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Toward a more comprehensive understanding of aridity changes over global drylands

Phys.org/news ( Mar 11, 2021)

Titre : Toward a more comprehensive understanding of aridity changes over global drylands

Phys.org/news ( Mar 11, 2021)

Présentation
Global drylands are experiencing faster-than-average warming and are also among the most vulnerable regions to climate change. Meteorological metrics all point to an emerging trend of increased surface aridity, raising concerns of land desertification and degradation. However, recent satellite observations also show lusher drylands, in apparent contradiction to the image of drylands becoming drier. In a new review article published in Nature Reviews Earth & Environment, an international team comprehensively examined global dryland aridity changes with evidence from the literature and various sources of Earth observations and numerical modeling. A key message of this synthesis is that, by considering the physiological effect of rising atmospheric carbon dioxide (CO2), the apparent paradox between enhanced surface aridity and lusher dryland vegetation can actually be resolved. Led by researchers from Peking University, the team includes scientists with diverse expertise on global dryland research from China, U.K., France, Australia, U.S. and Austria. By employing a broad range of aridity metrics, the team provided a more complete picture of current and future aridity changes over global drylands. They found that atmospheric-based metrics generally show a strong trend of rising dryness ; while soil moisture and runoff also imply increasing dryland aridity, yet at slower paces. By contrast, ecosystem-based metrics show a trend of greening and reduced plant water stress, despite the rising atmospheric dryness. The co-occurrence of atmospheric drying and ecosystem greening over drylands is also confirmed by model simulations of vegetation dynam

Source  : Peking University

Annonce (Phys.org/news)

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