Abstract
Global and regional land carbon storage has been significantly affected by increasing atmospheric CO2 concentration and climate change. Based on fully coupled climate-carbon-cycle simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5), we investigate sensitivities of land carbon storage to rising atmospheric CO2 concentration and climate change over the world and 21 regions during the 130 years. Overall, the simulations suggest that consistently spatial positive effects of the increasing CO2 concentrations on land carbon storage are expressed with a multi-model averaged value of 1.04PgC per ppm. The stronger positive values are mainly located in the broad areas of temperate and tropical forest, especially in Amazon basin and western Africa. However, large heterogeneity distributed for sensitivities of land carbon storage to climate change. Climate change causes decrease in land carbon storage in most tropics and the Southern Hemisphere. In these regions, decrease in soil moisture (MRSO) and enhanced drought somewhat contribute to such a decrease accompanied with rising temperature. Conversely, an increase in land carbon storage has been observed in high latitude and altitude regions (e.g., northern Asia and Tibet). The model simulations also suggest that global negative impacts of climate change on land carbon storage are predominantly attributed to decrease in land carbon storage in tropics. Although current warming can lead to an increase in land storage of high latitudes of Northern Hemisphere due to elevated vegetation growth, a risk of exacerbated future climate change may be induced due to release of carbon from tropics.
Highlights
Variations in the whole terrestrial carbon cycle are accompanied with increasing atmospheric CO2 concentration and climate change
On the basis of this point, we focus on the sensitivities of land carbon storage to the rising atmospheric CO2 concentrations and climate change at global and regional scales by multi-models, and compare the simulated variations between models that represent a potential source of uncertainty
They are detailed as follows: (1) in the experiment of only considering the single effect of atmospheric increasing CO2 concentrations, biogeochemistry only responds to the increasing CO2 concentrations in land models while the radiative forcing is fixed at the preindustrial values in the atmospheric modules; (2) in the experiment of only thinking of the single effect of climate change, the radiative forcing responds to the increasing atmospheric CO2 concentration while the biogeochemistry remains at the pre-industrial values in the biogeochemistry modules
Summary
Variations in the whole terrestrial carbon cycle are accompanied with increasing atmospheric CO2 concentration and climate change. By the end of the twenty-first century, there is an additional CO2 change between 20 and 200 ppm considering warming alone, while the higher CO2 values can lead to an additional climate warming ranging between 0.1u and 1.5uC [1]. With increasing CO2 concentrations alone there is a widely distributed terrestrial carbon sink of 1.4– 3.8 PgCyr during the 1990s, rising to 3.7–8.6 PgCyr a century later [13]. Such an enhancement of land carbon storage was accessed due to CO2 fertilization effects with a rate of 0.07PgCyr using simulation from Organizing Carbon and Hydrology considering fire disturbance [12]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
