Robustness and uncertainty in terrestrial ecosystem carbon response to CMIP5 climate change projections

By Anders Ahlström, G. Schurgers, Almut Arneth, Benjamin Smith. 2012

285 citations recorded by the source corpus.

We have investigated the spatio-temporal carbon balance patterns resulting from forcing a dynamic global vegetation model with output from 18 climate models of the CMIP5 (Coupled Model Intercomparison Project Phase 5) ensemble. We found robust patterns in terms of an extra-tropical loss of carbon, except for a temperature induced shift in phenology, leading to an increased spring uptake of carbon. There are less robust patterns in the tropics, a result of disagreement in projections of precipitation and temperature. Although the simulations generally agree well in terms of the sign of the carbon balance change in the middle to high latitudes, there are large differences in the magnitude of the loss between simulations. Together with tropical uncertainties these discrepancies accumulate over time, resulting in large differences in total carbon uptake over the coming century (−0.97–2.27 Pg C yr−1 during 2006–2100). The terrestrial biosphere becomes a net source of carbon in ten of the 18 simulations adding to the atmospheric CO2 concentrations, while the remaining eight simulations indicate an increased sink of carbon.

Subfields: Global and Planetary Change

View Paper: https://www.semanticscholar.org/paper/c0a44f5316a0160fdc7b32156574b7a87b562ac0

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In Global and Planetary Change

Citations in the corpus

Implications of accounting for land use in simulations of ecosystem carbon cycling in Africa (2013, unknown): “…from a neutral or source to a sink state around 1960 as a result of saturation of land use expansion, accompanied by increased greenhouse gas emissions, raising the production enhancement of vegetation due to atmospheric CO 2 (McGuire et al., 2001; Le Quéré et al., 2009; Ahlström et al., 2012b).”
Grasslands may be more reliable carbon sinks than forests in California (2018, background): “The ability of LPJ-GUESS to capture net carbon uptake responses to drought in the middle latitudes adds confidence to our prognostic modeling of future C storage in California (Ahlström et al 2012).”
The dominant role of semi-arid ecosystems in the trend and variability of the land CO2 sink (2015, background): “Modelling studies suggest a large uncertainty of the future magnitude and sign of the carbon 65 sink provided by terrestrial ecosystems (4-8).”
Tundra shrubification and tree-line advance amplify arctic climate warming: results from an individual-based dynamic vegetation model (2013, background): “However, releases of methane (CH4) and CO2 due to enhanced soil decomposition, enhanced thawing of permafrost and increased wildfire could outpace carbon uptake in the future (Friedlingstein et al 2006, McGuire et al 2010, Ahlström et al 2012).”
Reliable, robust and realistic: the three R's of next-generation land-surface modelling (2014, methodology): “This seems to be precisely the situation currently observed with coupled carbon cycle-climate models, as reported in AR5 (Ahlström et al., 2012; Anav et al., 2013; Arora et al., 2013; Jones et al., 2013;5 Todd-Brown et al., 2013; Ciais et al., 2014).”