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The middle reaches of the Lancang‐Mekong River Basin (M‐LMRB) experienced a record‐breaking drought event in 2019, resulting in significant economic losses of approximately 650 million dollars and affecting a population of 17 million. However, the anomalous circulation and transportation processes of water vapor, which may have played a crucial role in inducing the extreme drought, have not been fully studied. In this study, we analyze the water vapor circulation during the 2019 drought event using the land‐atmosphere water balance and a backward trajectory model for moisture tracking. Our results indicate that the precipitation in the M‐LMRB from May to October 2019 was only 71.9% of the long‐term climatological mean (1959–2021). The low precipitation during this drought event can be attributed to less‐than‐normal external water vapor supply. Specifically, the backward trajectory model reveals a decrease in the amount of water vapor transported from the Indian Ocean, the Bay of Bengal, and the Pacific Ocean, which are the main moisture sources for precipitation in the region. Comparing the atmospheric circulation patterns in 2019 with the climatology, we identify anomalous anticyclone conditions in the Bay of Bengal, anomalous westerlies in the Northeast Indian Ocean, and an anomalous cyclone in the Western Pacific Ocean, collectively facilitating a stronger export of water vapor from the region. Therefore, the dynamic processes played a more significant role than thermodynamic processes in contributing to the 2019 extreme drought event. Plain Language Summary: In 2019, a record‐breaking drought hit the M‐LMRB, leading to significant economic losses and affecting a large population. This study explores the water vapor circulation during this drought using land‐atmosphere water balance and a backward trajectory model. Findings show that precipitation from May to October 2019 was only seventy percent of the average from 1959 to 2021. The drought's severity was mainly due to a lack of water vapor from key sources: the Indian Ocean, the Bay of Bengal, and the Pacific Ocean. Anomalous weather patterns—an anticyclone in the Bay of Bengal, unusual westerlies in the Northeast Indian Ocean, and a cyclone in the Western Pacific—led to a significant reduction in water vapor reaching the region. This indicates that dynamic atmospheric processes played a larger role in causing the extreme drought than thermodynamic ones. These insights help improve understanding and prediction of droughts in Southeast Asia, particularly under changing climate conditions. Key Points: Reduced external water vapor transport primarily leads to negative precipitation anomaliesThere has been a reduction in water vapor originating from the Indian Ocean, Bay of Bengal, and Pacific OceanThe reduction in water vapor transport is primarily influenced by dynamic factors rather than thermodynamic ones [ABSTRACT FROM AUTHOR]

Global warming has intensified the intensity of compound drought‐hot extremes (CDHEs), posing more severe impacts on human societies and ecosystems than individual extremes. The vulnerability of global terrestrial ecosystems under CDHEs, along with its key influencing factors, remains poorly understood. Based on multiple remote sensing data, we construct a Vine Copula model to appraise vegetation vulnerability under CDHEs, and attribute it to climatic and biotic factors for five different vegetation types. High vulnerability is detected in central and southern regions of North America, eastern and southern regions of South America, Southern Africa, northern and western Europe, and northern and eastern Australia. The drier the climate, the higher will be the vulnerability. Furthermore, biodiversity and biomass are key biotic factors influencing the vulnerability of various vegetation types, such that ecosystems with richer biodiversity and higher biomass have lower vulnerability to CDHEs. The findings deepen understanding of terrestrial ecosystem response to CDHEs. Plain Language Summary: Drought and hot‐related extremes often coincide or follow one another, known as compound drought‐hot extremes (CDHEs), adversely affecting various vegetation processes. Thus, investigating the response relationship between vegetation dynamics and CDHEs is critical for maintaining the sustainable development of ecosystems under the background of climate warming. High ecosystem vulnerability is detected in central and southern regions of North America, eastern and southern regions of South America, Southern Africa, northern and western Europe, and northern and eastern Australia. Climatic factors (precipitation, arid index, temperature, and radiation) dominate the vulnerability of all vegetation types. The drier the climate, the higher will be the vulnerability of vegetation to CDHEs. Furthermore, biodiversity and biomass are key biotic factors influencing the vulnerability. The results provide us with essential insights for managing and adapting terrestrial ecosystems against climate change and are of interest to a wide range of audiences, including but not limited to ecologists, hydrologists, and climatologists. Key Points: A framework is developed to estimate the vegetation vulnerability in response to compound drought‐hot extremes and attribute it to various factorsVegetation vulnerability is higher for grasses and shrubs than for evergreen and deciduous forestsVegetation vulnerability is both affected by climate and biotic factors, but climate factors are more dominant [ABSTRACT FROM AUTHOR]

Climate change impacts due to unprecedented rising concentrations of greenhouse gas (GHG) are intensifying and widespread, making extreme climate events more widespread, frequent, and severe. To mitigate the worst consequences of climate warming, herein it is investigated how the global community can collectively achieve a large‐scale, sustained reduction in GHG emissions, and how to effectively move away from a predominantly fossil fuel‐based economy to one dominated by renewable energy? This transition is necessary to achieve the sustainable development goals (SDGs) of United Nations (UN) to ensure resilient and healthy environment for present and future generations, especially the SDG 7 of UN, "Affordable and Clean Energy", set up to achieve global development of modern renewable energy systems. Investment policies and patterns of developed and developing countries in transitioning to energy productions primarily from renewable sources and obstacles such as scale‐up challenges, innovations in new energy systems, policies, financing mechanisms, and implementation strategies are examined. Furthermore, a comprehensive overview of the present global status of hydropower, wind, and solar, the three most significant renewable electricity technologies, as well as their basic operating principles, costs, and potential is conducted. Hydroelectric, wind, and solar power had grown from 3429, 346, and 34 TWh yr−1 in 2010 to 4274, 1598, and 846 TWh yr−1 in 2020, a growth of about 1.25, 4.60, and 24.9 times in a decade, respectively. Strategies to achieve energy systems that are of or near net zero GHG emissions by 2050s through the deployment of renewable energy systems are also investigated. [ABSTRACT FROM AUTHOR]