Premium
Interaction of impacts of doubling CO 2 and changing regional land‐cover on evaporation, precipitation, and runoff at global and regional scales
Author(s) -
Li Zhao,
Mölders Nicole
Publication year - 2008
Publication title -
international journal of climatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.58
H-Index - 166
eISSN - 1097-0088
pISSN - 0899-8418
DOI - 10.1002/joc.1666
Subject(s) - evapotranspiration , environmental science , precipitation , land cover , water cycle , surface runoff , climatology , atmospheric sciences , hydrology (agriculture) , land use , geography , geology , meteorology , ecology , geotechnical engineering , biology
The Community Climate System Model version 2.0.1 is running for 40 years under 355 ppm CO 2 conditions, without and with natural and anthropogenic land‐cover changes that are assumed in the inner core of four hydrothermally different, but similar‐sized (≈3.27 x 10 6 km 2 ) regions (Yukon, Ob, St. Lawrence, Colorado, and lands adjacent to them). A further set of simulations assumes 710 ppm CO 2 conditions without and with these land‐cover changes. Impacts of (1) doubled CO 2 , (2) changed land‐cover, and (3) the interaction between doubled CO 2 and changed land‐cover on the four regional water cycles are elucidated using analysis of variance plus multiple testing. For the Yukon, Ob, and St. Lawrence regions, doubling CO 2 significantly increases precipitation, evapotranspiration, and residence time nearly year‐round; the opposite is true for precipitation and evapotranspiration in Colorado. In general, doubling CO 2 slows down water cycles regardless of land‐cover changes. Since land‐cover changes occur locally, they more strongly affect regional than global water cycling. Sometimes land‐cover changes alone reduce regional‐scale precipitation and evapotranspiration. Water‐cycle changes of comparable absolute magnitude can occur in response to either changed land‐cover or doubled CO 2 . Significant interactions between the two treatments indicate that local land‐cover changes, even if they have little impact under reference climate conditions, may have substantial regional impact in a warmer climate. Increased residence time after doubling CO 2 indicates a generally increased influence of upwind regions on downwind regions. If land‐cover changes occur concurrently with CO 2 changes, they will have farther‐reaching impact than under reference CO 2 conditions. Thus, due to atmospheric transport the interaction between impact of land‐cover changes and CO 2 doubling on water‐cycle‐relevant quantities may occur even in regions with unchanged land‐cover. A sensitivity study for tripled CO 2 showed similar results, but more pronounced slowed‐down regional water cycles and interaction of the two treatments. Copyright © 2008 Royal Meteorological Society