Assessing Drought Shifts in Eurasia: The Role of Climate Change

A recent study utilizing tree ring data reveals that rising global temperatures are significantly contributing to altered drought conditions across Eurasia. The research indicates that modern drought severity cannot be attributed to natural variability alone, with eastern Europe and parts of Russia becoming drier while northern Europe and eastern Asia are experiencing wetter conditions.

Assessing the global shifts in drought conditions involves distinguishing between natural hydroclimatic variability and the impacts of climate change. Scientists employ advanced computer models to simulate past climates and gauge current drought situations. While these models provide valuable insights, they sometimes introduce biases affecting the reliability of drought estimates in certain areas.

Tree rings serve as historical indicators of climate, reflecting variations based on climatic conditions—wider during moist years and narrower in dry periods. Researchers, led by Marvel et al., utilized tree ring data to analyze drought patterns across Europe and Asia, employing the Great Eurasian Drought Atlas (GEDA), which spans records from numerous trees from 1000 to 2020 CE.

The study segmented GEDA data into regions as outlined in the Intergovernmental Panel on Climate Change’s Sixth Assessment Report. By examining tree ring data from 1000 to 1849, researchers established preindustrial averages of drought severity using the Palmer Drought Severity Index (PDSI) and compared these with modern values from 1850 to 2020.

The findings indicate that, in numerous regions, contemporary PDSI variations are more accurately attributed to escalating global temperatures rather than solely to natural variability. The research pointed out that areas such as eastern Europe, the Mediterranean, and Arctic Russia are experiencing increased dryness, while northern Europe, east central Asia, and Tibet are witnessing wetter conditions.

While acknowledging potential influences on tree ring growth, the researchers deemed their impact on results minimal, as the GEDA encompasses data mainly from tree species and locations where climate conditions predominantly dictate growth patterns.

The study conducted by Marvel et al. elucidates the complex relationship between climate change and drought conditions across Eurasia. The results suggest that modern climatic phenomena cannot be attributed solely to natural variability, emphasizing the significant role of rising temperatures. Consequently, distinct regional trends of increasing aridity and wetness underscore the urgent need to address climate change implications in environmental planning and policy.

Original Source: eos.org