2024-04-09 カリフォルニア大学校アーバイン校(UCI)
＜関連情報＞
- https://news.uci.edu/2024/04/09/uc-irvine-scientist-helps-link-climate-change-to-madagascars-megadrought/
- https://www.nature.com/articles/s41612-024-00583-8
マダガスカル南部の干ばつと気候変動が関係 Climate change linked to drought in Southern Madagascar
Angela Rigden,Christopher Golden,Duo Chan & Peter Huybers
npj Climate and Atmospheric Science Published:08 February 2024
DOI:https://doi.org/10.1038/s41612-024-00583-8
Abstract
Southern Madagascar experienced a prolonged drought over the last five years, but whether these conditions are a manifestation of global climate change has been unclear. Here, we document trends beginning as early as 1980 towards a later rainy-season onset across three distinct remotely sensed indicators: precipitation, soil moisture, and vegetation greenness. All three indicators closely covary, particularly over the last decade when satellite observational resolution and accuracy is greatest. Furthermore, observed soil moisture trends early in the rainy season agree with the mean from CMIP6 historical and SSP5-8.5 simulations, but are distinct from pre-industrial control simulations, implicating anthropogenic changes in radiative forcing as the source of the trends. Physically, these models simulate a poleward migration of the mid-latitude jet that leads to a delay in the seasonal steering of storm tracks over Southern Madagascar. Soil moisture trends driven by anthropogenic forcing made the recent drought significantly more likely over 2017–2022 (p < 0.01), and such droughts are expected to become increasingly likely over this century. These results indicate that, although Madagascar has not substantially contributed to global greenhouse gas emissions, farmers in Southern Madagascar will need to adapt to drier conditions early in the rainy season as a consequence of global climate change.
