Recent research utilizing tree ring data reveals that rising global temperatures have a significant impact on drought conditions across Europe and Asia. The study compares historical data with recent observations, finding that modern drought changes cannot solely be attributed to natural variability. The findings indicate varied effects across different regions, with some becoming drier while others receive more precipitation.
Determining the extent of drought conditions attributable to natural variability versus climate change is complex. Scientists utilize advanced computer models to simulate historical climate variations and detect unprecedented droughts, yet these models can present biases that may compromise the reliability of drought assessments in certain areas.
Tree rings, which reflect historical climate conditions by showing wider growth in warmer years and narrower in drier years, provide a complementary approach to model-based climate analysis. Researchers, led by Marvel et al., have utilized the newly developed Great Eurasian Drought Atlas (GEDA), comprising measurements from thousands of trees grown between 1000 and 2020 CE, to investigate drought patterns across Europe and Asia.
By analyzing tree ring data from 1000 to 1849, the research team estimated preindustrial variations in drought risk using the Palmer Drought Severity Index (PDSI). They then compared these historical variations to modern PDSI values from 1850 to 2020 to ascertain if preindustrial data could account for current drought conditions.
The findings reveal that rising global temperatures explain many contemporary PDSI changes more effectively than natural variability alone. Specifically, southeastern Europe, the Mediterranean, and Arctic Russia are experiencing increasing dryness, while northern Europe, east-central Asia, and Tibet are witnessing greater precipitation.
Although tree ring data can be influenced by non-climatic factors, the researchers assert these factors are unlikely to significantly bias their outcomes due to the controlled environment of the GEDA database, which selectively samples locations and tree species predominantly influenced by climate.
This study emphasizes the crucial role of climate change in altering drought conditions across Eurasia. By bridging tree ring data with modern climate models, researchers have established that rising temperatures are significantly influencing drought severity, challenging the notion that such changes arise solely from natural variability. As climate impacts continue to evolve, understanding these dynamics becomes vital for effective environmental management strategies.
Original Source: eos.org
