title: Observational constraints indicate risk of drying in the Amazon basin.
abstract: Climate warming due to human activities will be accompanied by hydrological cycle changes. Economies, societies and ecosystems in South America are vulnerable to such water resource changes. Hence, water resource impact assessments for South America, and corresponding adaptation and mitigation policies, have attracted increased attention. However, substantial uncertainties remain in the current water resource assessments that are based on multiple coupled Atmosphere Ocean General Circulation models. This uncertainty varies from significant wetting to catastrophic drying. By applying a statistical method, we characterized the uncertainty and identified global-scale metrics for measuring the reliability of water resource assessments in South America. Here, we show that, although the ensemble mean assessment suggested wetting across most of South America, the observational constraints indicate a higher probability of drying in the Amazon basin. Thus, over-reliance on the consensus of models can lead to inappropriate decision making.
authors: Atmospheric Environment Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan. shiogama.hideo@nies.go.jp
authors: Hideo
authors: H
authors: Shiogama
authors: Seita
authors: S
authors: Emori
authors: Naota
authors: N
authors: Hanasaki
authors: Manabu
authors: M
authors: Abe
authors: Yuji
authors: Y
authors: Masutomi
authors: Kiyoshi
authors: K
authors: Takahashi
authors: Toru
authors: T
authors: Nozawa
mesh_terms: D057231:Climate Change; D017753:Ecosystem; D008962:Models, Theoretical; D018570:Risk Assessment; D013020:South America; D035501:Uncertainty; D014867:Water
chemical_list: D014867:Water