Research indicates that shifts in drought conditions across Europe and Asia are more closely linked to climate change than to natural variability. Using tree ring data from the Great Eurasian Drought Atlas, scientists found that while some regions are becoming drier, others are experiencing increased precipitation due to rising global temperatures.
The complexities of understanding global drought conditions arise from determining the influence of natural hydroclimatic variability versus climate change. Researchers utilize advanced computer models to simulate historical climate patterns and pinpoint unprecedented drought events. While these models analyze factors like temperature, precipitation, and land use changes, they may possess biases that could undermine the reliability of drought assessments in certain areas.
Tree rings serve as a valuable tool for assessing historical climate variability, as they tend to indicate wetter years through wider rings and drier years through narrower rings. In a recent study, Marvel et al. utilized the Great Eurasian Drought Atlas (GEDA), which encompasses measurements from thousands of trees growing between 1000 and 2020 CE, to explore drought conditions across Europe and Asia.
The research team categorized the GEDA data in accordance with the regions established in the Intergovernmental Panel on Climate Change’s Sixth Assessment Report. By analyzing tree ring measurements from 1000 to 1849, they estimated preindustrial variations of the Palmer Drought Severity Index (PDSI) for each region and compared these to modern values from 1850 to 2020.
The study’s findings revealed that shifts in modern PDSI are increasingly attributable to rising global temperatures, suggesting that recent drought conditions cannot be solely explained by natural variability. Specifically, regions like eastern Europe, the Mediterranean, and Arctic Russia are experiencing increased aridity with climate change, while northern Europe, east central Asia, and Tibet are witnessing increasing precipitation.
Although tree rings may be influenced by factors beyond climate variability, the researchers argue these are unlikely to have significantly impacted their results. The GEDA database focuses on samples from selected locations and tree species where climate impacts on growth are predominant.
The study emphasizes that changes in drought conditions across Eurasia are primarily driven by anthropogenic climate change rather than natural variability alone. The evidence of regional differences in moisture levels underscores the impactful role of global temperature rises. This research contributes significantly to understanding the nuanced shifts in hydroclimatic conditions attributable to climate change.
Original Source: eos.org
