Last millennium climate variability in the Romanian Carpathians: a synthesis

Abstract

The Carpathian Mountains span Central and Eastern Europe and provide vital ecosystem functions and services. For this reason, the conservation status of the Carpathians is critical due to environmental pressures such as deforestation and the impacts of climate change, which has significantly affected the region's ecosystem dynamics and communities through increased frequency of floods and landslides as well as changes in species distribution. Paleoclimatic proxy archives are essential to identifying climate trends. This paper aims to synthesize the climatic changes observed in the Romanian Carpathians in the last millennium, having paleoclimatic records as a base. During the Medieval Climate Anomaly (MCA) period in the Romanian Carpathians, wetter conditions prevailed mainly during the first part of this period, followed by a drying trend until the end of the MCA, while slightly warmer conditions were observed throughout the entire period. The timings were somewhat different between the northern and southern regions of the Romanian Carpathians. Another important climatic period, the Little Ice Age (LIA), was characterized by highly variable climatic conditions linked to forcings such as volcanic eruptions and solar activity. LIA was generally dry with intermittent episodes of heavy rains. Winter temperatures dropped between AD 1500 and 1750, while currently available proxy records suggest that summer temperatures were slightly above average. The LIA reached its coldest point in the early 19th century. Since then, Romania has been experiencing warmer conditions, during the so-called Current Warm Period (CWP), with temperatures increasing significantly after 1970, leading to negative impacts on agriculture and hydrology. While positive precipitation anomalies were recorded in the 19th and early 20th centuries, a decline in precipitation has been widely observed since 1970, with an increased occurrence of extreme climatic events. The current warm period in Romania is part of a larger trend of global warming attributed to human activities, such as fossil fuel combustion, leading to environmental and socioeconomic impacts. These paleoclimatic observations provide context for current climatic trends and emphasize the need for joint efforts by governments, NGOs, and local communities to develop adaptation and mitigation strategies in order to reduce the potential negative impacts of climate change on Romania's environment and population.