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Unprecedented drought conditions projected to be more frequent and consecutive in certain regions

Phys.org/news (JUNE 28, 2022)

Titre : Unprecedented drought conditions projected to be more frequent and consecutive in certain regions

A new study presents the future periods for which aberrant drought conditions will become more frequent, thereby creating a new normal. The projected warming impacts show significant regional disparities in their intensity and the pace of their growth over time. In approximately 30–50 years, unprecedented drought conditions are projected to be more frequent and consecutive in certain regions even with a low greenhouse gas concentration scenario. The results imply unavoidable unprecedented states in these regions.

Phys.org/news (JUNE 28, 2022)

Présentation
For a successful climate change strategy, it is crucial to understand how the impacts of global warming may evolve over time. A new study led by the National Institute for Environmental Studies (NIES) presents the future periods for which aberrant drought conditions will become more frequent, thereby creating a new normal.

Global warming is expected to increase the intensity and frequency of future drought in several global regions, adversely affecting the water resource, agriculture, and energy sectors. Given that the current water management practices and existing infrastructures in these sectors are based on historical statistics or experiences, under a changing climate, these practices and infrastructures may eventually become insufficient. Therefore, it is critical to better understand when severe drought conditions expressed as "unprecedented" will become frequent.

The paper published in Nature Communications estimates the periods when drought conditions will shift to an unprecedented state in a warmer world. The research group evaluated changes in drought day frequency for 59 global subcontinental regions until the end of the 21st century. They estimated the time of first emergence (TFE) of consecutive unprecedented drought, which is the first onset of exceedance beyond the maximum bound of the historical climate variability during the reference period (1865–2005) that occurs consecutively for a certain number of years. For instance, TFE5 indicates that the regional drought frequency remains larger than the maximum value during the reference 141-year period for more than five years. The scientists analyzed their river discharge simulation dataset, which was derived from combinations of five global hydrological models and four climate model projections. The study considered low and high greenhouse gas concentration scenarios to evaluate the consequences of society’s decisions on the climate mitigation pathway.

Source  : National Institute for Environmental Studies

Annonce (Phys.org/news)

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