A model based investigation of the relative importance of CO2-fertilization, climate warming, nitrogen deposition and land use change on the global terrestrial carbon uptake in the historical period

Devaraju, N and Bala, G and Caldeira, Ken and Nemani, R (2016) A model based investigation of the relative importance of CO2-fertilization, climate warming, nitrogen deposition and land use change on the global terrestrial carbon uptake in the historical period. In: CLIMATE DYNAMICS, 47 (1-2). pp. 173-190.

PDF Cli_Dyn_47-1_173_2016.pdf - Published Version Restricted to Registered users only Download (8MB) | Request a copy

Abstract

In this paper, using the fully coupled NCAR Community Earth System Model (CESM1.0.4), we investigate the relative importance of CO2-fertilization, climate warming, anthropogenic nitrogen deposition, and land use and land cover change (LULCC) for terrestrial carbon uptake during the historical period (1850-2005). In our simulations, between the beginning and end of this period, we find an increase in global net primary productivity (NPP) on land of about 4 PgCyr(-1) (8.2 %) with a contribution of 2.3 PgCyr(-1) from CO2-fertilization and 2.0 PgCyr(-1) from nitrogen deposition. Climate warming also causes NPP to increase by 0.35 PgCyr(-1) but LULCC causes a decline of 0.7 PgCyr(-1). These results indicate that the recent increase in vegetation productivity is most likely driven by CO2 fertilization and nitrogen deposition. Further, we find that this configuration of CESM projects that the global terrestrial ecosystem has been a net source of carbon during 1850-2005 (release of 45.1 +/- 2.4 PgC), largely driven by historical LULCC related CO2 fluxes to the atmosphere. During the recent three decades (early 1970s to early 2000s), however, our model simulations project that the terrestrial ecosystem acts as a sink, taking up about 10 PgC mainly due to CO2 fertilization and nitrogen deposition. Our results are in good qualitative agreement with recent studies that indicate an increase in vegetation production and water use efficiency in the satellite era and that the terrestrial ecosystem has been a net sink for carbon in recent decades.

Item Type:	Journal Article
Publication:	CLIMATE DYNAMICS
Additional Information:	Copy right for this article belongs to the SPRINGER, 233 SPRING ST, NEW YORK, NY 10013 USA
Department/Centre:	Division of Mechanical Sciences > Divecha Centre for Climate Change Division of Mechanical Sciences > Centre for Atmospheric & Oceanic Sciences
Date Deposited:	22 Oct 2016 09:28
Last Modified:	28 Feb 2019 05:30
URI:	http://eprints.iisc.ac.in/id/eprint/55033

Actions (login required)

View Item