Impact of Climate Change on Drought Conditions in Eurasia

Marvel et al. researched drought conditions in Europe and Asia using tree ring data from the Great Eurasian Drought Atlas. Their findings indicate that modern drought patterns from 1850 to 2020 cannot be attributed solely to natural variability; instead, they correlate strongly with rising global temperatures, highlighting a shift in drought conditions across various regions.

Determining the impact of shifting drought conditions globally due to natural variability versus climate change poses a significant challenge. Scientists utilize sophisticated computer models to simulate historical climate variations and to identify unusual drought occurrences. However, these models may possess biases that can influence the reliability of drought estimates in specific regions, necessitating additional data sources for a comprehensive analysis.

In their research, Marvel et al. utilized tree ring measurements to investigate drought across Europe and Asia, employing the newly established Great Eurasian Drought Atlas (GEDA). This atlas encompasses records from thousands of trees that witnessed growth from 1000 to 2020 CE. By segmenting the GEDA data according to the land regions described in the Intergovernmental Panel on Climate Change’s Sixth Assessment Report, the researchers sought to enhance their drought analysis.

The team analyzed tree ring data from 1000 to 1849 to estimate preindustrial variations in the Palmer Drought Severity Index (PDSI)—a widely used metric of drought risk. They further compared historical PDSI values to modern data spanning 1850 to 2020 to evaluate whether natural variability could account for current drought conditions. Their findings revealed that rising global temperatures predominantly explain contemporary PDSI changes in numerous regions.

Results indicated that eastern Europe, the Mediterranean, and Arctic Russia are experiencing increasing dryness attributed to climate warming, while northern Europe, east central Asia, and Tibet are witnessing higher moisture levels. Although tree rings can be influenced by factors beyond climate change, the researchers maintained that the influence of those factors on their results is minimal, as GEDA focuses on locations and tree species largely governed by climatic conditions.

In conclusion, the research conducted by Marvel et al. underscores the significant role of climate change in shaping drought conditions across Europe and Asia. Their use of tree ring data, along with the Great Eurasian Drought Atlas, reveals that contemporary drought patterns cannot be solely attributed to natural variability. Instead, the data indicate that modern droughts are strongly correlated with rising global temperatures, further emphasizing the urgency of addressing climate change.

Original Source: eos.org