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Synergy of rising nitrogen depositions and atmospheric CO 2 on land carbon uptake moderately offsets global warming
Author(s) -
Churkina Galina,
Brovkin Victor,
von Bloh Werner,
Trusilova Kristina,
Jung Martin,
Dentener Frank
Publication year - 2009
Publication title -
global biogeochemical cycles
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.512
H-Index - 187
eISSN - 1944-9224
pISSN - 0886-6236
DOI - 10.1029/2008gb003291
Subject(s) - biogeochemistry , environmental science , nitrogen , deposition (geology) , carbon fibers , ecosystem , climate change , carbon sequestration , environmental chemistry , greenhouse gas , atmospheric carbon cycle , carbon cycle , reforestation , atmospheric sciences , chemistry , ecology , agroforestry , geology , biology , paleontology , materials science , organic chemistry , sediment , composite number , composite material
Increased carbon uptake of land in response to elevated atmospheric CO 2 concentration and nitrogen deposition could slow down the rate of CO 2 increase and facilitate climate change mitigation. Using a coupled model of climate, ocean, and land biogeochemistry, we show that atmospheric nitrogen deposition and atmospheric CO 2 have a strong synergistic effect on the carbon uptake of land. Our best estimate of the global land carbon uptake in the 1990s is 1.34 PgC/yr. The synergistic effect could explain 47% of this carbon uptake, which is higher than either the effect of increasing nitrogen deposition (29%) or CO 2 fertilization (24%). By 2030, rising carbon uptake on land has a potential to reduce atmospheric CO 2 concentration by about 41 ppm out of which 16 ppm reduction would come from the synergetic response of land to the CO 2 and nitrogen fertilization effects. The strength of the synergy depends largely on the cooccurrence of high nitrogen deposition regions with nonagricultural ecosystems. Our study suggests that reforestation and sensible ecosystem management in industrialized regions may have larger potential for climate change mitigation than anticipated.