Recent global decline in rainfall interception loss due to altered rainfall regimes

Evaporative loss of interception (E_i) is the first process occurring during rainfall, yet its role in large-scale surface water balance has been largely underexplored. Here we show that E_i can be inferred from flux tower evapotranspiration measurements using physics-informed hybrid machine learning models built under wet versus dry conditions. Forced by satellite and reanalysis data, this framework provides an observationally constrained estimate of E_i, which is on average 84.1 ± 1.8 mm per year and accounts for 8.6 ± 0.2% of total rainfall globally during 2000-2020. Rainfall frequency regulates long-term average E_i changes, and rainfall intensity, rather than vegetation attributes, determines the fraction of E_i in gross precipitation (E_i/P). Rain events have become less frequent and more intense since 2000, driving a global decline in E_i (and E_i/P) by 4.9% (6.7%). This suggests that ongoing rainfall changes favor a partitioning towards more soil moisture and runoff, benefiting ecosystem functions but simultaneously increasing flood risks.