In the context of global warming, hydro-meteorological extremes, such as droughts and heatwaves have become a major threat to global ecology and socio-economy. The impact of climate change on water, heat, and carbon cycles is marginal, when local microclimates fluctuate within a certain range. However, when the amplitude of climate change exceeds a critical threshold, a complex feedback mechanism will be formed between the land surface and atmosphere – leading to imbalanced water and energy cycles and large-scale disasters. Unfortunately, due to limitations in large-scale observation techniques and theoretical frameworks, determining the climate change tipping point remains a key challenge.
To address this issue, the research team led by Prof. Jianzhi Dong proposed a new framework to estimate the global climate change tipping points. This framework used microwave remote sensing and soil drainage processes to define the tipping points of the water-limited and energy-limited soil moisture - evapotranspiration coupling regimes. When the amplitude of climate change exceeds the tipping point, strong feedback between the soil, vegetation, and atmosphere will occur, which will significantly exacerbate drought intensity and trigger regional water resource crises.
Based on the proposed critical point theory, the research team identified global climate change sensitive areas (Figure 1). These areas are more likely to form strong land-atmosphere interactions, which eventually lead to abrupt and nonlinear changes in regional water, heat, and carbon cycles under future climate change.
Figure 1: Global hotspots of climate change
This study was published on Water Resources Research, with Prof. Dong Jianzhi as the first author and Prof. Dara Entekhabi at MIT as a collaborator. This research was supported by the National Natural Science Foundation of China (52179021).
References:
Dong, Jianzhi, Ruzbeh Akbar, Andrew F. Feldman, Daniel Short Gianotti, and Dara Entekhabi. "Land Surfaces at the Tipping‐Point for Water and Energy Balance Coupling." Water Resources Research 59, no. 2 (2023): e2022WR032472.
Dong, Jianzhi, Ruzbeh Akbar, Daniel J. Short Gianotti, Andrew F. Feldman, Wade T. Crow, and Dara Entekhabi. "Can surface soil moisture information identify evapotranspiration regime transitions?" Geophysical Research Letters 49, no. 7 (2022): e2021GL097697.
