By scrutinizing the varved sediments of Lake JiangCo situated on the central Tibetan Plateau, the research group was able to construct a high-resolution climate record spanning the past 2000 years. Their findings suggest that a period of warmth and humidity between the 7th and 9th centuries AD corresponded with the zenith of the Tibetan Empire, while a subsequent phase of cold and dry conditions appeared to align with the decline of the empire.
During their preliminary field investigations, the team discovered well-preserved varved sediments in Lake JiangCo. They determined the chronology of a one-meter-long gravity core, encompassing the last two millennia, using varve counting and other radiometric dating techniques. To decode the climatic conditions encapsulated in the sediment, the researchers performed high-resolution XRF elements scanning and carbonate carbon/oxygen isotope analysis.
Biomarkers like alkenones were instrumental in reconstructing temperature and precipitation patterns for the past 2000 years. According to the findings, the epoch between the 7th and 9th centuries AD experienced an unusually warm and humid climate. Upon comparing this climatic window with historical records, the researchers identified that it coincided with the existence of the Tibetan Empire, the only unified local regime on the Tibetan Plateau at that time.
There appeared to be a strong correlation between these climate shifts - transitioning from warm and humid to cold and dry - and the foreign policy changes of the Tibetan Empire. To further illustrate the impact of these climate shifts on the empire, the researchers simulated the cultivation area of highland barley during these two distinct periods. The results indicated a staggering difference of approximately 10.88 million hectares.
The Tibetan Plateau is an ecologically sensitive region where human activities are significantly impacted by climatic conditions. The study underscores how climate change, by influencing agriculture and animal husbandry, can shape the fate of civilizations. The researchers suggest that a warm and humid climate encouraged agricultural and pastoral development, whereas cold and arid conditions hampered these activities, thus playing a pivotal role in the rise and fall of the Tibetan Empire.
This study serves as a poignant reminder of how susceptible societies are to climatic shifts, a lesson that remains relevant in today's context of global warming. As the Tibetan Plateau experiences increased warming and humidification, insights gleaned from studying past human-environment interactions can inform contemporary strategies to mitigate and adapt to climate change.
Research Report:Climate change fostered rise and fall of the Tibetan Empire during 600-800 AD
Related Links
Institute of Tibetan Plateau Research
Climate Science News - Modeling, Mitigation Adaptation
Subscribe Free To Our Daily Newsletters |
Subscribe Free To Our Daily Newsletters |