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Title: Biogeophysical effects of CO2-fertilization on global climate

Biogeophysical effects of CO2-fertilization on global climate CO{sub 2}-fertilization affects plant growth, which modifies surface physical properties, altering the surface albedo, and fluxes of sensible and latent heat. We investigate how such CO{sub 2}-fertilization effects on vegetation and surface properties would affect the climate system. Using a global three-dimensional climate-carbon model that simulates vegetation dynamics, we compare two multi-century simulations: a ''Control'' simulation with no emissions, and a ''Physiol-noGHG'' simulation where physiological changes occur as a result of prescribed CO{sub 2} emissions, but where CO{sub 2}-induced greenhouse warming is not included. In our simulations, CO{sub 2}-fertilization produces warming; we obtain an annual- and global-mean warming of about 0.65 K (and land-only warming of 1.4 K) after 430 years. This century-scale warming is mostly due to a decreased surface albedo associated with the expansion of the Northern Hemisphere boreal forests. On decadal time scales, the CO{sub 2} uptake by afforestation should produce a cooling effect that exceeds this albedo-based warming; but if the forests remain in place, the CO{sub 2}-enhanced-greenhouse effect would diminish as the ocean equilibrates with the atmosphere, whereas the albedo effect would persist. Thus, on century time scales, there is the prospect for net warming from CO{sub 2}-fertilization of the land biosphere. Further study is more » needed to confirm and better quantify our results. « less
Authors: ; ; ; ; ;
Publication Date:
OSTI Identifier:899439
Report Number(s):UCRL-JRNL-221030
TRN: US200708%%294
DOE Contract Number:W-7405-ENG-48
Resource Type:Journal Article
Data Type:
Resource Relation:Journal Name: Tellus B, vol. 58B, n/a, November 1, 2006, pp. 620-627
Research Org:Lawrence Livermore National Laboratory (LLNL), Livermore, CA
Sponsoring Org:USDOE
Country of Publication:United States
Language:English
Subject: 54 ENVIRONMENTAL SCIENCES; ALBEDO; BIOSPHERE; CLIMATES; FORESTS; GREENHOUSE GASES; NORTHERN HEMISPHERE; PHYSICAL PROPERTIES; PLANT GROWTH; PLANTS; SIMULATION; SURFACE PROPERTIES