Functional Relationships Reveal Large Differences in Streamflow Response to eCO2‐Vegetation in Global Water Models

Abstract Rising CO2 levels substantially impact vegetation characteristics and potentially the water cycle. Using 14 global water models, we assess how elevated CO2 (eCO2) affects streamflow (Q) via vegetation dynamics in the period 1901 to 2020. Our results reveal considerable variability in model...

Full description

Saved in:
Bibliographic Details
Main Authors: Haoshan Wei, Yongqiang Zhang, Qi Huang, Changming Liu, Thorsten Wagener
Format: Article
Language:English
Published: Wiley 2025-05-01
Series:Geophysical Research Letters
Online Access:https://doi.org/10.1029/2024GL113685
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract Rising CO2 levels substantially impact vegetation characteristics and potentially the water cycle. Using 14 global water models, we assess how elevated CO2 (eCO2) affects streamflow (Q) via vegetation dynamics in the period 1901 to 2020. Our results reveal considerable variability in model simulations, with discrepancies not only in magnitude but also in the directional trends of Q changes. To study these differences, we compared model outputs against observations from 1,116 small, unimpacted catchments. Functional relationships between climate variables, such as precipitation (P), aridity, and temperature (T), and eCO2‐vegetation‐driven streamflow (QCO2) changes show large deviations between models and observations, especially in response to changing leaf area index (LAI). No model successfully captured the complex non‐linear interactions between vegetation and Q visible in the observations, highlighting the challenges in accurately modeling eCO2‐vegetation effects on the water cycle, particularly in quantifying impacts of changes in LAI and stomatal behavior on Q.
ISSN:0094-8276
1944-8007