., Bala, G., Cao, L., et al., 2011. Climate Forcing and Response to Idealized Changes in Surface Latent and Sensible Heat. Environmental Research Letters. 6(3), 034032. DOI: https://doi.org/10.1088/1748-9326/6/3/034032

[18] Harde, H., 2013. Radiation and Heat Transfer in the Atmosphere: A Comprehensive Approach on a Molecular Basis. International Journal of Atmospheric Sciences. 2013, 503727. DOI: https://doi.org/10.1155/2013/503727

[19] Anadón, J.D., Sala, O.E., Maestre, F.T., 2014. Climate Change Will Increase Savannas at the Expense of Forests and Treeless Vegetation in Tropical and Subtropical Americas. Journal of Ecology. 102(6), 1363–1373. DOI: https://doi.org/10.1111/1365-2745.12325

[20] Bunyard, P.P., 2014. How the Biotic Pump Links the Hydrological Cycle and the Rainforest to Climate: Is It for Real? How Can We Prove It? Instituto de Estudios y Servicios Ambientales-IDEASA: Bogotá, Colombia. p. 114.

[21] Wood, R., Bretherton, C.S., Hartmann, D.L., 2002. Diurnal Cycle of Liquid Water Path over the Subtropical and Tropical Oceans. Geophysical Research Letters. 29(23), 2092. DOI: https://doi.org/10.1029/2002GL015371

[22] Boyce, C.K., Lee, J.E., Field, T.S., et al., 2010. Angiosperms Helped Put the Rain in the Rainforests: The Impact of Plant Physiological Evolution on Tropical Biodiversity. Annals of the Missouri Botanical Garden. 97(4), 527–540. DOI: https://doi.org/10.3417/2009143

[23] Benton, M.J., Wilf, P., Sauquet, H., 2022. The Angiosperm Terrestrial Revolution and the Origins of Modern Biodiversity. New Phytologist. 233(5), 2017–2035. DOI: https://doi.org/10.1111/nph.17822

[24] Koch, A., Brierly, C., Maslin, M.M., et al., 2019. Earth System Impacts of the European Arrival and Great Dying in the Americas After 1492. Quaternary Science Reviews. 207, 13–36.

[25] Marull, Y., 2012. Amazon’s Flying Water Vapor Rivers Bring Rain to Brazil. Phys.org. Available from: https://phys.org/news/2012-09-amazon-vapor-rivers-brazil.html (cited 13 November 2014).

[26] Wu, Y., Wen, B., Ye, T., et al., 2025. Estimating the Urban Heat-Related Mortality Burden Due to Greenness: A Global Modelling Study. Lancet Planetary Health. 9(7), 101235. DOI: https://doi.org/10.1016/S2542-5196(25)00062-2

[27] Barrett, P., 1999. Antarctic Climate History Over the Last 100 Million Years. Terra Antarctica Reports. 3, 43–72.

[28] Pagani, M., Zachos, J.C., Freeman, K.H., et al., 2005. Marked Decline in Atmospheric Carbon Dioxide Concentrations During the Paleogene. Science. 309(5734), 600–603. DOI: https://doi.org/10.1126/science.1110063

[29] de Laet, R., 2025. Cooling the Planet and Arara Platform Explained. Available from: https://www.youtube.com/watch?v=Iw5rhu6ErvE (cited 10 July 2025).

[30] Bunyard, P.P., 2022. James Lovelock: The Vision of an Exceptional Scientist. Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales. 46(180), 823–831. DOI: http://doi.org/10.18257/raccefyn.1771 (in Spanish)

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How to Cite

Bunyard, P. P. (2025). Experimental Evidence of Plant Thermoregulation and Its Implications for Climate Stability. Journal of Atmospheric Science Research, 8(4), 66–82. https://doi.org/10.30564/jasr.v8i4.12145

Issue

Vol. 8 , Iss. 4 (October 2025)

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ARTICLE

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Copyright © 2025 Peter Paul Bunyard

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This is an open access article under the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) License.

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