• Energy Research

AbstractObservation‐based and modeling studies have identified the Eastern Mediterranean and Middle East (EMME) region as a prominent climate change hotspot. While several initiatives have addressed the impacts of climate change in parts of the EMME, here we present an updated assessment, covering a wide range of timescales, phenomena and future pathways. Our assessment is based on a revised analysis of recent observations and projections and an extensive overview of the recent scientific literature on the causes and effects of regional climate change. Greenhouse gas emissions in the EMME are growing rapidly, surpassing those of the European Union, hence contributing significantly to climate change. Over the past half‐century and especially during recent decades, the EMME has warmed significantly faster than other inhabited regions. At the same time, changes in the hydrological cycle have become evident. The observed recent temperature increase of about 0.45°C per decade is projected to continue, although strong global greenhouse gas emission reductions could moderate this trend. In addition to projected changes in mean climate conditions, we call attention to extreme weather events with potentially disruptive societal impacts. These include the strongly increasing severity and duration of heatwaves, droughts and dust storms, as well as torrential rain events that can trigger flash floods. Our review is complemented by a discussion of atmospheric pollution and land‐use change in the region, including urbanization, desertification and forest fires. Finally, we identify sectors that may be critically affected and formulate adaptation and research recommendations toward greater resilience of the EMME region to climate change.

Abstract. The influence of air pollutants, especially aerosols, on regional and global climate has been widely investigated, but only a very limited number of studies report their impacts on everyday weather. In this work, we present for the first time direct (observational) evidence of a clear effect of how a mixed atmospheric pollution changes the weather with a substantial modification in the air temperature and rainfall. By using comprehensive measurements in Nanjing, China, we found that mixed agricultural burning plumes with fossil fuel combustion pollution resulted in a decrease in the solar radiation intensity by more than 70%, a decrease in the sensible heat by more than 85%, a temperature drop by almost 10 K, and a change in rainfall during both daytime and nighttime. Our results show clear air pollution–weather interactions, and quantify how air pollution affects weather via air pollution–boundary layer dynamics and aerosol–radiation–cloud feedbacks. This study highlights cross-disciplinary needs to investigate the environmental, weather and climate impacts of the mixed biomass burning and fossil fuel combustion sources in East China.

The nucleation of atmospheric vapours is an important source of new aerosol particles that can subsequently grow to form cloud condensation nuclei in the atmosphere1. Most field studies of atmospheric aerosols over continents are influenced by atmospheric vapours of anthropogenic origin (for example, ref. 2) and, in consequence, aerosol processes in pristine, terrestrial environments remain poorly understood. The Amazon rainforest is one of the few continental regions where aerosol particles and their precursors can be studied under near-natural conditions3,4,5, but the origin of small aerosol particles that grow into cloud condensation nuclei in the Amazon boundary layer remains unclear6,7,8. Here we present aircraft- and ground-based measurements under clean conditions during the wet season in the central Amazon basin. We find that high concentrations of small aerosol particles (with diameters of less than 50 nanometres) in the lower free troposphere are transported from the free troposphere into the boundary layer during precipitation events by strong convective downdrafts and weaker downward motions in the trailing stratiform region. This rapid vertical transport can help to maintain the population of particles in the pristine Amazon boundary layer, and may therefore influence cloud properties and climate under natural conditions.

The international Pan-Eurasian Experiment (PEEX) program addresses the full spectrum of problems related to climate change in Eurasian Northern latitudes. Todas las actividades de PEEX se centran en el gran volumen de datos observacionales de alta calidad proporcionados por las estaciones terrestres y marinas, la detección remota y las herramientas satelitales. So far, no coordinated station network has ever existented in Eurasia, moreover, the current scope of relevant research remains largely unknown as no prior assessment has been done to date. This paper makes the first attempt to overview the existing ground station pool in the Arctic-Boreal region with the focus on Russia. The geographical, climatic and ecosystem representativeness of the current stations is discussed, the gaps are identified and tentative station network developments are proposed. The international Pan-Eurasian Experiment (PEEX) program addresses the full spectrum of problems related to climate change in Eurasian Northern latitudes. Toutes les activités PEEX sont liées au volume de données d'observation de haute qualité fournies par les stations terrestres et marines, la détection à distance et les outils satellites. So far, no coordinated station network has ever existd in Eurasia, moreover, the current scope of relevant research remains largely unknown as no prior assessment has been done to date. This paper makes the first attempt to overview the existing ground station pool in the Arctic-Boreal region with the focus on Russia. The geographical, climatic and ecosystem representativess of the current stations is discussed, the gaps are identified and tentative station network developments are proposed. The international Pan-Eurasian Experiment (PEEX) program addresses the full spectrum of problems related to climate change in Eurasian Northern latitudes. All PEEX activities rely on the bulk of high-quality observational data provided by the ground and marine stations, remote sensing and satellite tools. So far, no coordinated station network has ever existed in Eurasia, moreover, the current scope of relevant research remains largely unknown as no prior assessment has been done to date. This paper makes the first attempt to overview the existing ground station pool in the Arctic-Boreal region with the focus on Russia. The geographical, climatic and ecosystem representativeness of the current stations is discussed, the gaps are identified and tentative station network developments are proposed. The international Pan-Eurasian Experiment (PEEX) program addresses the full spectrum of problems related to climate change in Eurasian Northern latitudes. All PEEX activities rely on the bulk of high-quality observational data provided by the ground and marine stations, remote sensing and satellite tools. So far, no coordinated station network has ever existed in Eurasia, moreover, the current scope of relevant research remains largely unknown as no prior assessment has been done to date. This paper makes the first attempt to overview the existing ground station pool in the Arctic-Boreal region with the focus on Russia. The geographical, climatic and ecosystem representativeness of the current stations is discussed, the gaps are identified and tentative station network developments are proposed. يعالج البرنامج الدولي للتجربة الأوراسية (PEEX) مجموعة كاملة من المشاكل المتعلقة بتغير المناخ في خطوط العرض الشمالية الأوراسية. تعتمد جميع أنشطة PEEX على الجزء الأكبر من بيانات الرصد عالية الجودة التي توفرها المحطات الأرضية والبحرية والاستشعار عن بعد وأدوات الأقمار الصناعية. حتى الآن، لم تكن هناك شبكة محطات منسقة في أوراسيا، علاوة على ذلك، لا يزال النطاق الحالي للبحوث ذات الصلة غير معروف إلى حد كبير حيث لم يتم إجراء تقييم مسبق حتى الآن. تقوم هذه الورقة بالمحاولة الأولى لإلقاء نظرة عامة على مجموعة المحطات الأرضية الحالية في المنطقة القطبية الشمالية مع التركيز على روسيا. تتم مناقشة التمثيل الجغرافي والمناخي والنظم الإيكولوجية للمحطات الحالية، ويتم تحديد الفجوات واقتراح تطويرات مؤقتة لشبكة المحطات.