Our new paper, “The potential of urban irrigation for counteracting carbon-climate feedback“, is published in Nature Communications (IF: 16.6).

The paper and its supplement can be downloaded at https://www.nature.com/articles/s41467-024-46826-3.

Authors: Peiyuan Li, Zhi-Hua Wang, and Chenghao Wang

Abstract: Global climate changes, especially the rise of global mean temperature due to the increased carbon dioxide (CO2) concentration, can, in turn, result in higher anthropogenic and biogenic greenhouse gas emissions. This potentially leads to a positive loop of climate–carbon feedback in the Earth’s climate system, which calls for sustainable environmental strategies that can mitigate both heat and carbon emissions, such as urban greening. In this study, we investigate the impact of urban irrigation over green spaces on ambient temperatures and CO2 exchange across major cities in the contiguous United States. Our modeling results indicate that the carbon release from urban ecosystem respiration is reduced by evaporative cooling in humid climate, but promoted in arid/semi-arid regions due to increased soil moisture. The irrigation-induced environmental co-benefit in heat and carbon mitigation is, in general, positively correlated with urban greening fraction and has the potential to help counteract climate–carbon feedback in the built environment.

DOI: https://doi.org/10.1038/s41467-024-46826-3

Fig. 2: Governing mechanisms on carbon exchange of urban greenery. a A diagram showing carbon exchange of plants in the built environment with UHI, higher background CO2 concentration, and management (irrigation). b Irrigation-induced change of urban gross primary productivity (dGPPu), led by decrease of air temperature and increase of soil water content. c Irrigation-induced change of urban ecosystem respiration (dRu), led by decrease of soil temperature and increase of soil water content. d Irrigation-induced change of urban net ecosystem exchange (dNEEu), resulting from the combinations of dGPPu and dRu. e Urban ecosystem respiration as a function of soil temperature and soil water content. The light gray lines in b–d show all possible combinations lead to various types of outcomes. The black solid lines indicate pathway to the strong co-benefit effect. The red dashed lines indicate the pathway to the strong tradeoff effect. Circles in (e) indicate the average Ru before (hollow) and after (solid) irrigation. Arrows indicate the direction of change.